From 508ee037a30f1d4f6a1f8de2bd0d9866d4684625 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 9 Jul 2021 10:59:22 +0200 Subject: nptl: Use out-of-line wake function in __libc_lock_unlock slow path This slightly reduces code size, as can be seen below. __libc_lock_unlock is usually used along with __libc_lock_lock in the same function. __libc_lock_lock already has an out-of-line slow path, so this change should not introduce many additional non-leaf functions. This change also fixes a link failure in 32-bit Arm thumb mode because commit 1f9c804fbd699104adefbce9e56d2c8aa711b6b9 ("nptl: Use internal low-level lock type for !IS_IN (libc)") introduced __libc_do_syscall calls outside of libc. Before x86-64: text data bss dec hex filename 1937748 20456 54896 2013100 1eb7ac libc.so.6 25601 856 12768 39225 9939 nss/libnss_db.so.2 40310 952 25144 66406 10366 nss/libnss_files.so.2 After x86-64: text data bss dec hex filename 1935312 20456 54896 2010664 1eae28 libc.so.6 25559 864 12768 39191 9917 nss/libnss_db.so.2 39764 960 25144 65868 1014c nss/libnss_files.so.2 Before i686: 2110961 11272 39144 2161377 20fae1 libc.so.6 27243 428 12652 40323 9d83 nss/libnss_db.so.2 43062 476 25028 68566 10bd6 nss/libnss_files.so.2 After i686: 2107347 11272 39144 2157763 20ecc3 libc.so.6 26929 432 12652 40013 9c4d nss/libnss_db.so.2 43132 480 25028 68640 10c20 nss/libnss_files.so.2 Reviewed-by: Adhemerval Zanella --- nptl/Versions | 1 + nptl/lowlevellock.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+) (limited to 'nptl') diff --git a/nptl/Versions b/nptl/Versions index 2a75f01..3221de8 100644 --- a/nptl/Versions +++ b/nptl/Versions @@ -380,6 +380,7 @@ libc { } GLIBC_PRIVATE { __libc_alloca_cutoff; + __lll_lock_wake_private; __lll_lock_wait_private; __nptl_create_event; __nptl_death_event; diff --git a/nptl/lowlevellock.c b/nptl/lowlevellock.c index 2d077d8..4f88178 100644 --- a/nptl/lowlevellock.c +++ b/nptl/lowlevellock.c @@ -52,6 +52,20 @@ __lll_lock_wait (int *futex, int private) } libc_hidden_def (__lll_lock_wait) +void +__lll_lock_wake_private (int *futex) +{ + lll_futex_wake (futex, 1, LLL_PRIVATE); +} +libc_hidden_def (__lll_lock_wake_private) + +void +__lll_lock_wake (int *futex, int private) +{ + lll_futex_wake (futex, 1, private); +} +libc_hidden_def (__lll_lock_wake) + #if ENABLE_ELISION_SUPPORT int __pthread_force_elision __attribute__ ((nocommon)); libc_hidden_data_def (__pthread_force_elision) -- cgit v1.1