From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>,
Frederic Weisbecker <frederic@kernel.org>,
Benjamin Segall <bsegall@google.com>,
Eric Dumazet <edumazet@google.com>,
Andrey Vagin <avagin@openvz.org>,
Pavel Tikhomirov <ptikhomirov@virtuozzo.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: [patch 02/11] posix-timers: Add cond_resched() to posix_timer_add() search loop
Date: Mon, 24 Feb 2025 11:15:25 +0100 (CET) [thread overview]
Message-ID: <20250224101343.078382991@linutronix.de> (raw)
In-Reply-To: 20250224095736.145530367@linutronix.de
From: Eric Dumazet <edumazet@google.com>
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@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250214135911.2037402-2-edumazet@google.com
---
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;
next prev parent reply other threads:[~2025-02-24 10:15 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-24 10:15 [patch 00/11] posix-timers: Rework the global hash table and provide a sane mechanism for CRIU Thomas Gleixner
2025-02-24 10:15 ` [patch 01/11] posix-timers: Initialise timer before adding it to the hash table Thomas Gleixner
2025-02-24 10:15 ` Thomas Gleixner [this message]
2025-02-24 10:15 ` [patch 03/11] posix-timers: Cleanup includes Thomas Gleixner
2025-02-24 10:15 ` [patch 04/11] posix-timers: Remove pointless unlock_timer() wrapper Thomas Gleixner
2025-02-24 16:21 ` Peter Zijlstra
2025-02-24 18:43 ` Thomas Gleixner
2025-02-24 21:55 ` Peter Zijlstra
2025-02-24 10:15 ` [patch 05/11] posix-timers: Rework timer removal Thomas Gleixner
2025-02-24 10:15 ` [patch 06/11] posix-timers: Make signal_struct::next_posix_timer_id an atomic_t Thomas Gleixner
2025-02-24 13:20 ` Peter Zijlstra
2025-02-24 13:34 ` Eric Dumazet
2025-02-24 19:38 ` Thomas Gleixner
2025-02-24 10:15 ` [patch 07/11] posix-timers: Improve hash table performance Thomas Gleixner
2025-02-24 19:45 ` Thomas Gleixner
2025-02-24 10:15 ` [patch 08/11] posix-timers: Make per process list RCU safe Thomas Gleixner
2025-02-24 10:15 ` [patch 09/11] posix-timers: Dont iterate /proc/$PID/timers with sighand::siglock held Thomas Gleixner
2025-02-24 10:15 ` [patch 10/11] posix-timers: Provide a mechanism to allocate a given timer ID Thomas Gleixner
2025-02-24 10:15 ` [patch 11/11] selftests/timers/posix-timers: Add a test for exact allocation mode Thomas Gleixner
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