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). -Mike -- 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