Messages in this thread | | | Date | Mon, 17 Oct 2011 16:14:45 +1100 | From | David Gibson <> | Subject | Re: [PATCH v2 1/1] hugepages: Fix race between hugetlbfs umount and quota update. |
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On Fri, Oct 14, 2011 at 01:59:48PM -0700, Andrew Morton wrote: > On Wed, 12 Oct 2011 15:43:17 +1100 > Paul Mackerras <paulus@samba.org> wrote: > > > In the meantime we have a user-triggerable kernel crash. As far as I > > can see, if we did what you suggest, we would end up with a situation > > where we could run out of huge pages even though everyone was within > > quota. Which is arguably better than a kernel crash, but still less > > than ideal. What do you suggest? > > My issue with the patch is that it's rather horrible. We have a layer > of separation between core hugetlb pages and hugetlbfs. That layering > has already been mucked up in various places and this patch mucks it up > further, and quite severely. > > So I believe we should rethink the patch. Either a) get the layering > correct by not poking into hugetlbfs internals from within hugetlb core > via one of the usual techniques or
Which usual techniques did you have in mind?
> b) make a deliberate decision to > just give up on that layering: state that hugetlb and hugetlbfs are now > part of the same subsystem. Make the necessaary Kconfig changes, > remove ifdefs, move code around, etc.
Well, that might have something to be said for it, the distinction has always been tenuous at best.
> If we go ahead with the proposed patch-n-run bugfix, the bad code will > be there permanently - nobody will go in and clean this mess up and the > kernel is permanently worsened.
Hrm, as opposed to leaving the crash bug there until someone has time to do the requested cleanup.
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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