[patch V3 03/18] posix-timers: Add cond_resched() to posix_timer_add() search loop

From: Thomas Gleixner
Date: Sat Mar 08 2025 - 11:49:09 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

With a large number of POSIX timers the search for a valid ID might cause a
soft lockup on PREEMPT_NONE/VOLUNTARY kernels.

Add cond_resched() to the loop to prevent that.

[ tglx: Split out from Eric's series ]

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20250214135911.2037402-2-edumazet@xxxxxxxxxx

---
kernel/time/posix-timers.c | 1 +
1 file changed, 1 insertion(+)

--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -144,6 +144,7 @@ static int posix_timer_add(struct k_itim
return id;
}
spin_unlock(&hash_lock);
+ cond_resched();
}
/* POSIX return code when no timer ID could be allocated */
return -EAGAIN;