diff options
| author | Usama Arif <usama.arif@linux.dev> | 2026-09-16 07:15:30 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@kernel.org> | 2026-09-29 20:55:51 +0200 |
| commit | 75990fb534e858ac61ae7651c4695e0905a04443 (patch) | |
| tree | bd9cdea1c289316efd42fa5fd43b81a5fa982663 /scripts/basic/split-include.c | |
| parent | a59a940ff89fcaf305362443335f99010ff3b9cf (diff) | |
| download | linux-75990fb534e858ac61ae7651c4695e0905a04443.tar.gz linux-75990fb534e858ac61ae7651c4695e0905a04443.zip | |
tick/nohz: Remove redundant local_irq_save()/restore()
tick_nohz_update_jiffies() is only reached through tick_irq_enter() from
hard interrupt entry, where local interrupts are already disabled.
tick_do_update_jiffies64() requires interrupts to be disabled. The
local_irq_save()/local_irq_restore() pair around it therefore provides no
additional interrupt exclusion.
Remove it and assert the caller invariant instead.
On x86-64, this avoids the redundant RFLAGS save, CLI, saved-IF test and
conditional branch on the tick-stopped path.
On a 252-CPU host running a Thrift RPC service, tick_irq_enter() ran
165,116 times/s out of 212-244k interrupts/s. Only calls with
TS_FLAG_STOPPED reach the optimized path, so this is an upper bound on
its execution rate.
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://patch.msgid.link/20260916141530.3423310-1-usama.arif@linux.dev
Diffstat (limited to 'scripts/basic/split-include.c')
0 files changed, 0 insertions, 0 deletions