Messages in this thread | | | Date | Sun, 16 Mar 2014 20:43:18 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [Xen-devel] [PATCHv1] x86: don't schedule when handling #NM exception |
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On 03/16/2014 08:35 PM, Sarah Newman wrote: > Can you please review my patch first? It's only enabled when absolutely required.
It doesn't help. It means you're running on Xen, and you will have processes subjected to random SIGKILL because they happen to touch the FPU when the atomic pool is low.
However, there is probably a happy medium: you don't actually need eager FPU restore, you just need eager FPU *allocation*. We have been intending to allocate the FPU state at task creation time for eagerfpu, and Suresh Siddha has already produced such a patch; it just needs some minor fixups due to an __init failure.
http://lkml.kernel.org/r/1391325599.6481.5.camel@europa
In the Xen case we could turn on eager allocation but not eager fpu. In fact, it might be justified to *always* do eager allocation...
-hpa
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