Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 24 Jan 2023 09:42:27 -0700 | Subject | Re: [PATCH] x86/fpu: don't set TIF_NEED_FPU_LOAD for PF_IO_WORKER threads | From | Jens Axboe <> |
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On 1/24/23 9:23 AM, Peter Zijlstra wrote: > On Tue, Jan 24, 2023 at 09:06:08AM -0700, Jens Axboe wrote: >> On 1/24/23 8:40 AM, Peter Zijlstra wrote: >>> On Tue, Jan 24, 2023 at 08:23:20AM -0700, Jens Axboe wrote: >>>> We don't set it on PF_KTHREAD threads as they never return to userspace, >>>> and PF_IO_WORKER threads are identical in that regard. As they keep >>>> running in the kernel until they die, skip setting the FPU flag on them. >>> >>> No objection to the actual patch; but this changelog fails to tell us >>> why this is important. >>> >>> What made you get up and write this patch :-) Presumably this is a >>> performance issue? If so, can you quantify how much? >> >> You snipped the part where that was explained, but arguably that should >> probably go into the commit message itself: >> >> "Not urgent, more of a cosmetic thing that was found while debugging and >> issue and pondering why the FPU flag is set on these threads." > > Duh, I stopped reading at the --- just like a patch tool.. :/
Yeah... Half of that should've been in the commit message, my bad.
>> So it's not really a performance issue, it was just something odd that >> got me scratching my head when debugging another issue and poking at >> the flags. >> >> Want a resend of it, or will you just augment the commit message? > > I think tglx typically takes fpu patches, but sure can do.
Thanks!
-- Jens Axboe
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