Bug#595711: linux-image-2.6.26-2-xen-686: Wrong free memory values for xen kernel with xenballoon use
В Пнд, 06/09/2010 в 07:59 +0100, Ian Campbell пишет:
> On Mon, 2010-09-06 at 04:03 +0400, George Shuklin wrote:
> >
> > I belive, this somehow related to difference in drivers/xen/balloon.c,
> > gentoo/SUSE version have some lines like
> >
> > totalram_pages--;
> > (in balloon_append() function)
> >
> > and
> > totalram_pages++;
> > (in balloon_retrieve() function)
> >
> > Those lines are in Gentoo kernel (linux-2.6.34-xen) but absent in
> > Debian (linux-image-2.6.26-2-xen-686)
>
> Is the Gentoo kernel pvops or classic-Xen patches?
>
> Are you sure you are using the classic-Xen
> (linux-image-...-xen-{686,amd}) kernel rather than the pvops one
> (linux-image-...-686-bigmem, no 64 bit pvops in Lenny)?
>
> I wasn't aware that it applied to the classic-Xen case but the
> difference you describe sounds like this commit from upstream pvops:
>
> http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=commit;h=3d65c9488cadd2f11bd4d60c7266e639ece5d0d6
>
> Probably for a 2.6.26 classic-Xen kernel you'd need to adjust the path
> to drivers/xen/balloon/balloon.c and perhaps tweak some context a bit
> but the concept should still apply.
Classic Xen (xen-686). pv_ops does not support preinflated ballooning
(maxmem >mem), so I stuck with classic xen.
I think, balloon code does not differ (principally) in pv_ops and
classic xen.
And, in any way, this bug exists. And it really suck: application ask
memory, one part of kernel (or libc?) thinking of free memory, kernel
found 'no memory left' and start OOM killer. It walking and killing some
random applications (include init).
I'm testing kernel with with patch right now and it seems work fine -
memory reporting correctly and oom kills only most bloated application
requesting tons of memory.
Ian.
>
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