Re: [PATCH 13/12] ksm: fix munlock during exit_mmap deadlock

From: David Rientjes
Date: Wed Aug 26 2009 - 18:00:28 EST


On Wed, 26 Aug 2009, Andrea Arcangeli wrote:

> In oom deadlock terms madvise(UNMERGEABLE) is the only place that is
> 100% fine at breaking KSM pages, because it runs with right tsk->mm
> and page allocation will notice TIF_MEMDIE set on tsk.
>

Be aware that the page allocator in Linus' git will not notice TIF_MEMDIE
for current if that task is chosen for oom kill since alloc_flags are not
updated for that particular allocation. My patch in -mm,
mm-update-alloc_flags-after-oom-killer-has-been-called.patch, fixes that
but is not yet merged (I assume it's on hold for 2.6.32?).

I'd hate for you to run into this in testing and spend time debugging it
when the problem already has a fix.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/