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authorGuilherme G. Piccoli <[email protected]>2022-11-15 17:48:47 -0300
committerSteven Rostedt (Google) <[email protected]>2022-12-14 11:16:35 -0500
commitd0b24b4e91fcb8408c4979888547f86be514e337 (patch)
tree94fde9dab3e89b07ae4a9271f2ef74d59a7f7039
parentfb9f5ee9bf5cf7ebc8731a7033e57d98832dc650 (diff)
ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels
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/[email protected] Cc: Mark Rutland <[email protected]> Suggested-by: Steven Rostedt <[email protected]> Acked-by: Paul E. McKenney <[email protected]> # from RCU CPU stall warning perspective Signed-off-by: Guilherme G. Piccoli <[email protected]> Acked-by: Masami Hiramatsu (Google) <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]>
-rw-r--r--kernel/trace/ftrace.c1
1 files changed, 1 insertions, 0 deletions
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);