From: David Laight <david.laight.linux@gmail.com>
To: Uros Bizjak <ubizjak@gmail.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH -tip] x86/locking/atomic: Use asm_inline for atomic locking insns
Date: Wed, 5 Mar 2025 22:18:06 +0000 [thread overview]
Message-ID: <20250305221806.7f25108f@pumpkin> (raw)
In-Reply-To: <CAFULd4YNvz2rJEJDjacCeWak-JZNUfMB5LuM+qAwn_DCcn-CUg@mail.gmail.com>
On Wed, 5 Mar 2025 20:47:46 +0100
Uros Bizjak <ubizjak@gmail.com> wrote:
...
> From the compiler POV, now that "lock; " prefix lost its semicolon,
> removing LOCK_PREFIX_HERE or using asm_inline would result in exactly
> the same code. The problematic 31k code size increase (1.1%) with -O2
> is inevitable either way, if we want to move forward.
Have you looked to see where that 31k comes from?
The compiler must be very near to inlining something and removing a couple
of instructions is making a big difference.
It is quite likely that some other change will have the same (or the reverse)
effect.
David
next prev parent reply other threads:[~2025-03-05 22:18 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-28 12:35 [PATCH -tip] x86/locking/atomic: Use asm_inline for atomic locking insns Uros Bizjak
2025-02-28 13:13 ` Uros Bizjak
2025-02-28 16:48 ` Dave Hansen
2025-02-28 22:31 ` Uros Bizjak
2025-02-28 22:58 ` Dave Hansen
2025-03-01 9:05 ` Uros Bizjak
2025-03-01 12:38 ` Borislav Petkov
2025-03-05 8:54 ` Uros Bizjak
2025-03-05 17:04 ` Linus Torvalds
2025-03-05 19:40 ` Peter Zijlstra
2025-03-05 19:47 ` Uros Bizjak
2025-03-05 22:18 ` David Laight [this message]
2025-03-05 20:14 ` David Laight
2025-03-06 10:45 ` Uros Bizjak
2025-03-06 13:07 ` Uros Bizjak
2025-03-06 22:19 ` Ingo Molnar
2025-03-08 7:22 ` Uros Bizjak
2025-03-08 19:15 ` H. Peter Anvin
2025-03-05 19:55 ` Ingo Molnar
2025-03-05 20:13 ` Uros Bizjak
2025-03-05 20:21 ` Ingo Molnar
2025-03-06 9:38 ` Uros Bizjak
2025-03-05 20:20 ` Ingo Molnar
2025-03-06 10:52 ` Dirk Gouders
2025-03-06 10:59 ` Ingo Molnar
2025-03-05 20:36 ` Borislav Petkov
2025-03-05 21:26 ` Peter Zijlstra
2025-03-06 9:01 ` Uros Bizjak
2025-03-06 9:43 ` kernel: Current status of CONFIG_CC_OPTIMIZE_FOR_SIZE=y (was: Re: [PATCH -tip] x86/locking/atomic: Use asm_inline for atomic locking insns) Ingo Molnar
2025-03-06 10:37 ` Arnd Bergmann
2025-03-06 20:37 ` David Laight
2025-03-03 13:12 ` [PATCH -tip] x86/locking/atomic: Use asm_inline for atomic locking insns David Laight
2025-03-02 20:56 ` Uros Bizjak
2025-03-03 12:23 ` Uros Bizjak
2025-03-08 19:08 ` H. Peter Anvin
2025-03-09 7:50 ` Uros Bizjak
2025-03-09 9:46 ` David Laight
2025-03-09 9:57 ` Uros Bizjak
2025-03-06 9:57 ` Ingo Molnar
2025-03-06 10:26 ` Uros Bizjak
2025-03-06 10:38 ` Ingo Molnar
2025-03-06 10:50 ` Ingo Molnar
2025-03-06 13:56 ` Uros Bizjak
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=20250305221806.7f25108f@pumpkin \
--to=david.laight.linux@gmail.com \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linuxfoundation.org \
--cc=ubizjak@gmail.com \
--cc=x86@kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.