dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

futex: Remove support for IMMUTABLE

Browse Source 
The FH_FLAG_IMMUTABLE flag was meant to avoid the reference counting on
the private hash and so to avoid the performance regression on big
machines.
With the switch to per-CPU counter this is no longer needed. That flag
was never useable on any released kernel.

Remove any support for IMMUTABLE while preserve the flags argument and
enforce it to be zero.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250710110011.384614-5-bigeasy@linutronix.de
This commit is contained in:
Sebastian Andrzej Siewior
2025-07-11 16:02:01 +02:00
committed by Peter Zijlstra
parent fb3c553da7
commit 760e6f7bef
2 changed files with 3 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/uapi/linux/prctl.h
-2
View File
@@ -367,8 +367,6 @@ struct prctl_mm_map {
/* FUTEX hash management */
#define PR_FUTEX_HASH 78
# define PR_FUTEX_HASH_SET_SLOTS 1
# define FH_FLAG_IMMUTABLE (1ULL << 0)
# define PR_FUTEX_HASH_GET_SLOTS 2
# define PR_FUTEX_HASH_GET_IMMUTABLE 3
#endif /* _LINUX_PRCTL_H */