Messages in this thread Patch in this message |  | | Date | Wed, 14 Dec 2022 09:01:39 -0500 | From | Steven Rostedt <> | Subject | [for-next][PATCH 6/8] ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels |
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From: "gpiccoli@igalia.com" <gpiccoli@igalia.com>
The function match_records() may take a while due to a large number of string comparisons, so when in PREEMPT_VOLUNTARY kernels we could face RCU stalls due to that.
Add a cond_resched() to prevent that.
Link: https://lkml.kernel.org/r/20221115204847.593616-1-gpiccoli@igalia.com
Cc: Mark Rutland <mark.rutland@arm.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> # from RCU CPU stall warning perspective Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> --- kernel/trace/ftrace.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d04552c0c275..b8e374a372e5 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4204,6 +4204,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod) } found = 1; } + cond_resched(); } while_for_each_ftrace_rec(); out_unlock: mutex_unlock(&ftrace_lock); -- 2.35.1
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