From: Josh Poimboeuf <jpoimboe@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH RFC 3/5] noinstr: Use asm_inline() in instrumentation_{begin,end}()
Date: Tue, 8 Apr 2025 01:21:16 -0700 [thread overview]
Message-ID: <7cb41fe7e87a003fc925164d5cc18efd8e95fcc0.1744098446.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1744098446.git.jpoimboe@kernel.org>
Use asm_inline() to prevent the compiler from making poor inlining
decisions based on the length of the objtool annotations.
For a defconfig kernel built with GCC 14.2.1, bloat-o-meter reports a
0.18% text size increase:
add/remove: 88/433 grow/shrink: 967/487 up/down: 87579/-52630 (34949)
Total: Before=19448407, After=19483356, chg +0.18%
Presumably the text growth is due to increased inlining. A net total of
345 functions were removed.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/instrumentation.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h
index bf675a8aef8a..b1007407d272 100644
--- a/include/linux/instrumentation.h
+++ b/include/linux/instrumentation.h
@@ -9,7 +9,7 @@
/* Begin/end of an instrumentation safe region */
#define __instrumentation_begin(c) ({ \
- asm volatile(__stringify(c) ": nop\n\t" \
+ asm_inline volatile(__stringify(c) ": nop\n\t" \
ANNOTATE_INSTR_BEGIN(__ASM_BREF(c)) \
: : "i" (c)); \
})
@@ -47,7 +47,7 @@
* part of the condition block and does not escape.
*/
#define __instrumentation_end(c) ({ \
- asm volatile(__stringify(c) ": nop\n\t" \
+ asm_inline volatile(__stringify(c) ": nop\n\t" \
ANNOTATE_INSTR_END(__ASM_BREF(c)) \
: : "i" (c)); \
})
--
2.49.0
next prev parent reply other threads:[~2025-04-08 8:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-08 8:21 [PATCH RFC 0/5] x86/asm: Improve code generation Josh Poimboeuf
2025-04-08 8:21 ` [PATCH RFC 1/5] objtool: Remove ANNOTATE_IGNORE_ALTERNATIVE from CLAC/STAC Josh Poimboeuf
2025-04-08 18:07 ` Linus Torvalds
2025-04-08 20:45 ` [tip: objtool/urgent] " tip-bot2 for Josh Poimboeuf
2025-04-08 8:21 ` [PATCH RFC 2/5] objtool, x86/hweight: Remove ANNOTATE_IGNORE_ALTERNATIVE Josh Poimboeuf
2025-04-08 8:21 ` Josh Poimboeuf [this message]
2025-04-08 8:30 ` [PATCH RFC 3/5] noinstr: Use asm_inline() in instrumentation_{begin,end}() Ingo Molnar
2025-04-08 11:10 ` Uros Bizjak
2025-04-08 16:46 ` Josh Poimboeuf
2025-04-08 8:21 ` [PATCH RFC 4/5] x86/alternative: Improve code generation readability Josh Poimboeuf
2025-04-09 14:38 ` Peter Zijlstra
2025-04-09 17:41 ` Josh Poimboeuf
2025-04-09 18:02 ` Linus Torvalds
2025-04-09 19:51 ` Josh Poimboeuf
2025-04-09 21:20 ` Linus Torvalds
2025-04-09 21:27 ` Josh Poimboeuf
2025-04-09 21:55 ` Josh Poimboeuf
2025-04-16 23:30 ` Josh Poimboeuf
2025-04-08 8:21 ` [PATCH RFC 5/5] objtool: " Josh Poimboeuf
2025-04-09 14:40 ` Peter Zijlstra
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=7cb41fe7e87a003fc925164d5cc18efd8e95fcc0.1744098446.git.jpoimboe@kernel.org \
--to=jpoimboe@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=torvalds@linux-foundation.org \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®