On Fri, 05 Feb 2016 03:40:46 +0100 Mike Galbraith <umgwanakikbuti@xxxxxxxxx> wrote: > On Thu, 2016-02-04 at 17:39 +0100, Daniel Bilik wrote: > > On Thu, 4 Feb 2016 12:20:44 +0100 > > Jan Kara <jack@xxxxxxx> wrote: > > > > > Thanks for backport Thomas and to Mike for persistence :). I've > > > asked my friend seeing crashes with 3.18.25 to try whether this > > > patch fixes the issues. It may take some time so stay tuned... > > > > Patch tested and it really fixes the crash we were experiencing on > > 3.18.25 with commit 874bbfe+. But it seem to introduce (rather scary) > > regression. Tested host shows abnormal cpu usage in both kernel and > > userland under the same load and traffic pattern. One picture is worth > > a thousand words, so I've taken snapshots of our graphs, see here: > > http://neosystem.cz/test/linux-3.18.25/ > > The host was running 3.18.25 with commit 874bbfe+ (1e7af29+ on > > 3.18-stable) reverted. With this commit included, it crashed within > > minutes. Around 13:30 we booted 3.18.25 with commit 874bbfe+ included > > and with the patch from Thomas. And around 15:40 we've booted the host > > with previous kernel, just to ensure this abnormal behaviour was > > really caused by the test kernel. > > Also interesting, in addition to high cpu usage, there is abnormally > > high number of zombie processes reported by the system. > > IMHO you should restore the CC list and re-post. (If I were the > maintainer of either the workqueue code or 3.18-stable, I'd be highly > interested in this finding). Sorry, I haven't realized tha patch proposed by Thomas is already on its way to stable. CC restored and re-posting. -- Daniel Bilik neosystem.cz -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html