Re: [zathura] [Zathura PATCH] RFC
On Tue, Apr 02, 2013 at 09:45:44PM +0200, Sebastian Ramacher wrote: > On 2013-03-25 04:14:25, Marwan Tanager wrote: > > > Also, I remember, that I hit a mem-leak recently when working on a > > > poster made with LaTeX. I was recompiling the same page over and over > > > again with LaTeX and I the memory consumption went very high. I was > > > wondering if this is because zathura was remembering the pages from the > > > previous versions of the recompiled document. Maybe zathura should free > > > memory on document reloads? > > > > Yes, this is an actual bug that is reported at > > http://bugs.pwmt.org/issue274 > > and it should be fixed. Maybe you're the one who reported it! > > Everything except the file monitor and the zathura_t instance should be > released > and re-created (if I remember that correctly), i.e. the document gets closed > and > re-opened again. zathura is just a PITA to run with valgrind. There are so > many > GTK related errors, that we can't fix, that valgrind's output is pretty much > useless. > > We might have missed a free, g_object_unref, etc. somewhere of course. So > ideas to find memory leaks without valgrind or a use-able suppression file for > valgrind are very welcome. I had actually done a quick scan on the code as far as freeing the memory upon document closing is concerned, but wasn't able to spot anything missing. Everything seems to be freed, the poppler pages, the widgets, the cairo surfaces. But, of course, I'm not omniscient, and I could have missed something, too. While thinking about this issue, I got an idea that might be related; could this memory be allocated to the "target" surfaces of the widgets (i.e., the targets of the cairo contexts that are passed to zathura_page_widget_draw), as opposed to the source surfaces stored in zathura_page_widget_private_s that are used to draw on those targets, and which now seem to be freed when the cache entries are invalidated? Now, with a reasonable cache size, the rate of memory consumption is much less than it was before, which confirms that the source surfaces are actually freed. But, if memory is allocated only to the source surfaces, then the memory consumption should stay fixed as soon as ${page-cache-size} pages hit the screen. But, this is not what actually happens, and the memory consumption keeps increasing until each page in the document is viewed at least once. At this point, no more memory is consumed while scrolling. This makes me think that if the seemingly leaking memory is allocated to the target surfaces of the widgets, and GTK doesn't free this memory when freeing the widgets, then this might explain all of the above issues (creeping memory while scrolling, and after document reloads), and unfortunately, in this case, I think we wouldn't be able to do much about it. So, I hope I'm wrong ;) -- Marwan Tanager ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On 2013-04-02 21:45:44, Sebastian Ramacher wrote: > > > Also, I thought a while ago, that zathura's rendering experience could > > > be even further enhanced by caching the pages, which have not been seen > > > yet. For example at one moment we see a row of pages and zathura caches > > > the row above and below the one we currently view. Then if we scroll in > > > either direction, the page is already rendered, which might be visually > > > more pleasing than waiting for a large page to come up. Of course, this > > > should be implemented in such a way, that we do not recache the pages, > > > which are already among the ones which have been looked at recently. > > > > That's exactly what I've just been thinking about, simply a sliding window > > of a > > configurable number of rows centered at the current visible one and moving > > with > > us as we scroll around. > > > > Combined with the above caching, then pages outside of this window > > shouldn't be > > freed unless they 1) aren't in the cache, or 2) are in the cache, but need > > to > > be invalidated in order to make room for the currently visible ones if they > > aren't already in the cache. > > That'd be nice to have. Instead of a configurable number of rows we'd need > something that also loads pages left and right of the current page if > pages-per-row is larger than 1. JFTR: that's http://bugs.pwmt.org/issue267. -- Sebastian Ramacher signature.asc Description: Digital signature ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On 2013-03-25 04:14:25, Marwan Tanager wrote: > > Also, I remember, that I hit a mem-leak recently when working on a > > poster made with LaTeX. I was recompiling the same page over and over > > again with LaTeX and I the memory consumption went very high. I was > > wondering if this is because zathura was remembering the pages from the > > previous versions of the recompiled document. Maybe zathura should free > > memory on document reloads? > > Yes, this is an actual bug that is reported at http://bugs.pwmt.org/issue274 > and it should be fixed. Maybe you're the one who reported it! Everything except the file monitor and the zathura_t instance should be released and re-created (if I remember that correctly), i.e. the document gets closed and re-opened again. zathura is just a PITA to run with valgrind. There are so many GTK related errors, that we can't fix, that valgrind's output is pretty much useless. We might have missed a free, g_object_unref, etc. somewhere of course. So ideas to find memory leaks without valgrind or a use-able suppression file for valgrind are very welcome. > > Also, I thought a while ago, that zathura's rendering experience could > > be even further enhanced by caching the pages, which have not been seen > > yet. For example at one moment we see a row of pages and zathura caches > > the row above and below the one we currently view. Then if we scroll in > > either direction, the page is already rendered, which might be visually > > more pleasing than waiting for a large page to come up. Of course, this > > should be implemented in such a way, that we do not recache the pages, > > which are already among the ones which have been looked at recently. > > That's exactly what I've just been thinking about, simply a sliding window of > a > configurable number of rows centered at the current visible one and moving > with > us as we scroll around. > > Combined with the above caching, then pages outside of this window shouldn't > be > freed unless they 1) aren't in the cache, or 2) are in the cache, but need to > be invalidated in order to make room for the currently visible ones if they > aren't already in the cache. That'd be nice to have. Instead of a configurable number of rows we'd need something that also loads pages left and right of the current page if pages-per-row is larger than 1. Regards -- Sebastian Ramacher signature.asc Description: Digital signature ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On Mon, Mar 25, 2013 at 04:09:45AM +0100, Sebastian Ramacher wrote: > On 2013-03-25 04:59:58, Marwan Tanager wrote: > > On Mon, Mar 25, 2013 at 03:53:06AM +0100, Sebastian Ramacher wrote: > > > On 2013-03-24 07:28:03, Marwan Tanager wrote: > > > > While browsing the bug tracker for related issues, I found the one at > > > > http://bugs.pwmt.org/issue95 which points out the 0.0.8.5 version as > > > > not > > > > suffering from this problem. I built it and experimented. The result > > > > was that > > > > the total amount of memory consumed by scrolling through the length of > > > > the > > > > 1300-pages document was comparable to the one with this patch. So, > > > > there must > > > > be something messy happening with cairo_surface_destroy when it's get > > > > called > > > > from the timeout function while scrolling. Maybe it's non-reentrant and > > > > some > > > > mess happens when it's called concurrently from both the timeout > > > > function and > > > > the render thread. But if that's the case, then why doesn't it free > > > > the memory > > > > after the first time, even when there is no scrolling? Also, I tried to > > > > experiment with mutexes around the cairo_surface_destroy calls on the > > > > render > > > > thread and zathura_page_widget_update_surface but nothing surprising > > > > has > > > > happened. > > > > > > I played a bit with the code tonight. What puzzles me is that it works > > > for the first time but not for any subsequent purge operations. As far > > > as I can tell, the ref counters of the surface are 1 and thus > > > cairo_surface_destroy should free the image. cairo_surface_destroy is > > > definitely called, but I really don't know why nothing happens [1]. > > > > I've done exactly the same test and made sure the ref count is always 1 > > before > > the call. That's exactly what drove me nuts! > > Yes, it's totally weird. > > One further note: With the ps plugin the behavior is totally different > as far as I can tell. I've just tried with two document, one postscript and the other djvu. On my side, things seem to work well with djvu, but are still buggy with postscript. Marwan ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On 2013-03-25 04:59:58, Marwan Tanager wrote: > On Mon, Mar 25, 2013 at 03:53:06AM +0100, Sebastian Ramacher wrote: > > On 2013-03-24 07:28:03, Marwan Tanager wrote: > > > While browsing the bug tracker for related issues, I found the one at > > > http://bugs.pwmt.org/issue95 which points out the 0.0.8.5 version as not > > > suffering from this problem. I built it and experimented. The result was > > > that > > > the total amount of memory consumed by scrolling through the length of > > > the > > > 1300-pages document was comparable to the one with this patch. So, there > > > must > > > be something messy happening with cairo_surface_destroy when it's get > > > called > > > from the timeout function while scrolling. Maybe it's non-reentrant and > > > some > > > mess happens when it's called concurrently from both the timeout function > > > and > > > the render thread. But if that's the case, then why doesn't it free the > > > memory > > > after the first time, even when there is no scrolling? Also, I tried to > > > experiment with mutexes around the cairo_surface_destroy calls on the > > > render > > > thread and zathura_page_widget_update_surface but nothing surprising has > > > happened. > > > > I played a bit with the code tonight. What puzzles me is that it works > > for the first time but not for any subsequent purge operations. As far > > as I can tell, the ref counters of the surface are 1 and thus > > cairo_surface_destroy should free the image. cairo_surface_destroy is > > definitely called, but I really don't know why nothing happens [1]. > > I've done exactly the same test and made sure the ref count is always 1 > before > the call. That's exactly what drove me nuts! Yes, it's totally weird. One further note: With the ps plugin the behavior is totally different as far as I can tell. Regards -- Sebastian Ramacher ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On Mon, Mar 25, 2013 at 03:53:06AM +0100, Sebastian Ramacher wrote: > On 2013-03-24 07:28:03, Marwan Tanager wrote: > > While browsing the bug tracker for related issues, I found the one at > > http://bugs.pwmt.org/issue95 which points out the 0.0.8.5 version as not > > suffering from this problem. I built it and experimented. The result was > > that > > the total amount of memory consumed by scrolling through the length of the > > 1300-pages document was comparable to the one with this patch. So, there > > must > > be something messy happening with cairo_surface_destroy when it's get > > called > > from the timeout function while scrolling. Maybe it's non-reentrant and > > some > > mess happens when it's called concurrently from both the timeout function > > and > > the render thread. But if that's the case, then why doesn't it free the > > memory > > after the first time, even when there is no scrolling? Also, I tried to > > experiment with mutexes around the cairo_surface_destroy calls on the > > render > > thread and zathura_page_widget_update_surface but nothing surprising has > > happened. > > I played a bit with the code tonight. What puzzles me is that it works > for the first time but not for any subsequent purge operations. As far > as I can tell, the ref counters of the surface are 1 and thus > cairo_surface_destroy should free the image. cairo_surface_destroy is > definitely called, but I really don't know why nothing happens [1]. I've done exactly the same test and made sure the ref count is always 1 before the call. That's exactly what drove me nuts! Marwan ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On 2013-03-24 07:28:03, Marwan Tanager wrote: > While browsing the bug tracker for related issues, I found the one at > http://bugs.pwmt.org/issue95 which points out the 0.0.8.5 version as not > suffering from this problem. I built it and experimented. The result was that > the total amount of memory consumed by scrolling through the length of the > 1300-pages document was comparable to the one with this patch. So, there must > be something messy happening with cairo_surface_destroy when it's get called > from the timeout function while scrolling. Maybe it's non-reentrant and some > mess happens when it's called concurrently from both the timeout function and > the render thread. But if that's the case, then why doesn't it free the > memory > after the first time, even when there is no scrolling? Also, I tried to > experiment with mutexes around the cairo_surface_destroy calls on the render > thread and zathura_page_widget_update_surface but nothing surprising has > happened. I played a bit with the code tonight. What puzzles me is that it works for the first time but not for any subsequent purge operations. As far as I can tell, the ref counters of the surface are 1 and thus cairo_surface_destroy should free the image. cairo_surface_destroy is definitely called, but I really don't know why nothing happens [1]. I played with some gdk_threads_{enter,leave} calls around the destroy to no avail. I will follow up to the other mails in this thread later this week. [1] Nothing in the sense of that the first call gives a huge decrease in RES usage and subsequent calls only a small decrease. -- Sebastian Ramacher ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On Sun, Mar 24, 2013 at 11:49:23PM +, Ignas Anikevičius wrote: > Hello, > > On 24/03/13 03:34:33 +0100, Sebastian Ramacher wrote: > > ... > > > > The code to destroy the cairo surfaces periodically is not optimal, but > > if it all, we should fix this portion of the code. Maybe a timing-based > > solution is not a good idea and there are better ways to approach this, > > but I really don't want to ruin the above use case again. > > > > Ideas and patches to improve the page reclaiming code are very welcome. > > > > ... > > I was thinking about this and thought, that maybe a combination of two > approaches could be possible. I'll try to depict what I have in mind: > > - Load zathura and render the pages (i.e. keep them in memory), > which are visible. > > - When scrolling, remember all the pages seen in the last, say, 5 > minutes. > > - If we scroll through many pages, then it means that we are not > interested in viewing all of the pages, which we have seen in the > last 5 minutes. Then remember only the last 10 pages. > > So in essence, what I propose, is to keep a page buffer which would > remember all pages from last 5 minutes or last 10 pages whichever is > smaller. Of course the quantities here are taken only for illustrative > purposes and I have no idea whether they make sense or not. As far as I understand from this, you're talking about a cache of configurable size (in number of pages), that are invalidated using a LRU algorithm. If that's the case, then I like your idea, and think that it would be effective here. > Also, I remember, that I hit a mem-leak recently when working on a > poster made with LaTeX. I was recompiling the same page over and over > again with LaTeX and I the memory consumption went very high. I was > wondering if this is because zathura was remembering the pages from the > previous versions of the recompiled document. Maybe zathura should free > memory on document reloads? Yes, this is an actual bug that is reported at http://bugs.pwmt.org/issue274 and it should be fixed. Maybe you're the one who reported it! > Also, I thought a while ago, that zathura's rendering experience could > be even further enhanced by caching the pages, which have not been seen > yet. For example at one moment we see a row of pages and zathura caches > the row above and below the one we currently view. Then if we scroll in > either direction, the page is already rendered, which might be visually > more pleasing than waiting for a large page to come up. Of course, this > should be implemented in such a way, that we do not recache the pages, > which are already among the ones which have been looked at recently. That's exactly what I've just been thinking about, simply a sliding window of a configurable number of rows centered at the current visible one and moving with us as we scroll around. Combined with the above caching, then pages outside of this window shouldn't be freed unless they 1) aren't in the cache, or 2) are in the cache, but need to be invalidated in order to make room for the currently visible ones if they aren't already in the cache. > Let me know if I made the explanation clear enough and if something > similar would be desired in zathura. I think we're yet to see what Sebastian (and maybe others) think of this. I was just expressing my opinion. Marwan ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
Hello, On 24/03/13 03:34:33 +0100, Sebastian Ramacher wrote: > ... > > The code to destroy the cairo surfaces periodically is not optimal, but > if it all, we should fix this portion of the code. Maybe a timing-based > solution is not a good idea and there are better ways to approach this, > but I really don't want to ruin the above use case again. > > Ideas and patches to improve the page reclaiming code are very welcome. > > ... I was thinking about this and thought, that maybe a combination of two approaches could be possible. I'll try to depict what I have in mind: - Load zathura and render the pages (i.e. keep them in memory), which are visible. - When scrolling, remember all the pages seen in the last, say, 5 minutes. - If we scroll through many pages, then it means that we are not interested in viewing all of the pages, which we have seen in the last 5 minutes. Then remember only the last 10 pages. So in essence, what I propose, is to keep a page buffer which would remember all pages from last 5 minutes or last 10 pages whichever is smaller. Of course the quantities here are taken only for illustrative purposes and I have no idea whether they make sense or not. Also, I remember, that I hit a mem-leak recently when working on a poster made with LaTeX. I was recompiling the same page over and over again with LaTeX and I the memory consumption went very high. I was wondering if this is because zathura was remembering the pages from the previous versions of the recompiled document. Maybe zathura should free memory on document reloads? Also, I thought a while ago, that zathura's rendering experience could be even further enhanced by caching the pages, which have not been seen yet. For example at one moment we see a row of pages and zathura caches the row above and below the one we currently view. Then if we scroll in either direction, the page is already rendered, which might be visually more pleasing than waiting for a large page to come up. Of course, this should be implemented in such a way, that we do not recache the pages, which are already among the ones which have been looked at recently. Let me know if I made the explanation clear enough and if something similar would be desired in zathura. All the best, Ignas ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On Sun, Mar 24, 2013 at 03:34:33PM +0100, Sebastian Ramacher wrote: > On 2013-03-24 07:28:03, Marwan Tanager wrote: > > This patch tries to solve a serious problem with zathura leaking a > > horrendous > > amount of memory during scrolling through a document. > > > > The problem is that the current way of periodically reclaiming the cairo > > surfaces of the pages widgets is not working at all. The only case in which > > it > > seems to work is the first time (and "only" the first time) the timeout > > function purge_pages is triggered, and even this first time sometimes > > doesn't > > free the memory if it happened while scrolling through the document. > > > > To see it in action, try opening a large document (e.g. 500+ pages), and > > scroll through it by dragging the scrollbar or continuously pressing > > , > > or . Meanwhile, watch the output of 'top $(pidof zathura)' until > > you > > end up with a throttled system riddled with continuous swapping. Zathura > > will > > fiercely eat all the physical system memory while scrolling through a > > relatively big document. > > > > I've spent a while trying to figure out why the memory isn't freed after > > the > > first time the timeout function is triggered, but quite frankly, I couldn't > > manage to get to any reasonable conclusion. Injecting debug messages in > > zathura_page_widget_update_surface shows that all the pages, but the > > current > > visible one, are eventually reclaimed. This means that > > cairo_surface_destroy > > must have been called on every surface of a page that exceeded it's > > end-of-life > > threshold, but without actually doing it's job of freeing the surface > > memory. > > > > So, this patch bypasses this mechanism by freeing a surface as soon as it's > > associated page becomes invisible. Try repeating the same experiment as > > above > > with this patch, and watch the rate of memory consumption drops > > dramatically. I > > scrolled the entire length of a 1300-pages document and the end result was > > 500 > > MB. And I don't think this is leaking memory due to cairo surfaces pixel > > buffers, because it never increases after reaching this limit. Maybe it's > > some > > internal allocations done by GTK or GDK. This doesn't seem very far-fetched > > for > > an application with 1300+ GTK widgets in this case. > > No, please don't. There is reason why we decided to keep the pages in > memory: consider a document with same pages, but one of them takes ages > to render ([1] has an extreme example of such a file, but any document > with larger images should do). In 0.0.8.x scrolling was a PITA with such > documents: you had to wait until the page was fully rendered to do > anything else. Personally, I haven't had an encounter with such extreme cases, so I hadn't thought of this, but of course this is something that should be considered. > Keeping the pages in memory for some time is our attempt to improve the > scrolling experience in that case. Scrolling back and forth between two > pages becomes a much better experience since you don't have to wait > until the page is re-rendered to see it. So it's a compromise between > memory usage and time spent to re-render pages. Of course, it's an obvious trade-off, but when it is very unbalanced like in this case (I don't want to sacrifice all of my system memory and crash running applications in order to have a good experience scrolling around a pdf document), that's where we should reconsider doing things. > The code to destroy the cairo surfaces periodically is not optimal, but > if it all, we should fix this portion of the code. Maybe a timing-based > solution is not a good idea and there are better ways to approach this, > but I really don't want to ruin the above use case again. > > Ideas and patches to improve the page reclaiming code are very welcome. That's why I sent the patch in the first place. I didn't actually intend it to be applied, but just to shed some light on the source of the problem. Marwan ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
Re: [zathura] [Zathura PATCH] RFC
On 2013-03-24 07:28:03, Marwan Tanager wrote: > This patch tries to solve a serious problem with zathura leaking a horrendous > amount of memory during scrolling through a document. > > The problem is that the current way of periodically reclaiming the cairo > surfaces of the pages widgets is not working at all. The only case in which > it > seems to work is the first time (and "only" the first time) the timeout > function purge_pages is triggered, and even this first time sometimes doesn't > free the memory if it happened while scrolling through the document. > > To see it in action, try opening a large document (e.g. 500+ pages), and > scroll through it by dragging the scrollbar or continuously pressing > , > or . Meanwhile, watch the output of 'top $(pidof zathura)' until you > end up with a throttled system riddled with continuous swapping. Zathura will > fiercely eat all the physical system memory while scrolling through a > relatively big document. > > I've spent a while trying to figure out why the memory isn't freed after the > first time the timeout function is triggered, but quite frankly, I couldn't > manage to get to any reasonable conclusion. Injecting debug messages in > zathura_page_widget_update_surface shows that all the pages, but the current > visible one, are eventually reclaimed. This means that cairo_surface_destroy > must have been called on every surface of a page that exceeded it's > end-of-life > threshold, but without actually doing it's job of freeing the surface memory. > > So, this patch bypasses this mechanism by freeing a surface as soon as it's > associated page becomes invisible. Try repeating the same experiment as above > with this patch, and watch the rate of memory consumption drops dramatically. > I > scrolled the entire length of a 1300-pages document and the end result was > 500 > MB. And I don't think this is leaking memory due to cairo surfaces pixel > buffers, because it never increases after reaching this limit. Maybe it's > some > internal allocations done by GTK or GDK. This doesn't seem very far-fetched > for > an application with 1300+ GTK widgets in this case. No, please don't. There is reason why we decided to keep the pages in memory: consider a document with same pages, but one of them takes ages to render ([1] has an extreme example of such a file, but any document with larger images should do). In 0.0.8.x scrolling was a PITA with such documents: you had to wait until the page was fully rendered to do anything else. Keeping the pages in memory for some time is our attempt to improve the scrolling experience in that case. Scrolling back and forth between two pages becomes a much better experience since you don't have to wait until the page is re-rendered to see it. So it's a compromise between memory usage and time spent to re-render pages. The code to destroy the cairo surfaces periodically is not optimal, but if it all, we should fix this portion of the code. Maybe a timing-based solution is not a good idea and there are better ways to approach this, but I really don't want to ruin the above use case again. Ideas and patches to improve the page reclaiming code are very welcome. Cheers -- Sebastian Ramacher ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura
[zathura] [Zathura PATCH] RFC
This patch tries to solve a serious problem with zathura leaking a horrendous amount of memory during scrolling through a document. The problem is that the current way of periodically reclaiming the cairo surfaces of the pages widgets is not working at all. The only case in which it seems to work is the first time (and "only" the first time) the timeout function purge_pages is triggered, and even this first time sometimes doesn't free the memory if it happened while scrolling through the document. To see it in action, try opening a large document (e.g. 500+ pages), and scroll through it by dragging the scrollbar or continuously pressing , or . Meanwhile, watch the output of 'top $(pidof zathura)' until you end up with a throttled system riddled with continuous swapping. Zathura will fiercely eat all the physical system memory while scrolling through a relatively big document. I've spent a while trying to figure out why the memory isn't freed after the first time the timeout function is triggered, but quite frankly, I couldn't manage to get to any reasonable conclusion. Injecting debug messages in zathura_page_widget_update_surface shows that all the pages, but the current visible one, are eventually reclaimed. This means that cairo_surface_destroy must have been called on every surface of a page that exceeded it's end-of-life threshold, but without actually doing it's job of freeing the surface memory. So, this patch bypasses this mechanism by freeing a surface as soon as it's associated page becomes invisible. Try repeating the same experiment as above with this patch, and watch the rate of memory consumption drops dramatically. I scrolled the entire length of a 1300-pages document and the end result was 500 MB. And I don't think this is leaking memory due to cairo surfaces pixel buffers, because it never increases after reaching this limit. Maybe it's some internal allocations done by GTK or GDK. This doesn't seem very far-fetched for an application with 1300+ GTK widgets in this case. While browsing the bug tracker for related issues, I found the one at http://bugs.pwmt.org/issue95 which points out the 0.0.8.5 version as not suffering from this problem. I built it and experimented. The result was that the total amount of memory consumed by scrolling through the length of the 1300-pages document was comparable to the one with this patch. So, there must be something messy happening with cairo_surface_destroy when it's get called from the timeout function while scrolling. Maybe it's non-reentrant and some mess happens when it's called concurrently from both the timeout function and the render thread. But if that's the case, then why doesn't it free the memory after the first time, even when there is no scrolling? Also, I tried to experiment with mutexes around the cairo_surface_destroy calls on the render thread and zathura_page_widget_update_surface but nothing surprising has happened. So, what's your suggestions, ideas (or maybe patches :-))? And what's the final destiny of the periodic page reclaiming code? Marwan Tanager (1): Fix a horrible memory leak. callbacks.c |3 +++ page-widget.c |9 + page-widget.h |8 3 files changed, 20 insertions(+) -- 1.7.10.4 ___ zathura mailing list zathura@lists.pwmt.org http://lists.pwmt.org/mailman/listinfo/zathura