Commit 42ea22e7 authored by zhoumin's avatar zhoumin Committed by Steven Rostedt (Google)
Browse files

ftrace: Add cond_resched() to ftrace_graph_set_hash() 

When the kernel contains a large number of functions that can be traced,
the loop in ftrace_graph_set_hash() may take a lot of time to execute.
This may trigger the softlockup watchdog.

Add cond_resched() within the loop to allow the kernel to remain
responsive even when processing a large number of functions.

This matches the cond_resched() that is used in other locations of the
code that iterates over all functions that can be traced.

Cc: stable@vger.kernel.org
Fixes: b9b0c831 ("ftrace: Convert graph filter to use hash tables")
Link: https://lore.kernel.org/tencent_3E06CE338692017B5809534B9C5C03DA7705@qq.com


Signed-off-by: default avatarzhoumin <teczm@foxmail.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 2c9ee74a

kernel/trace/ftrace.c

+1 −0
Original line number Diff line number Diff line
@@ -6855,6 +6855,7 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) 
				}

			}

		}

		cond_resched();

	} while_for_each_ftrace_rec();



	return fail ? -EINVAL : 0;