From: Peter Zijlstra <peterz@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>,
the arch/x86 maintainers <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/fpu: don't set TIF_NEED_FPU_LOAD for PF_IO_WORKER threads
Date: Tue, 24 Jan 2023 16:40:56 +0100 [thread overview]
Message-ID: <Y8/8CFwtpmjzdK9c@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <560c844c-f128-555b-40c6-31baff27537f@kernel.dk>
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?
next prev parent reply other threads:[~2023-01-24 15:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 15:23 [PATCH] x86/fpu: don't set TIF_NEED_FPU_LOAD for PF_IO_WORKER threads Jens Axboe
2023-01-24 15:40 ` Peter Zijlstra [this message]
2023-01-24 16:06 ` Jens Axboe
2023-01-24 16:23 ` Peter Zijlstra
2023-01-24 16:42 ` Jens Axboe
2023-01-25 11:39 ` [tip: x86/fpu] x86/fpu: Don't " tip-bot2 for Jens Axboe
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