On Wed, Dec 23, 2015 at 11:32:21AM -0500, Johannes Weiner wrote: > Hi Marcin, Hi, > On Wed, Dec 23, 2015 at 03:31:09PM +0100, Marcin Szewczyk wrote: > > In 2010 I noticed that viewing many GIFs in a row using gpicview renders > > my Linux unresponsive. The problem still exists. There is very little > > I can do in such a situation. Rarely after some minutes the OOM killer > > kicks in and saves the day. Nevertheless, usually I end up using > > Alt+SysRq+B. > > Have you tried kicking the OOM killer manually with sysrq+f? I completely forgot about that option. It works both at TTY and under Xorg. Thank you very much. > > The unresponsiveness goes with high CPU load and a lot of IO (read) > > operations on the root file system and its block device. > > There is a semi-known issue of heavily thrashing page cache. Your > crash program sucks up most memory and leaves very little for the > executables and libraries to be cached, which results in multiple > threads experiencing cache misses in their executable code, followed > by fighting over the few remaining page cache slots, which are not > enough to meet the demand at any given point in time. [...] Thank you for the explanation. > That being said, there is no real solution to thrashing page cache as > of this day. We have most infrastructure in place to detect it, but it > isn't hooked up to the OOM killer yet. The only answer until then is > try to keep free+buffer+cache at at least 10-15% of overall memory. OK. Is there a good source of information I could subscribe to so I don't miss the moment when the integration code enters the kernel? Do you think LWN would mention it or should I just follow "oom" messages on linux-kernel and linux-mm? > Since you can reproduce it easily, is there any chance you could grab > backtraces (sysrq+t) of the tasks while the machine is in that state? > That should confirm that most tasks are either waiting for IO or are > inside page reclaim. I've updated the repository. I will later add this thread to the README. Dump is available here: https://github.com/wodny/crasher/blob/master/logs/kern.log I didn't want to post 200kB to everybody so I didn't attach it to this email. -- Marcin Szewczyk http://wodny.org mailto:Marcin.Szewczyk@xxxxxxxxxx <- remove b / usuń b xmpp:wodny@xxxxxxxxx xmpp:wodny@xxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>