argh, sorry, I didn't finish my email... On 12/03, Sergey Dyasly wrote: > > On Mon, 2 Dec 2013 16:24:23 +0100 > Oleg Nesterov <o...@redhat.com> wrote: > > > Recently people started to report they actually hit this problem in > > oom_kill.c. This doesn't really matter and I can be wrong, but in > > fact I do not think they really hit this race, it is very unlikely. > > The race is very easy to catch if you have a process with several threads, > all of which allocates memory simultaneously. This leads to: > > 1) OOMk selects and sends SIGKILL to one of the threads > > 2) another thread invokes OOMk and the first thread gets selected, > but it gets unhashed before while_each_thread...
Yes, but this is what I meant. It was unhashed before even while_each_thread(g), and it should be never used unless you ensure that g is still alive. But this doesn't matter. while_each_thread() was buggy anyway. And (perhaps even more importantly) it was not easy to use it correctly, so I finally decided to add another helper which only needs the stable task_struct. > The patches look correct and my test case no longer hangs, so > > Reviewed-and-Tested-by: Sergey Dyasly <dse...@gmail.com> Thanks! Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
