]> git.ipfire.org Git - thirdparty/glibc.git/commit
projects / thirdparty / glibc.git / commit
? search:
summary | shortlog | log | commit | commitdiff | tree
(parent: f448208) | patch
nptl: Effectively skip CAS in spinlock loop
authorJangwoong Kim <6812skiii@gmail.com>
Tue, 14 Dec 2021 12:30:51 +0000 (21:30 +0900)
committerH.J. Lu <hjl.tools@gmail.com>
Thu, 20 Jan 2022 13:05:09 +0000 (05:05 -0800)
commit6b8dbbd03ac88f169b65b5c7d7278576a11d2e44
tree8c6053c6aabaea50c6706ecfb94eac3b8ca6ff83tree
parentf44820821a4ecdbb398375201b7c4ab9a1dd5983commit | diff
nptl: Effectively skip CAS in spinlock loop

The commit:
"Add LLL_MUTEX_READ_LOCK [BZ #28537]"
SHA1: d672a98a1af106bd68deb15576710cd61363f7a6

introduced LLL_MUTEX_READ_LOCK, to skip CAS in spinlock loop
if atomic load fails. But, "continue" inside of do-while loop
does not skip the evaluation of escape expression, thus CAS
is not skipped.

Replace do-while with while and skip LLL_MUTEX_TRYLOCK if
LLL_MUTEX_READ_LOCK fails.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
nptl/pthread_mutex_lock.c diff | blob | blame | history
A mirror of the official glibc repository