Messages in this thread | | | Date | Tue, 14 Oct 2014 11:31:05 -0400 | From | Rik van Riel <> | Subject | Re: [BUG] mm, thp: khugepaged can't allocate on requested node when confined to a cpuset |
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On 10/14/2014 10:54 AM, Peter Zijlstra wrote: > On Tue, Oct 14, 2014 at 02:48:28PM +0300, Kirill A. Shutemov wrote: > >> Why whould you want to pin khugpeaged? Is there a valid use-case? >> Looks like userspace shoots to its leg. > > Its just bad design to put so much work in another context. But the > use-case is isolating other cpus. > >> Is there a reason why we should respect cpuset limitation for kernel >> threads? > > Yes, because we want to allow isolating CPUs from 'random' activity. > >> Should we bypass cpuset for PF_KTHREAD completely? > > No. That'll break stuff.
Agreed on the above.
I suspect the sane thing to do is allow a cpuset limited task to still allocate pages elsewhere, if it explicitly asks for it.
Ask for something potentially stupid? Get it :)
In many of the cases where something asks for memory in a specific location, it has a good reason to do so, and there's no reason to deny it.
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