[PATCH v3 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal()
From: Liao Chang <hidden>
Date: 2024-08-15 01:55:50
Also in:
bpf, linux-perf-users, lkml
Subsystem:
performance events subsystem, the rest, uprobes · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Masami Hiramatsu, Oleg Nesterov
Since clearing a bit in thread_info is an atomic operation, the spinlock is redundant and can be removed, reducing lock contention is good for performance. Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Liao Chang <redacted> --- kernel/events/uprobes.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 73cc47708679..76a51a1f51e2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c@@ -1979,9 +1979,7 @@ bool uprobe_deny_signal(void) WARN_ON_ONCE(utask->state != UTASK_SSTEP); if (task_sigpending(t)) { - spin_lock_irq(&t->sighand->siglock); clear_tsk_thread_flag(t, TIF_SIGPENDING); - spin_unlock_irq(&t->sighand->siglock); if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) { utask->state = UTASK_SSTEP_TRAPPED;
--
2.34.1