From: David Laight <David.Laight@ACULAB.COM>
To: 'Segher Boessenkool' <segher@kernel.crashing.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>,
Andrew Cooper <Andrew.Cooper3@citrix.com>,
Nick Desaulniers <ndesaulniers@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Bill Wendling <morbo@google.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "Nathan Chancellor" <nathan@kernel.org>,
Juergen Gross <jgross@suse.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"llvm@lists.linux.dev" <llvm@lists.linux.dev>,
LKML <linux-kernel@vger.kernel.org>,
linux-toolchains <linux-toolchains@vger.kernel.org>
Subject: RE: [PATCH v5] x86: use builtins to read eflags
Date: Fri, 18 Mar 2022 22:36:48 +0000 [thread overview]
Message-ID: <ad0d80fdfb404df6a98c68e759fca199@AcuMS.aculab.com> (raw)
In-Reply-To: <20220318220901.GS614@gate.crashing.org>
From: Segher Boessenkool
> Sent: 18 March 2022 22:09
...
> It generally is a very good idea to
> have a redzone though, without it you pay much more than necessary for
> frame setup and teardown in leaf functions (similar to some of what the
> misnamed "shrink-wrapping" optimisation does, but the two are mostly
> independent, the benefits add up).
Are there really leaf functions that need to spill data to stack
where the cost of setting up a stack frame is significant?
I'd have thought that was relatively rare.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-03-18 22:36 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20211215211847.206208-1-morbo@google.com>
[not found] ` <87mtl1l63m.ffs@tglx>
2021-12-16 19:55 ` [PATCH] x86: use builtins to read eflags Bill Wendling
2021-12-17 12:48 ` Peter Zijlstra
2021-12-17 19:39 ` Thomas Gleixner
2022-03-14 23:09 ` H. Peter Anvin
2022-03-15 0:08 ` Bill Wendling
[not found] ` <20211215232605.GJ16608@worktop.programming.kicks-ass.net>
2021-12-16 20:00 ` Bill Wendling
2021-12-16 20:07 ` Nick Desaulniers
2021-12-29 2:12 ` [PATCH v2] " Bill Wendling
2022-01-27 20:56 ` Bill Wendling
2022-02-04 0:16 ` Thomas Gleixner
2022-02-04 0:58 ` Bill Wendling
2022-02-04 0:57 ` [PATCH v3] " Bill Wendling
2022-02-07 22:11 ` Nick Desaulniers
2022-02-08 9:14 ` David Laight
2022-02-08 23:18 ` Bill Wendling
2022-02-14 23:53 ` Nick Desaulniers
2022-02-10 22:31 ` [PATCH v4] " Bill Wendling
2022-02-11 16:40 ` David Laight
2022-02-11 19:25 ` Bill Wendling
2022-02-11 22:09 ` David Laight
2022-02-11 23:33 ` Bill Wendling
2022-02-12 0:24 ` Nick Desaulniers
2022-02-12 9:23 ` Bill Wendling
2022-02-15 0:33 ` Nick Desaulniers
2022-03-01 20:19 ` [PATCH v5] " Bill Wendling
2022-03-14 23:07 ` Bill Wendling
[not found] ` <AC3D873E-A28B-41F1-8BF4-2F6F37BCEEB4@zytor.com>
2022-03-15 7:19 ` Bill Wendling
2022-03-17 15:43 ` H. Peter Anvin
2022-03-17 18:00 ` Nick Desaulniers
2022-03-17 18:52 ` Linus Torvalds
2022-03-17 19:45 ` Bill Wendling
2022-03-17 20:13 ` Linus Torvalds
2022-03-17 21:10 ` Bill Wendling
2022-03-17 21:21 ` Linus Torvalds
2022-03-17 21:45 ` Bill Wendling
2022-03-17 22:51 ` Linus Torvalds
2022-03-17 23:14 ` Linus Torvalds
2022-03-17 23:19 ` Segher Boessenkool
2022-03-17 23:31 ` Linus Torvalds
2022-03-18 0:05 ` Segher Boessenkool
2022-03-17 22:37 ` Segher Boessenkool
2022-03-17 20:13 ` Florian Weimer
2022-03-17 20:36 ` Linus Torvalds
2022-03-18 0:25 ` Segher Boessenkool
2022-03-18 1:21 ` Linus Torvalds
2022-03-18 1:50 ` Linus Torvalds
2022-03-17 21:05 ` Andrew Cooper
2022-03-17 21:39 ` Linus Torvalds
2022-03-18 17:59 ` Andy Lutomirski
2022-03-18 18:19 ` Linus Torvalds
2022-03-18 21:48 ` Andrew Cooper
2022-03-18 23:10 ` Linus Torvalds
2022-03-18 23:42 ` Segher Boessenkool
2022-03-19 1:13 ` Linus Torvalds
2022-03-19 23:15 ` Andy Lutomirski
2022-03-18 22:09 ` Segher Boessenkool
2022-03-18 22:33 ` H. Peter Anvin
2022-03-18 22:36 ` David Laight [this message]
2022-03-18 22:47 ` H. Peter Anvin
2022-03-18 22:43 ` David Laight
2022-03-18 23:03 ` H. Peter Anvin
2022-03-18 23:04 ` Segher Boessenkool
2022-03-18 23:52 ` David Laight
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