From f39cdaebb89dc3e6dd4f3e75b6d4e87ef12190af Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 20 Jun 2012 12:53:03 -0700 Subject: [PATCH] fault-inject: avoid call to random32() if fault injection is disabled After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub fault injection wasn't enabled at runtime. should_fail forces a comparison against random32() even if probability is 0: if (attr->probability <= random32() % 100) return false; Add a check up front for probability == 0 and avoid all of the more complicated checks. Signed-off-by: Anton Blanchard Acked-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/fault-inject.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/fault-inject.c b/lib/fault-inject.c index 6805453c18e7..f7210ad6cffd 100644 --- a/lib/fault-inject.c +++ b/lib/fault-inject.c @@ -101,6 +101,10 @@ static inline bool fail_stacktrace(struct fault_attr *attr) bool should_fail(struct fault_attr *attr, ssize_t size) { + /* No need to check any other properties if the probability is 0 */ + if (attr->probability == 0) + return false; + if (attr->task_filter && !fail_task(attr, current)) return false; -- 2.20.1