From: Will Deacon <will@kernel.org>
To: Li Qiang <liqiang01@kylinos.cn>
Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: add unlikely hint to MTE async fault check in el0_svc_common
Date: Mon, 22 Sep 2025 11:59:26 +0100 [thread overview]
Message-ID: <aNEsDswLSpBkf-5S@willie-the-truck> (raw)
In-Reply-To: <20250919033327.1942730-1-liqiang01@kylinos.cn>
On Fri, Sep 19, 2025 at 11:33:27AM +0800, Li Qiang wrote:
> Add unlikely() hint to the _TIF_MTE_ASYNC_FAULT flag check in
> el0_svc_common() since asynchronous MTE faults are expected to be
> rare occurrences during normal system call execution.
>
> This optimization helps the compiler to improve instruction caching
> and branch prediction for the common case where no asynchronous
> MTE faults are pending, while maintaining correct behavior for
> the exceptional case where such faults need to be handled prior
> to system call execution.
>
> Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
> ---
> arch/arm64/kernel/syscall.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Does this result in a measurable performance difference?
Will
next prev parent reply other threads:[~2025-09-22 10:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-19 3:33 [PATCH] arm64: add unlikely hint to MTE async fault check in el0_svc_common Li Qiang
2025-09-22 10:59 ` Will Deacon [this message]
2025-09-28 9:01 ` Li Qiang
2025-11-11 20:17 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aNEsDswLSpBkf-5S@willie-the-truck \
--to=will@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liqiang01@kylinos.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox