Let's take a closer look at the renal corpuscle. The renal corpuscle consists of the glomerulus. The glomerulus was the capillary bed. So glomerulus contains blood and Bowman's capsule. Bowman's capsule is where the filtrate goes. The blood parts, plasma, flows out of the glomerulus and into Bowman's capsule. It's caught in Bowman's capsule. So let's draw this again so that it's nice and clear. And remember, how did blood get into the glomerulus? What was that? This is my glomerulus right here. And how did blood get in there? It came in through the afferent arterial. This is glomerulus, and it left via the afferent arterial. So you're good with that? Now, we have to draw Bowman's capsule. Bowman's capsule is a double-layered structure. You can imagine Bowman's capsule is like a balloon. And the glomerulus is a net of capillaries that were punched into the balloon. Is any part of this seeming somewhat familiar? Yes, look at my balloon. The glomerulus is inside the balloon. The balloon wraps around the glomerulus that punched inside it and then still contains the air that was in the balloon in the first place. What? You actually have a visceral layer and a parietal layer of Bowman's capsule. And let's make sure we have our terminology. Hmm, that's exactly what it's called. You tell me, my little stick pointer is on the parietal, parietal layer of Bowman's capsule. Now my little stick is on the visceral layer of Bowman's capsule. The visceral layer of Bowman's capsule is unique. It's actually a group of cells that are smashed on the capillary bed. And they have these really unique characteristics. The capillaries are really unique. They have these slits in them, so they're super leaky capillaries, which is very unusual. And then the visceral layer of Bowman's capsule has these parts of the cells that kind of like these little fingers that come out and interdigitate and create this sieve like a filtering system. Well, that's exactly what it is. It is a filtering system. Like remember when you were a kid and you'd go to the beach and you'd have that little tray with all the holes in it. What is that thing? It's a filter. But you'd like throw the sand from the beach in it, and then you shake it all out and you find seashells and crabs and who knows what other cool things you find in there. That's what I'm thinking about. But I want to show you a picture, someone else's picture. This is also from the OpenStack's textbook. Dude, those guys are phenomenal. But look at this thing. You can see here it's blood. Here's my efferent arterial. Here's my afferent arterial. The blood comes in and look at how the visceral layer of Bowman's capsule is like smashed onto the capillaries themselves. The capillaries are a knot. This is just so nice how it's shown. The parietal layer of Bowman's capsule is, what kind of tissue is that? It's simple squamous epithelium. Look at the space in between there. That's the capsular space. That's actually an actual, it's not a potential space. It's an actual space where the filtrate gathers. And then look at who's this. This is proximal convoluted tubule. So once the fluid comes out, it's going to go into this tubule and now it's going to be in there to do its thing. This, I know it looks familiar because we looked at this thing on day two in this class. And this is day 22. Holy crud, time flies when you're having fun. So 20 classes ago, we actually looked at this slide and we looked at the parietal layer of Bowman's capsule as our example of simple squamous epithelium. Aw, this is so fun. All right, so I think did I label everything capsular space? I didn't. I wanted to tell you that the visceral layer of Bowman's capsule, the cells that make up that visceral layer, they're called podocytes. And I think of pod, foot, toes, and these are like little toes that are sticking out here. So these are podocytes. And then what else? That's it. Okay, now we get to look at three parts, the histology of three parts of our kidney because we can actually tell nephron parts when looking in at our kidney slide. So let's get started on that.


Hello and welcome to today's edition of Frightfully Forgotten, but first, what are we drinking? Season of the Witch, my bog. Now, did this pretty hard the other night? We're going to be talking about 1981's Dead and Buried. Directed by Gary Sherman, and he did raw meat, mind the door! And he also did Poltergeist 3. James Farentino is in this, Lisa Blount is in this. She was in Prince of Darkness, of course. Robert England is in this, Jack Alberston is also in this, and he was Grandpa Joe in Willy Wonka in the Chocolate Factory. Dead and Buried starts off with this photographer kind of on the beach in Potter's Bluff. He runs into this really good looking girl, starts shooting pictures of her, and it's like, ah, this is kind of a little too good to be true right now, right? Hey! Hey now!  They all whack his shins with a crowbar?  The police get called to the car accident that's happened on the highway. The Sheriff Dan Gillis shows up and see the poor guy burned in there.  So Gillis goes to visit Dobbs, the coroner at his office. Did the burns happen from that accident, or was he burned elsewhere and placed in the car? Learn that Dobbs is a little eccentric, a little odd, loves his job, and he considers it an art.  The Sheriff goes to the hospital to see this burned victim, a very terrifying image of this guy in the bed all bandaged up. And he's got no lips, you just see his teeth? Just before the Sheriff is led inside, the nurse shows up, and while you might recognize her, she's the girl from the beach. The Sheriff goes in to conduct his interview, the guy's dead, his lead is gone! The family is driving through this town, and they stop at this diner to get directions. And you kind of look around, and you see all the patrons and the employees, and it's all these people that you've seen taking the pictures at these burger scenes. One of the guys who actually helps them give directions is the guy who was burnt alive on the beach. So they're driving, and someone kind of runs in front of the car, and dad swerves, and he hits his post, and the kid all, uuughhhhhh, uuughhh, uuughhh. So they go to the nearest house to get help, and the house's abandoned, and it's all cobwebs, and it's a great dark atmosphere. All these people start entering the house with machetes, and all these weapons, and their cameras again, and they're taking pictures of this family, and the family tries to get out, and they eventually do. Town's folk gets on the hood of the car and starts like smashing the windshield. That same night, Dan Gillis is driving, accidentally hits a pedestrian. There's an arm that's been ripped off the guy's torso and stuck to his grill. And it's moving. This guy gets up, and takes his arm back, and runs off.  He takes it to the town doctor to get them analyzed. Dan Gillis gets the information back, and the little skin fragments and stuff are like four months deceased. He goes to the cemetery to dig up the grave of the guy who burnt alive in the car. Nobody's in the coffin. Dobbs comes up to him and starts complaining to him that there's a body missing from his morgue. And Dobbs is also very, very keen on covering it up. So he starts doing some digging on this Dobbs. It is wife. She gave him some footage, and he's taking it down to get developed.  There's all the town's people around watching and taking pictures and sort of almost getting involved.  Laughing and having a gay old time. Dobbs!  That's where we're going to end it because the story continues to unravel. Which is one of the hallmarks about this movie is the actual story. It's so different. There's nothing like it. It's so original. It's so original. It's a small town. It's got some little secret, but it's a crazier secret than you'd ever expect. This harks back to the mind control voodoo zombies that are doing the bidding of a higher power. There's also the murder mystery aspect of it. You see who's doing it, but why are they doing it? The why is the big question. Why are they gathering in droves and taking pictures of people and murdering them? The atmosphere of this movie is really cool. It's dark and dreary and always cloudy and kind of raining. It almost feels dead. Exactly. The town does feel dead. The effects were done by the effects master himself, Stan Winston. He's done the thing. Terminator 2 aliens. Tons. The guys won multiple Academy Awards for his effects work. That's why these are so good. The burned body when he's hanging upside down. The car is like, ooh, that looks pretty goddamn real. The acid? Yeah. Pump the acid through the guy's nose and see his face melt? There's a really, really cool scene where it shows Dobb is preparing a body, time-blapsed and it shows him basically take the face apart and putting it back together again.   I know she's going to come back to life. Where's going to be the cut between this dummy and the actor? Yeah. It's like something she's blinking and like...  CGI ain't going to do that. The acting for this movie too is just top notch. Yes. You believe everything that's happening in this town, right? Especially like the dynamic between the sheriff and Dobbs. Feel it. You know that they're supposed to be working together. But you feel the... Tension. You feel the tension, right? Exactly. Yeah. It's cool. Dobbs as being kind of the villain of the movie. He's great. When you find out what he's up to at the end and his motivation behind what he's doing, it's so original. There's nothing like it. It's totally put Dobbs as being very underrated movie villain. You don't really see it coming until like the very end, right? Dobbs! Which leads us to the perfect ending, twist to this movie, right? And it's a perfect payoff because you're never bored through the whole movie. No. You're also kind of riding this wave of like the investigation. And then at the end, it's like, oh my god, I saw all the clues throughout the whole movie. Yeah. Wicked. It was a crazy, cool twist at the end. It does everything to the best of its ability for 1981. For 1981. This movie has everything that a horror movie lover could ever want. So if you haven't seen Dead and Buried, please, please check it out. And it's funny because the name of the movie isn't really what the movie is about. It was a little misleading. But please check it out. And until next time, Keep drinking. Making golly's weird. Yeah, I know. It sounded like... Just drinking or something.  I don't know what the movie is about.


All right, so probably we're talking about two points. The first is high-contention on the M-Map lock for multi-priority tasks, as everyone takes a page vault, takes the M-Map sum, and the other is a priority version between tasks, which are monitoring a low-priority task, which is monitoring a high-priority task, and then it blocks and everything goes to hell because the RWCM is fair, which it needs to be, but it does mean that we don't do priority inheritance, and so everything is awful. So last year, we presented three options to look at. Michelle presented speculative page vaults. Sirin presented RCU lookup and VMA lock, which is what we actually ended up doing, and I presented full RCU page vault handling, and everyone said, oh, my God, that is far too scary. We're not going to do that. So here I am talking about what Sirin has done. Since last year, we replaced the RB tree with the Maple tree, and that went into 6.1. Thank you very much, Liam, and we are still dealing with a fallout, but that's... All right, when you're doing something big for the first time, it's tricky, okay. And now in 6.4, it's actually been merged. If you're running 6.4 RC1 on your laptop, you are running Sirin's code. John put up this very helpful write-off of exactly how it works, so I am not going to start talking about how it works. I'm just going to assume that you read the... that you did the reading. All right, so what is coming up? We have patches posted to the main list for handling faults in fileback VMAs with up-to-date pages in the page cache done under the same RC protection that we currently do for anonymous pages. We also have patches for handling faults in pages which happen to be in the page cache, sorry, in the swap cache. All right, so again, that's anonymous, but so it's just extending the current patches that exist. So right now, if we hit one of these two cases, we will fall back to taking the M-Maps M, sorry, the M-Map block. And if you add these patches, then it expands the number of cases in which we will handle it all under RCU plus the per VMA semaphore protection. So what I want to talk about, because that's just patch review, right, and debugging. So I want, or we want to talk about should we wait for IO under the protection of the VMA sem or should we handle it similarly to how we handle the M-Map block today where we make sure to drop the M-Map block before we wait for IO? And a similar question for starting IO. We would like to talk about reading various files in slash proc without the M-Map block. Handling faults in VMAs which use user-faults-fd right now for you, if you use user-faults-fd, we just always fall back to the M-Map block. And then VMAs which are owned by device drivers. We want to talk about removing the M-Map block entirely. And we want to talk about handling faults without the VMA lock.  And I have a slide for each of those. If you look in file-map.c in the page-fold handler, you will see that if we would need to sleep, that is we find a page in the page cache and we know it is not up to date. In order to prevent contention on the M-Map SEM, we drop the M-Map SEM. So we take a reference on the file, drop the M-Map SEM, and then we sleep in the page-fold handler waiting for the page to come up to date.  Should we keep this model? I think actually the swap and the file cases are not the same here because in the file case, you can make a good argument that the contention that could happen here would be if someone unmaps the file while they're accessing it. And then that means they have two threads that do conflicting operation and it's kind of expected that one will have to wait on the user somehow. So I think you could get away with waiting while you hold the VMA log in that case without having to release the VMA log while you do that. I think in the Anon case, that argument doesn't really work because VMAs don't really map into process-visible things in the Anon case. And so I see them as a really different case for VMAs. I would like us to have something more granular than for VMA logs or to deal with, find a way to prevent that sort of false conflict from occurring in the Anon case.  So I want to check that I really understood what you said. So what I think you're saying is that a process can call malloc twice and those two malloc call, and they're big so each one ends up by G-Libc calling M-Map. And those two happen to be combined into the same VMA because we're trying to optimize and save space and memory and time and so on. And therefore, there are conflicts that the application could not be reasonably aware would happen. Yes. Okay, good. I appreciate you letting me have this time to learn. Have you done any tracing to see what, like, you know, keep the M-M lock held for this process and running something like a lock stat and looking at the contentions that may arise. So instead of just this, you know, hand waving saying, yeah, what do you believe? What do you believe? What do you believe? Actually run some actual tests and maybe even under like a production, I don't know if you want to try it on a production environment, but if you're actually seriously doing this, trying to get some way of doing some sort of tracing, there is lock contention tracing that you could do to enable and seeing how much contention there is that causes this to get some real numbers. Look, we have regular bug reports of a unnamed large database product that tends to care about M-UPSM because whenever you just start aggressive monitoring, like PROC-PIT, whatever, that really requires M-UPSM, that can be visible really heavily. Yeah. Into the slide where you get rid of it. That's the last slide. All right. Should we be willing to start IO without the M-Map lock? So the, I think the answer is yes. And it's certainly based on everything that I've just heard about and on being different from far memory. This always sounds like it's a good idea to start it, because we're not saying you can't sleep during the page path and holding the various locks. Of course you can sleep, you can sleep to allocate memory if you absolutely have to. So starting IO, so I think we're still saying you can call down into device drivers with M-M locks held. We're not trying to get rid of those paths, but we're, so there's no reason, we actually, it's actually causing us problems. We should do our best to drop all the M-Map locks before we start calling into device drivers. Okay, good, moving on. Monitoring without the M-Map lock. Michael's problem. Or maybe Facebook's problem and of course unnamed database problem. So this actually is a simple matter of programming, at least for some of them, right? The M-Maps file, we can just do this all under the R-C-U lock today and it is simply a matter of the programming. I mean, since the M-Maple tree went in, so we've actually been able to do it for like three kernel releases now. It's just that there's not been time to write that code. But for the S-Maps interface, this gets a bit more complicated because we actually need to prevent page tables from being freed. So the ways that you prevent page tables from being freed today, you can take the M-Map lock. On X86, you have to disable interrupts. On other architectures, it's sufficient to hold the R-C-U lock, but on X86, you actually have to disable interrupts and I, this just feels like stupid legacy and we should get rid of it and make X86 the same as everybody else and I'll see you free the page tables. So it's not even fully true that disabling interrupts helps because you do that to block the inter-processor, interrupts that flush the TLBs and that effectively blocks the removal of page tables. But there are the para-viltralized variants that don't use the IPIs and then those have to use the R-C-U freeing. The argument that's been made is that the IPIs also are effectively the same, or sorry, disabling interrupts is effectively the same as being an R-C-U critical region. So it effectively does both and it also allows you to make this weird X86 inference that you're blocking IPIs and thus you're blocking the non-R-C-U page table path, which is completely nuts. I've been hoping, Matthew, that your struct page rework will let us put R-C-U heads in all of the page tables, struct pages, so we can R-C-U free everything everywhere for every architecture, but I don't know if I'm just being wildly optimistic. So there's already an R-C-U head in struct page. So I think we can already do this on every architecture, I think. I don't think there's a reason not, I'm being told it's overloaded by some architectures, and yes, it is, but not at the point where they're being freed, I believe. I think at the point where they're being freed, they will never be written to or read. No, no, I know they are overloaded, but I don't think those overloaded fields are used at the point where we're trying to free the page table. Michelle is saying that it's done differently based on different architectures and different config options. Apparently, it actually allocates memory. It doesn't actually use the R-C-U head that's currently in the struct page, which I didn't know, so I've just learned that as well. And to add to this, it will also depend on the config option for split PTL logs. There is also a range there. So in the debugging, that option is enabled, which is enabled by one of the debug options for slab, I believe. It will also add some issues there because PTL is not part of the entry anymore. Mike wants the mic. I think it's feasible to do R-C-U-free of page tables and we can move, we kind of can move the R-C-U-head or create a special R-C-U-head in the page table type union. And then they use that explicitly to make R-C-U-freeing of the page tables. Jason, over here. I think it's a great idea. But there's still this confusing comment in gup that I was looking into last week that says, you still can't use R-C-U here because of some reason it doesn't make sense. I tried to deduce what that reason was and I don't think it makes sense or at least it doesn't make sense today, but maybe somebody knows better. I don't know. He said that Jan Horne explained it to him but now he doesn't remember the explanation. He might be a good person to ask. All right, so general consensus is we want to do it. We just think that there might be demons. I think it would be extremely useful to write that to the mailing list. There are people looking for projects and especially as you say, proc maps seems to be R-C-U really easy, so low-hanging for somebody to look into because most people in this room are really busy so somebody else might be looking for a nice little project. Without having that described, I'm regularly asked to share my to the list. Same here. So yeah, this is a good one to pursue for somebody to take on because it should be easy, but it's going to take testing. Suren. So yeah, I looked quickly at user fault D and it looks very similar to the swap case. So basically we can drop the, what we do right now is we are dropping a map log before notifying the user space that hey, you need to handle this page fault and then we are retrying. So I think the same approach will work with per VMA logs unless somebody can tell me why it wouldn't work, but yeah, maybe Peter can. I would like to see the patch. I think what you said is correct as per our discussion privately there. So I assume what user fault FD does is quite simple that it yields itself and wait for some response that is resolved. So I think it's simpler than the swap. Okay, so once we are done with swap, I think I can apply the same pattern. Fantastic. All right, so one final thing that we probably want to start talking about is handling faults in device driver VMAs under this improved locking scheme. But device drivers may use the M-map lock to exclude faults.  So I don't intend to go through and audit every device driver that supports a fault handler. One really easy way for device drivers to make use of this is actually to use slash ab use file map fault. There's absolutely nothing stopping a device driver from putting the pages that it owns into a radix tree attached, so into the x-ray that is attached to the i-node i-mapping, and use all of the stuff we have currently available for file systems. I'm seeing a pained expression and I'm not surprised. There may be very good reasons not to do that, but it is one possibility. The device driver is also going to need to attest that it does not drop the M-map lock in its fault handler. I don't believe there are any that do that today, but it's something that they might be doing. Yeah, David. Just like you mentioned something very interesting that sometimes the M-map lock is used to block page faults. What would currently happen if you do fork concurrent to a page fault? Like with the fork that takes the M-map, write lock, block, any kind of page faults because I think like if there's a VM, like would we go ahead and lock each and every VMA doing fork in order to... So you could get concurrent page faults with... Uh-oh. Oh, I suspect that there is something broke. Be ready for surprises. Yeah, so M-map lock would not take a page fault. Sorry, page fault will not take a M-map lock. It will take per VMA lock. So unless you are affecting the same VMAs, it wouldn't be affected by the fork. Like in the general case, device drivers have to assume their VMAs can be forked. And most simple device drivers, they have like some very simple thing that they're doing in the map. And if I fork or I M-dupe or something, I get multiple VMAs. I can't really rely on the M-map lock for serialization. Or if I am, I'm already broken with fork, right? I think that's good logic, David. Please make sense to me. After the per VMA lock work, page fault can happen concurrently, right? And before that, we can't. Before that, it would happen concurrently in multiple processes if you forked. Why not? Before that, the fork takes right lock and every fault handler takes read lock, which will block at the right lock. No, no, no, not during fork, after fork. Oh, after fork. Right, I have two VMAs. Two VMAs, two processes, two M-M structs, two M-M-M blocks. There's no serialization there, right? Right now, the per VMA locking is only done for unknown VMAs. So I think you don't hit that issue with drivers yet. And I think when we want to generalize that, it will have to be on a per, like with some sort of a white list. Why not? I'm just saying, hey, we can do it everywhere. I don't think that's gonna work right away because there are drivers that expect to be serialized on the M-M-M block. It's not just if they're gonna release it, it's like there are some that expect that serialization to happen right now. I have not in detail. I know that Peruv does some really weird things. Like you can M-Map some pages that will hold a log of events. I don't know exactly what they do, but they do weird things with the M-M-M block. And if you just try to have them when concurrently, I don't think that would, you would have to understand what you're doing, which. So the last push on the side is that we may want to be advising device driver writers to implement the M-Map pages function pointer as well as the fault function pointer. So M-Map pages actually runs protected by the RCU read log now as of, I think, 6.3, certainly 6.4. So they definitely can't seep during it, but it is going to be the most efficient way to get your pages into, mapped into user space. So Kristoff made a nice series a while ago to try and simplify the creation of ANON iNodes and device drivers. That if you want to go down this path, it would be probably essential to get that work completed and merged. I think there was some discussion with Al Viro or something and it never, it just kind of dropped it. But currently if you want to get an ANON iNode that's suitable to hang map pages off, it's a pain. Okay, but you can implement your own map pages because you do already have your own fault handler. In that same struct, you have a map pages and your map pages can do anything. It's not, you don't have to use file map pages. You can do anything. Okay, but you were talking about putting it in the x-ray that's essentially. Well, I was suggesting that that is one thing a device driver could choose to do. It doesn't have to implement its own fault handler. It could instead put pages into the x-ray and pretend to be a file system and do far less work all by itself. I don't know any device driver that does that today. It's always, because I'm a device driver. I'm not a file system. They usually don't have struct pages in a lot of cases. Well, it depends on your device driver. I've seen it both ways. Yeah, yeah, I know both ways. Yeah, several cases, okay. All right, well, I'm conscious we're into coffee break. So getting to my penultimate side removing the end map lock entirely. So I've done everything. I think I'll just try to make a point. You may want to unmute. I'm sorry? I saw a little racing hand. I don't have any control over what's going on online. Okay, my question was pretty much dealt with. It was which I know to use because for block devices who do have unique I-Node for all device nodes referring to the same device. For character devices, we end up with I-Nodes of device nodes on slash dev or wherever they are. And you can bring them to Helen Beck. So you would need some mechanism that would give you per device I-Node. And we definitely don't want that for every, I don't know, pseudo-TTY or whatever. It's not like block devices where we would do it uniformly for everyone. Some variation of NONI nodes would be used that way, I guess. I'll need to look through the Christoph's page set again to give anybody details about that pretty much deals with. The question I have. Great, thanks for that, Al. I withdraw the suggestion of pretending your device driver is actually a file system. All right, so that's also a variant. So something that we would like to get to is just to remove all use of M-Map block when handling faults. And I think this is a multi-year project. Then we're clearly capturing the biggest wins first. And at some point, it's going to be kind of like the big kernel lock, right? That it's just, we've got these tail end things that are holding us, getting rid of it, and eventually we will get rid of it properly. Maybe this is not an analogy that makes too much sense to people. I know there's a number of people in the room who came here who was like, what's the big kernel lock? We got rid of it like 50 years ago. But we would like to remove use of the M-Map block to protect the VMA tree. So the VMA tree doesn't really need to be guarded by a semaphore. We can actually guard it with a spin lock of its own. So this is one way that we can go. We can start splitting out the various different things that use the M-Map Sem into their own lock. It's not entirely clear to me what the M-Map block is. It's not entirely clear to me if and how we can do that. There's a bit of tie-in between the reverse mapping locks or the M-Map lock and the Arm-Map locks. And there was a previous item to make the Arm-Map locks a non-blocking, but that was reverse, like that didn't really work out for some use cases. And so I think because of that, because of the tie-in we have between the two, we have to update the two canner at the same time, it might be hard to make the M-Map lock be non-blocking. Yeah, no, understood. I have put very little thought into all the details. So yeah, absolutely. So, plus slide. So handling faults without the VMA lock. So we are at the point where there is no lock contention. But we may have got to a point where there is cash line contention. So if we have a large VMA, particularly like Michelle was saying for anonymous, where we have a very large VMA and we have a lot of page faults being handled in that VMA, that all the threads are bouncing, the cash line that contains effectively the ref count, I mean it's done as an RWCM, but we're using it as a ref count. We're bouncing that ref count around between all the different threads as they start and finish their page faults. So, and this is where we're going to need to use Perth. We're going to need to study, where are the slowdowns coming from, where is the contention, if that's where the contention is, we do have a path. And it's the one that I suggested last year. I have gone through in detail and figured out, can we do it and we can. But there are complexities. Like we have to allocate page tables while we're holding the RCU read lock, or we have to drop the RCU read lock, allocate the page tables and then come back. And so I've been talking with Paul McKenney about how we might be able to do that in a more efficient way. It's kind of nasty, that we didn't come with any nice ways of doing this. Yeah, and then we start to go through all the different things that we're doing right now under VMA lock protection. We look for our lowest hanging fruit. So being able to allocate in certain new and non pages. And again, we would have to say, well, we're only protected by the RCU read lock at this point, like allocating memories kind of hard. So do we do a GFP no weight or do we drop the RCU read lock and restart after we've done an allocation? Yes, Stephen. I just want to real quick, I know we have coffee and everything that, but are you familiar with the runtime verifier or run time verification that was? I briefly skin the patches. So basically the idea of it is it hooks into the trace events and you create a model. If you want to actually follow the correct, you actually define the model that you want. And if it ever goes outside that model, it could panic, print, warn, whatever. So it's something like this, if you want to make sure you assume that everything's happening correctly, if you have the correct trace points in there, you could develop the model, put it in, and you run it, it's made to run on production. Two as well. Just want to let people know that this exists. That's cool. Thanks, Stephen. Yeah, so when we get to this handling falls throughout the VMA lock, we then have three or four different ways where we might be in different contexts, where we might be in a fold handler, we might be holding the M-Maps, we might be in pure RCU mode, we might be in RCU mode, but actually protected by the VMA lock. And so there's all these different fallbacks and scenarios and it does start to get quite complicated. And I think, last year I was informed the complexity scares people and I hear you. So we're only going to go this far if the performance warrants it. Any last thoughts? Sounds like coffee time. Oh, Michael. I would like to, for doing Forge without the VMA lock, I would like to do that for Anon because of what I was saying before that the per VMA locking is adequate for FI's and for Anon it's a bit more questionable. Like there can be false conflicts that are kind of unavoidable with Anon. So I think avoiding taking that lock for Anon would be good because of that. Yeah, and it's totally possible to get that building from where we're at with Soren's Patch. We can get there. We're just going to need to bring data to show that the complexity is worth it. Thank you.


My name is Nadine Nicole Williams. I'm an LN2, but right now I'm in law school. I'm a law student slash yoga instructor. I have a son. He's 14 now. I'm a single parent, so I came into the Navy as a PS. But even though I liked it, I wanted more. Like, I knew I still wanted to be a lawyer. I still didn't know how, what route I would take or even if it was possible at that time. I just knew first I want stability for my child. And so I joined the Navy. And once I realized, okay, I like this. I can do this. Now let me start planning my next goals. And so I decided to go back to school, which I did. I got my undergrad on active duty. And then I converted to LN. And then now I'm in law school. I knew when I was like little, I wanted to be a lawyer. And I didn't know how to go to law school on active duty. I had researched different schools. So I decided career intermission would be the best choice. When I was taking the undergrad classes and doing that, I thought at that time that was the most busiest. I thought it was the most difficult thing to do. Not so. Law school is the busiest I've ever been in life. So at the time I thought it was busy because I was going to school full time. And I took classes online and I would come home and get my son from school, cook dinner, do homework. We would sit around and say, we want to do homework together. And then, you know, wake up the next day and do it all over again. It was busy. It was hard. There were some days that I just, I stressed about it constantly. I didn't do anything except for class, school, reading, class, school, reading. Maybe just like a little bit of sleep. Like if I had four or five hours of sleep, that was good for me because I wanted to reach that goal. I got into teaching yoga not because of the money, but because law school is stressful and I wanted to be able to work out. And if I'm teaching a class, then I have to do it. There is no, oh, I have to read the assignment. There's no, I have to go and teach this class. Oh, that's how the money is a lot less, but the perks are great. You can do this. You will do it. Calm down.


The results of this study suggest that a large number of college students in Lebanon are experiencing food insecurity which is associated with poorer mental health and well-being outcomes. This highlights the need for public health programs and interventions to address food insecurity and improve student health-related outcomes. This article was authored by Rita Ohtani, Lama Matta, Samma Karibi, and others.


Boom, blows Tom Zivini's head right off, like. That's one of the best headshots ever. Tom Zivini earned his pay big time.


Biostatistics. A lot of people have a tendency to get intimidated with biostatistics, but there's absolutely no need to. Hi, my name is Arun and I'm an instructor with MedSmarter. Taken from someone who has done a master's focused on biostatistics that's entirely learnable. The main thing is you take complex concepts and making them into more simple terms, for example. I'm a big golf and tennis guy, so it's like working on your golf swing or tennis swing. You break it out in more simple terms and then based off those simple terms and concepts, no matter how the questioner will ask you a question, you'll be able to answer it no matter which way. And that way you can answer any question with great confidence. Now let's get straight to it. Let's get to Biostats made easy. The first thing we're going to do is a 2x2 table. The thing about a 2x2 table is if you know the 2x2 table, you know everything or you will know everything. But if you do not know the 2x2 table, you will know nothing because you know nothing, John Snow. You know nothing, but if you do know the 2x2 table, you will know every single thing. So this is a 2x2 table. The main thing you want to remember is what's up top is reality. That's your R. That's actually what is true. What's out here is your test. This is a man-made test, right? So your man-made test tells you something is you have a disease, you're positive for it, or you are not positive for it. Here in reality, you have it, or in reality, you don't have it. Let's say it's diabetes. So let's say in reality you do have diabetes. In reality, you don't have diabetes. Here, your test will tell you if you do have diabetes and your test is telling you if you don't have diabetes. So if you do have diabetes and your test says you have diabetes, awesome. True positive. Here, if you don't have diabetes and your test says you don't have diabetes, then it's a true negative. So now you're all set, all right? But let's say that you don't have that. So the key here that you have to remember is everything is based on the test. What does that mean? That means that, let's say here, you don't have diabetes, but your test says that you do. The first thing you should think to yourself is this is a positive and this is a negative. Therefore, that is false. But what goes here? Go by the test. So it's false positive, all right? So then here, you do have diabetes, but your test says that you do not, all right?  And what goes here? Think negative. Think it has to go by the test. So negative. So false negative. Therefore, true positive, false positive, false negative, and true negative. Because once you get this, you can build off everything really fast. Two by two square plus, minus, reality, test, plus, minus, plus and plus go together, true positive, minus and minus go together, true negative, plus and minus. You think to yourself, okay, well, that's a false. What test is it? Plus, false positive, plus and minus go together, false, what test is it? Negative.  For now, this will be a separate video later. But for now, just think to yourself, this is a type one error, which is false positive, also known as alpha. And your false negative is a type two error, also known as beta. How do you remember? Just think to yourself, one and A are both higher or above. So it's on the top here. And then two and B are lower. So naturally, they're lower. All right? So type one and alpha is up here. That's a type one error. And this is a type two error. And then beta. And don't get it confused as far as reality and what your test actually is. Because just remember, reality is up top. That's the truth. That's heaven. That's what's up top. And then your test is on the side, which is man made test. All right. So now you have your two by two. So now let's move on to sensitivity and specificity. All right? So here you have sensitivity. And here you have specificity. Note that it goes in alphabetical order, S E and S P. So sensitivity is here. And specificity is here. When you think about sensitivity and specificity, think vertical, okay? And we'll explain why in a second. But as far as sensitivity is concerned, you have to think to yourself, it's the actual, it's the proportion of actual people that have the disease or actual positives that are being measured as such. And specificity is a proportion of people that actually don't have the disease that are being measured as such. So based off that, your formula is true positive divided by true positive plus false negative. Remember, go right down this way. All right? So that's your sensitivity and always start with the true. Then your specificity is your true negative because you always start with the true. So you're going up here, specificity, true negative divided by true negative plus false positive. As far as positive predictive value, think horizontal, okay? So then you go this way. And negative predictive value horizontal, you go this way. The difference with positive predictive value and negative predictive value is you're actually seeing how good is your test. That means when your test comes out positive, how accurate is it? When your test comes out negative, how accurate is it? Again, you always start with the truths. So this would be true positive divided by true positive plus false positive. And then here, you would have your true negative divided by your true negative plus false negative. Something important to note here is the difference between sensitivity and let's say positive predictive value. All right? Sensitivity is a proportion of actual positives that are being measured as such. And when you think positive predictive value, it's based on your test. Okay? So this is reality and you're measuring the amount of people that actually have it versus this is based entirely on your test. So why do you need to know this? See, let's say you tell your patient that they have diabetes or AIDS. And the patient's going to say, well, how sure are you that I have diabetes or AIDS? And that's when you can say, well, your positive predictive value or the positive predictive value of the test, let's just come up with a number, is 95%. I'm 95% sure that the positive test that you got was accurate. We at MedSmart are here to help you score higher on your USMLE Step 1. And hopefully our personalized approach will serve you well. And we will help you achieve your dreams of becoming a physician. Also, if you want to learn more about our courses and our tutoring, be sure to take advantage of our promo code below. And we can't wait to help you pass your test.


Now, the Romawine Company of Fresno, California presents... Suspense! Tonight, Romawines bring you the suspenseful play called The Burning Court, starring the distinguished actor whose current performance you have admired in the picture Laura Clifton Webb. Suspense is presented for your enjoyment by Romawines. That's R-O-M-A, Romawines. Those excellent California wines that can add so much pleasantness to the way you live, to your happiness and entertaining guests, to your enjoyment of everyday meals. Yes, right now a glass full would be very pleasant, as Romawines bring you a remarkable tale of suspense. And with the strange events detailed in John Dixon Carr's novel, The Burning Court, and with the performance of Mr. Clifton Webb, the two-bane narrator go down cross. Romawines hope indeed to keep you in suspense. A pleasant fire, charming company, and a hostess who realizes that tea served in the Russian manner is the only manner in which tea should ever be served. Yes, a heartwarming evening, Mr. Covington, in an extremely gracious setting. How fortunate that your uncle had the wealth to satisfy such an exquisite taste.  Now I believe we're all here. Ted and Mary Covington, Mrs. Henderson the housekeeper, Captain Brennan, I believe. Yes, and incidentally yourself, just who did you say you were? No wonder you police have had so much difficulty with the case. My name is Cross, good and cross, the writer. Well, why don't you say so? That book, A History of European Murder, that's yours, isn't it? Extraordinary. A policeman who reads. As a matter of fact, Captain, it's because of my latest book, Poisoning Throughout the Ages, that I happen to be with you now. Ted Covington there is a member of the firm which publishes my work. I'd never seen him until tonight when he himself told me what happened. He went back to last Friday afternoon before it was then that he began reading my manuscript for the first time. He began it on the train, the commuter's train, which every afternoon deposits him safely and soundly in this charming suburb of Crispin. That is, if you care for suburbs. At any rate, I imagine he was almost home by the time he finished the first chapter. Then he turned the page, attached to the following leaf was a picture and looking at it, the young man's stippen suddenly and all be cried out his shock. It was a picture of a woman. Under it was printed Mary Dubronich, convicted of arsenic poisoning. St. Petersburg, Russia, 1731. Ted Covington was looking at a picture of his own young wife, his 25 year old wife in an early 18th century costume. The face, the features were identical, even the name. Dubronich is his wife or was his wife's maiden name. No, no, no, it was ridiculous. This woman in the picture was one of his wife's ancestors, simply an amazing family resemblance. He wondered why Mary had never told him about. Ted Covington glanced down at the chapter to which the picture had been attached. It was entitled The Affair of the Non-Dead Woman. But then the train was approaching the station and he rose and walked out to the platform. Standing there for a moment, his eyes ran down the page. Mary Dubronich, it appeared, was quite the continental charm in her day. With the magnificent assistance of our snake, she had disposed of half a dozen husbands before she'd been caught. But caught she was. She was sentenced to death, the chapter concluded, and then beheaded and burned. And there, waiting for him up a curb by the suburban station, was the wife he knew so well. Ted! She was leaning, taught him now to open the door, smiling in that way he knew so well. Ted, what on earth are you staring at?  It's the street light, I guess.  Come on, get in the car.  Laughable? That's what it really was. All right, let's hear it. What's so funny? Oh, nothing, nothing at all, darling. I guess I just feel good. Oh, fine mood for dancing tonight. Dancing? No, Ted, you promised. You said if Uncle Miles showed a noticeable improvement, we could go to the club. You mean he's really better? There's no comparison. The doctor agreed with me. Darling, there's no reason in the world why we shouldn't let Mrs. Henderson stay awake for a change. No, do her good, the old wh... What is the matter with you? Oh, it's just that I started to call her a witch. It's a private joke, darling. A private joke. And, by the time there were home, it was even less than that. Ted was sitting in the living room. When Marie entered and moved toward the fireplace, he stared at her as she struck the match on the half-stone, touched it through the little rows of newspaper, stood back to watch the licking flames catch the charcoal, then the logs. As the light rose, illuminating her face and the lips barely parted in that ineffably curious smile, he would remind her again of her fragile loveless and his absurd reaction to the manuscript. He glanced around, but there it was on the table where he placed it when he'd come in. Deliberately, he turned from it and then back again. The manuscript had been moved only an inch or so, but moved. Keeping his back to his wife, he thumbed through that early chapter and discovered just as he was afraid he would. The picture itself was gone. For a long moment, he thought of what to do. Then, slowly, he turned around. This, uh, this book of crosses I brought home. Yes, dear. There was a story of a poisoner in it. It's funny. Her name happens to be the same as yours. Your maiden name at it. Look, darling, was she a relative of yours? Like Ted, you're serious. Well, in a way, yes. I don't mean it's really important. It's just that, well, when you run across a person who was a top flight poisoner a couple of hundred years ago and who's a dead ringer for your own wife, you want to hear about it, that's all. Ted, what on earth are you talking about? Darling, be honest with me. Didn't you look at this manuscript when I was out of the room? No. You didn't take out a picture of a poisoner named Marie de Blanche? I most certainly did not. Somebody took that picture out of the manuscript. Who could it be? Mrs. Henderson has been in the back ever since we came in. And Uncle Miles, he's in bed in his room. I'm sorry, darling. It'll turn up. Forget it. Maybe I am overworked. I guess a little dancing is just the thing I need tonight. When they returned home, it had happened. Mrs. Henderson met them at the door. Ted's uncle had taken a sudden turn for the worse. Hurry as fast as you can. We'll be right there. If you don't mind. Yes, Ted. Come, Mrs. Henderson, let's go into the living room. He had wanted to be alone in the room. Not because of his great attachment to his uncle, who, save or Ted himself, was the last of his branch of the Covington's, but because he had seen something. It was the silver cup under the edge of the bed. The cup of the late patient had used for his medicine. Ted moved over to it, stood down. There were still a few blocks at the bottom. And then, just as he was rising to his feet, his heart seemed to miss a beat. He had seen the other thing, Uncle Miles' cat. Two feet away from the cup, further under the bed.  Fearfully, he extended his hand. The cat was still warm, but quite dead. No one must know, not yet. There would be a funeral, a normal, official interment in the family crypts on the grounds. Meanwhile, the cat must be very disposed of, and the contents of the cup. The next day, at the chemists, he was told to contain arsenic. For Suspense, Roma Wines are bringing you a star, Mr. Clifton Webb, whom you've heard in the first act of the Burning Court by John Dixon Carr, which is Roma Wines' presentation tonight of Suspense. Between the acts of Suspense, this is Truman Bradley for Roma Wines. We now quote a brief word from the renowned hostess Elsa Maxwell. I've found that one of the smartest ways to entertain during warm weather is to serve tall, ice, first quenching Roma refreshers made with distinguished Roma California wines. And it's so easy to enjoy frosty, satisfying Roma wine and soda. Simply half-fill tall glasses with Roma Burgundy or Sautern. Add ice cubes and sparkling water, and sugar if you wish. For a decorative touch, garnish with cherries and slices of fruit. And be sure to use Roma, for Roma wine is always uniformly good, the happy result of selected grapes. Carefully picked at the very peak of character in California's choicest vineyards, gently pressed, then guided unhurriedly to perfection for the ancient skill of Roma's famed wineries. Yet, good as it is, Roma wine costs only pennies a glass. Remember, because of uniformly fine quality at reasonable cost, more Americans enjoy Roma than any other wine. R-O-M-A, Roma Wines. And now Roma wines bring back to our Hollywood soundstage, Clifton Web has go down cross, writer and authority on murder through the ages. In the Burning Court, a play well calculated to keep you in suspense. Now, let me understand one thing, Mr. Cross.  Yes, less than 15 minutes ago. Then why not have Mr. Covington tell it himself? Primarily because I can tell it more beautifully. Uh, Mr. Covington. More tea. I'll get it for him, madam. You're very kind, Mrs. Henderson, but I'd rather you didn't miss even one facet of the story. Well, I'm not leaving, sir. The samovar's right over here. Excellent. I think that you should know that earlier tonight, just three days after his uncle's burial, Ted Covington sat alone in this room, contemplating some astonishing plans. This very night, long after Marie would retire, he himself would open the vault and exhume his uncle's body. A chemist had been engaged for a private autopsy. He was to look for traces of poison yet. Ted Covington wasn't so sure he could go through such a plan. The door opened, and Marie came into the room. For walking now quite softly across to the great fireplace, he studied her closely as she struck the match. Then touched it to the crumpled scraps of paper. Oh, I thought you might be a little chill. If only she knew the chill that was wrapped around his heart. If only she stopped shorting his thoughts. For now the glow had risen against that somewhat childlike face. And suddenly he saw for the first time the faint wrinkles of age at her eyes. Now the light was higher, and there there it was. The thin light creased like an almost invisible star that encircled about her neck. Marie Dubronich, he headed and burned in 1731. Yes, he was sure of it now. He had to go through with his plan. By the dim light of a lantern he set about his tusks, pounding his way through the thick concrete that now covered the family tomb, drawing open the great subterranean door, descending to the ink-black chamber below. He found the coffin net, rested it from its crimp, and placed it upon the floor. He unclamped the lid, opened it, and then, then, the word of shock leapt from his throat. Empty. Empty. Hey! Who's that? Who's that? I did, Mr. Covington, up here. Who are you? I'm the officer of the commission of police. Police? How did you... Who sent you here? Who told you about this? Well, your housekeeper, of course. You didn't think Mrs. Henderson saw the dead cat, did you? But she did. She also saw you bury it. That, as you know, was three days ago. So I've had a chance to do some delving. I must admit, Mr. Covington, that when I learned your wife's maiden name was Dubronich. Marie Dubronich, I was really quite intrigued. What difference does that make? Perhaps you don't know it, but that's a rather important name in crime history. But the same name, that's all. It's a coincidence, Captain. Yeah, isn't it? The case is full of them. Learned most of her poison tricks, for example, from a lover of longstanding, a fellow by the name of Krozitov. Go Dan, Krozitov. Kroz... Go Dan Krozk, let's say. Hasn't you a firm published books by a man by that name? Krozk? Oh, this is some kind of a joke. But what's even more interesting, Mr. Covington, is the fact that the name of the judge who sentenced Marie Dubronich to death by the burning court just happened to be Covington. Covington? Thurman Covington. An ancestor, wouldn't you say, of the man who just died? I was murdered. An ancestor of yours, am I dead? Well, but you can't believe any of this. This nonsense about a long-time lover. A vengeance through the ages. Well, Captain, Captain Brennan. Yeah, down here, Freddie. No answer at all. The place seems to be vacant. The Covington house? What? Yes, sir. Couldn't wait or so. Get out of my way. Hey, Covington, come back here. What's happened to my wife? You want me to stop him, Captain? Oh, let him go. We'll follow him. Good evening, Mr. Covington. Who are you? My name is Kroz, Go Dan Kroz, the writer. Kroz, my wife, what have you done to her?  Stop it! Listen to me. Why are you here? Why am I here? Because your wife, reading my chapter on Marie Dubronich, realized I knew more about the family than even she did. Because she found my phone number on the front cover of the manuscript. And because I know an exceptional case when I hear one. Does that answer your question? No, you know it doesn't. Can't you see I've got to... I've got to know whether... I see. Whether your wife is really Marie Dubronich, who is burnt by order of the Burning Kroz.  No, my boy. Marie Dubronich is no more your wife's real name than mine is Go Dan Kroz. What? Your esteemed wife, Mr. Covington, was adopted by people named Dubronich, remote members of the real family of poisoners. I can't believe it. What didn't you tell me? Because until I told her half an hour ago, she didn't know it herself. I'd learned it through my research. Oh, that's too wonderful. For years, Mr. Covington, that young woman has been haunted by the fear that she might be a poisoner by blood. You can see, can't you, why she was willing to lie, steal a picture, do anything to hide her past from the man she wanted to hold. Yes, yes, I can see that now. Mrs. Covington. You mean she's... Yes, Mr. Kroz. Oh, Marie, darling, you're all right. That will be our old, old friends of the police. Will you take them into the front room, Mrs. Covington? Meanwhile, you, my friend, will tell me everything that's happened up to now. Having just delivered your wife from the burning court, I'll see if I can save her from the electric chair. Sugar? Just pass it please, Mr. Covington. There. Thank you. Ah, yes. Truly excellent tea. Don't you agree, Mrs. Henderson? What? Oh, yes, yes, it's very nice. Yes. Well, that Captain Brennan completes Ted Covington's personal account of the events leading up to the present. Let us now consider that supernatural hocus-pocus of the body that walked out of the sealed-in tomb. That body, let's agree, that never was in that tomb. Never in that tomb? No, Mr. Covington. It was disposed of long before. But who could have done it? Who could have kept that body out of the tomb? Who, Mr. Covington? Why, you, sir. What are you saying? What are you driving at? I don't understand what you... It's very simple. You had to get rid of the body, Mr. Covington. You knew that eventually there was going to be an investigation. This, this is a joke, isn't it? A rather bad joke on your wife. From a few historical coincidences, you built a murderous in your own wife's image. I won't listen to this anymore. Why should you? Look, Cross, why would Covington here spend an hour smashing into a crypt for a body he knew wasn't there? Obviously, my dear Captain, could induce you to ask such a question, to impress you with his own innocence and his desperate concern for his wife's guilt. No, this isn't true. It can't be true. Of course not. Cross, just how, for example, could I have been in this house to poison my uncle and also at the dance that night? Easily. You simply left the dance that night. I left it. It was Marie who I explained how I looked for her. So you did. And you didn't see her, Mr. Covington, for the very good reason you weren't there. No, wait a minute. You were here, my friend, in this house, just as you were planned. No, no, you... Who but you then left you could so naturally have handed his uncle a cup, a cup presumably of medicine. Don't listen to me. And who but you of all those here would have the strength to carry that body to the furnace where it's now probably nothing but ashes? Lies. All lies. Why should I do such a thing? Why would I murder my own uncle? For the best reason that there existed a fortune. No, stop. You were the only heir. You'd get the estate, the money, the independence. Oh, please, Marie. Brandon, he's making this up. No, no, no. It isn't as bad as all that. Why, the police can never touch you. After all, where's the body? Where's the evidence? A truly delightful beverage. Yes, Mr. Covington, I'm sure you'll be quite comfortable in an asylum for the insane. And that is... Here, stand back. Stand back. Let me get to... Mr. Cro... What? What's the matter, Captain? This man's dead. Dead? And from poison, if I know anything. Poison from that glass of tea.  Nobody else was here. No, no. Too bad he didn't drink it as soon as you hoped. I didn't do it. Because a second ago, Covington, we had no evidence, nobody to use against you. But we have now, Mr. Covington. We have now. I arrest you for the murder of Godan Cross. Godan? Godan. So you've come back, dear Godan. Back within the hour. A little less. I know. There's no need to tarry longer. You were brilliant as ever, Godan. You perv in building the case against him. Magnificent in the suicide. Or even saw you take the poison. And I thought I'd caught you all the tricks. Closer now. Much more. Closer to the flame, Mary. Yes. Yes, Godan. Closer to me, my love. The Covington house burned to the ground. The body of Marie de Bronnich Covington was never recovered. And so closes the burning court in which Roma Wines have brought you Clifton Web as star of tonight's study in... Suspense. Suspense is produced, edited and directed by William Spear. Before Mr. Web returns to the microphone, let me say a word for Roma Wines, the sponsor of Suspense. Elsa Maxwell makes this timely suggestion on Father's Day next Sunday. Show Dad how much you really appreciate him by making next Sunday's dinner a festive occasion. Serve glorious Golden Amber Roma California Cherries as first call for dinner. Dad will enjoy the light nut-like flavor of this distinguished Roma Wines. Serve cool. Miss Maxwell has made a grand suggestion. And why not further delight Father with a gift package of delicious Roma Wines. Roma Wines always delightful, always uniformly delicious, are reasonably priced. And the next time you use Bermouth, choose Roma Bermouth. Zestful, full-flavored Roma Bermouth, blended and developed with all the traditional wine-making skill of Roma wineries, is made and bottled in the heart of California's famous vineyards. Yet surprisingly low-priced. Try Roma Bermouth soon, won't you? Now, this is Clifton Web, and now a serious word. This great Seventh War lone drive must be a success if our war against Japan is to be a success. Our fighting men are depending upon you to put your job over. It's up to you to buy bigger bonds and more of them than ever before. So please do it now. Ladies and gentlemen, next Thursday, at the same time, and Richard will be your star of Suspense, presented by Roma Wines. R-O-M-A. Made in California for enjoyment throughout the world. The Columbia Broadcasting System.


How's it? How's it? And today we're looking at a photographer who's controversial and intimate portraits of her own children rocketed her to fame. Today recognized as one of the leading artistic photographers in the United States, Sally Mann's photography is absolutely gorgeous and beautiful, and I can't wait to share it with you today. Thank you for joining me here today on the photographic eye. Sally Mann's philosophy and approach to photography is to try and make art from from the everyday ordinary. Throughout her career, Sally Mann has stayed close to her home in her native Virginia to create her photographs. And these are these are photographs that I feel almost seem to drip with affection for their subject, whether that's their children or the landscape around her. Sally's early beginnings as an artist started when she was in university. She was working as a photographer doing sort of grip and grin shots and group photographs of sports teams. When you look at some of her early personal work, it's easy to see the influences that she's getting from, you know, photographers like Edward Weston in her compositions, and there's a strong similarity between the two of them. Despite being well known today as a photographer who created loving portraits of her children, initially she thought that there were only sort of worthy of snapshots to put it into her own words.  And it was here when she was looking at the resulting picture that it occurred to her that right under her nose was this art, was the scope of art. And she didn't need to go off into the world to find art and that it was all around her. And this is when Sally, in her own words, has started to see things sort of around her life sort of differently and with the eyes of an artist. She'd already published a book of portraits called At 12 Portraits of Young Woman and this was her first foray into the genre that she would become known for. Of course, at the time she was photographing other people's children and one of the best known and striking images from this book is an image called candy cigarette. And I feel that that image most strongly echoes the later work that Sally would go on to produce with her own children. And in this book, At 12, The Portraits of Young Ladies, you can see that she's experimenting with various ideas about sort of composition and style. And some of this work sort of draws considerably from a photographer called Mary Ellen Mark, who was a well-known sort of documentary photographer. And it feels quite gritty. It's important to remember that photographers don't really emerge fully formed, as it were, from the womb. But, you know, they grow and they develop over time and drawing inspiration from other people is certainly not a sin. And with these portraits of Sally, you know, these are striking portraits of children of the cusp of adulthood. And they attracted a small amount of controversy, but nothing like she was going to get with her third book, which is called A Media of Family. Having grown up somewhat of a feral child through her own admission and not awfully keen on wearing clothes when she was younger, it seemed natural that Sally would gravitate towards photographing her own children in this state. And of course, while there's a lot of controversy around sort of the new child figures in this book, it should be noted there are so few of them that, you know, they constitute only like a tenth of the images in the actual photograph. So it was really a bit more of a storm in a tea cup. And one of the things that I really enjoy about this period of Sally's work is that it does capture this essence and this freedom of a rural childhood and almost like a kind of a nine-year or so never-never land sort of quality to them. And of course, you get this because first of all, Sally is a fantastic artist who can see art in the everyday. And the other is that working with a large format camera is a very slow and very deliberate process. And of course, it gives the artist time to reflect and create the precise photograph and work that they're looking to achieve. And I think it's a measure of Sally's expertise that she can blend this slow process with the free-spirited nature of childhood. Sally somewhat struggles with this concept of being an artist and she feels an enormous amount of pressure to continuously evolve and grow and improve her work. And it's this idea that each image needs to be better than the last one, that an artist can't back off as it were.  And if you look at her evolution as a photographer, you can strikingly see this in action. You know, she started off with photographing her children and over time they become smaller and smaller and smaller in the frame to what you're left with is almost a landscape photograph. And it was here that sort of two things came to pass. In 2001 the children were obviously getting older and Sally was also starting to get tired of photographing her children and wanted to do actual landscape photography. So she said that it felt like a useful segue to start becoming a landscape photographer and experimenting also with wet processes like amber types and tin types and collodion with her antique large format cameras which I feel lends her photographs in a serial quality to them that sort of echoes almost back to the very beginnings of photography and certainly makes me think of the alchemy of the whole process as taking something as elusive as light and fixing it onto a plate through an almost mystical and magical process. It's not almost a counterpoint to her earlier work with the children that her later work has focused on what happens after we're no longer here.  And she's done a series of photographs exploring this idea. I mentioned earlier that there was a series of photographs of her doing sort of dead bodies as they returned to their natural state in the land but she's also photographed the Civil War battlefields that dot the landscape of her home around Virginia. These early images remind me somewhat of Roger Fenton and Matthew Brady who were both photographers in the later part of the 1800s who covered the Crimean War and the Civil War respectively. Perhaps it's because of the similar processes used or because Sally's managed to capture the essence of these places long after these momentous occurred that I can sort of feel like she's sort of stepped back in time into the shoes of Matthew Brady walking these Civil War battlefields and saying, look, these landscapes have seen death and destruction but have returned to more sort of natural state but they still hold the essence of these great events. She's also created a series of portraits of a Larry who since the mid-1990s has had muscular dystrophy and she's been documenting his unfortunate progress of course through this illness. Especially more so given that Sally said when they met as late teens, Larry was a big strong hulking man and to see this wasting away has been a source of obviously distress but being able to document it in a way that makes it feel like it's art and again drawing on this idea that art is all around us has made these images extremely powerful. Sally is so much more than just a photographer who's photographed her children for a controversial book. Her photography both inspires us and it challenges us to look a bit more closely at the mysteries of the everyday world that surrounds us and again this comes back to this alchemy of photography and I hope it's inspired you to look in your own environment and see what can be considered art. I hope you enjoyed that look at the photography of Sally Mann and thanks once again for spending time with me here at the Photographic Eye. If you'd like to be notified when there are more videos like this one please do hit the subscribe button and the notification bell it would be so nice to be able to share these videos with you. Thanks ever so much again and I'll see you soon.


Hello everybody welcome back to another Adobe Premiere Pro CC 2021 tutorial. In this one I'm going to show you a wiggle effect or what some people call a wobble effect. I've heard it called a warp effect, a displacement effect, even a flag effect. Let me show you what it is. You'll see here that both the image and the text that I added in here are wobbling or displacing so to speak and you get that nice little organic fluctuation so to speak. Let me show you how it's done. I'm going to delete all of this stuff here and the first step here is I've got some video footage in the timeline. The next step I'm just going to drag and drop this image of my dog Kingston, my bulldog. I'm going to pull that into the timeline as well. I'm going to increase the length of the image so it's the full length of the video. I'm going to double click on the image so I can resize it and then I'm just going to put it down here and drag and drop it to the bottom right of the canvas. So there we go. We've got a video in the background and we've got my puppy dog in the background. Now the next step here is I'm going to create some text really quickly. I'm going to left click on the type tool or the text tool and I'm going to type in Italy because I believe this video is taken in Italy. So I'm going to type that in and then I'm going to move that somewhere, I don't know, somewhere down here so you can see. Let's move it up. Let's move it right here. Good enough. All right, cool. So we've got Italy in there and I'm going to increase the length of the text so that it's the full duration of the video as well as the image. So there we go. Now let's get into the technique. The first thing you want to do is you want to go to the effects panel here. For me it's right at the top right here. You'll notice I'm in the effects workspace and go to your effects panel. Type in, here's the one, turbulent. So once you start typing in turbulent you'll see that there's an effect called turbulent displays. Drag and drop that onto the text. When you do that it's going to warp the text quite considerably and that's totally okay. We want to now go to the effect controls panel and when you go there you're going to see turbulent displays has been applied. Now this is quite a displacement so to speak so I'm going to just go ahead and pull it down to say 35 because that's a bit too much in my opinion. Okay, good. So now we've warped the text but it is not animated. It is not waving or warping or wiggling or flagging or whatever you want to call it. So you can go ahead and adjust the type of displacement. Just note I'll show you a few examples, bulge, twist, etc. For this tutorial we'll just go with turbulent but I just want you to be aware that there are other types of warping. What we want to do now is we want to go down to the evolution and this is the one that you want to click on. Make sure that your playhead is at the beginning left click on evolution and you're going to notice that it's set to zero. Now you want to go all the way to the end of the video right there and go back a step here and you want to increase the evolution considerably. So I'm going to increase it to you know what let's do let's do five evolutions. It's a bit more than I would normally do but I'm going to have five rotations. So here we go. We're going to get up to five. There we go. Perfect. So let's take a look at what we've got now. I'm going to go back to the beginning and I'm going to hit the space bar and you'll see here that we have the text waving or displacing or wiggling and that is how you create wiggle. I will show you one more thing. You'll see here that in the effect controls panel that we have turbulent displace you can actually go to edit and then go edit copy and then I'm going to go to the image which is my second on the second video track and I'm going to go to edit play edit paste pardon me not please I'm thinking of photoshop here edit paste and now look the displacement or the wiggle is applied to both the text and the image guys that's it thanks for watching I'll be back soon with some more tutorials


Freedom! Today I want to talk to you about something that's not Pokemon Go. I want to talk to you about the YouTube Boot Camp. Now this one in particular is the Production Skills Boot Camp. Now I've seen a lot of channels. I've seen a lot of channels within the Freedom family. And one of the biggest things that I see is the lack of production value. Now a lot of people put a lot of heart and soul into their videos. However, sometimes the difference between an okay video and a stellar video are sometimes the small details. Things like lighting and, you know, camera perspective and things like that. Now this is not just for non-gamers. Like I've actually got a few testimonials here, or maybe here, I think here. We've got testimonials from some of our community team and staff showing that they found a lot of value in having done this even though they themselves run gaming channels. I do suggest that you sign up for this because this is vitally important for the future of your channel. Education or in educating yourself on your craft is one of the biggest and best things you can do to make sure that you keep your audience around. Of course outside of that is entertainment value, which we'll get into later. Now one of the big reasons I want you to do this right here, right now, is that Freedom is working on something called Freedom Academy which has a new iteration coming out here soon so that we're going to ourselves up our production value and some other things.  So go ahead, sign up. And one of the other great parts about this is that it allows you to be part of a community, an in-crowd who has done this. So let us know in the comment section down below if you've taken this, if you've got your certificate, if you've got your shiny certificate, tweet it at me at Anthony Smith. If you tweet it at me and I get enough of these, maybe just maybe I might feature them on a future episode because I don't know, I like featuring creators who look out for themselves and others, of course, but look out for number one, take the courses and I'll see if I can feature as many of you as I can find. Anyway, I'll go ahead and leave it there. Till next time, don't forget to like, subscribe and do all those things. It doesn't make us love our jobs. Also, be awesome to yourself and amazing to each other. Bye food and family.


Okay, welcome back. It's Jeff Frick from Silicon Angle. We had a nice little morning here at Accelerator Mountain View, California around the launch of their enterprise platform and really mobile first. And as we've seen time and time again with the big themes that are happening in the enterprise space now, right? Mobility, social, cloud, as well as big data. Accelerator's been on the edge of that for a while, really more in the consumer space, but is now really making a heavy-duty play into the enterprise space. And what we learned today is that mobility first and really embracing the transformational opportunity that mobility provides you is pretty powerful. We've heard from Jeff, the CEO, and Nolan, the CTO, both the co-founders, and of course my buddy, Camille Gran, who left Sandhill Road to come down to Mountain View to join this opportunity because he really thinks it's one of those major transformational opportunities for people to really rethink their business, rethink their business process using mobile both because of the way the data is consumed, but also the fact that we're all carrying around these unbelievably powerful sensors that are out in the field in the environment, collecting data that here to four couldn't really be easily collected. So great opportunity, a great story here at Accelerator. It'll be interesting to see how they play it out and kind of lead this mobile first generation. So thanks for coming by SiliconANGLE. I'm Jeff Frick, we go out to the events that you want to go to, we talk to the people that you want to talk to, the smartest people we can find, we ask the questions that we know you'd like to ask them if you were here and get you the answers that you want to know. So everything's available on siliconangle.com, our partner site, wikibon.org. Look forward to talking to you next time. Jeff Frick, SiliconANGLE, signing out from Mountain View. Bye-bye.