public inbox for glibc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "hjl.tools at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug libc/28537] New: x86: atomic_compare_and_exchange_[val|bool]_acq isn't optimized
Date: Wed, 03 Nov 2021 14:57:09 +0000 [thread overview]
Message-ID: <bug-28537-131@http.sourceware.org/bugzilla/> (raw)
https://sourceware.org/bugzilla/show_bug.cgi?id=28537
Bug ID: 28537
Summary: x86: atomic_compare_and_exchange_[val|bool]_acq isn't
optimized
Product: glibc
Version: 2.34
Status: NEW
Severity: normal
Priority: P2
Component: libc
Assignee: unassigned at sourceware dot org
Reporter: hjl.tools at gmail dot com
CC: drepper.fsp at gmail dot com
Target Milestone: ---
Target: i386,x86-64
>From the CPU's point of view, getting a cache line for writing is more
expensive than reading. See Appendix A.2 Spinlock in:
https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/xeon-lock-scaling-analysis-paper.pdf
The full compare and swap will grab the cache line exclusive and causes
excessive cache line bouncing.
--
You are receiving this mail because:
You are on the CC list for the bug.
next reply other threads:[~2021-11-03 14:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 14:57 hjl.tools at gmail dot com [this message]
2022-01-25 18:11 ` [Bug libc/28537] " hjl.tools at gmail dot com
2022-01-26 6:42 ` sam at gentoo dot org
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=bug-28537-131@http.sourceware.org/bugzilla/ \
--to=sourceware-bugzilla@sourceware.org \
--cc=glibc-bugs@sourceware.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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).