From d64810f56147b53e92228c31442e925576314aa2 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 11 Feb 2015 15:01:13 +1030 Subject: [PATCH] module: Annotate nested sleep in resolve_symbol() Because wait_event() loops are safe vs spurious wakeups we can allow the occasional sleep -- which ends up being very similar. Reported-by: Dave Jones Signed-off-by: Peter Zijlstra (Intel) Tested-by: Dave Jones Signed-off-by: Rusty Russell --- kernel/module.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/module.c b/kernel/module.c index 2461370813b3..d7a92682fba3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1225,6 +1225,12 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, const unsigned long *crc; int err; + /* + * The module_mutex should not be a heavily contended lock; + * if we get the occasional sleep here, we'll go an extra iteration + * in the wait_event_interruptible(), which is harmless. + */ + sched_annotate_sleep(); mutex_lock(&module_mutex); sym = find_symbol(name, &owner, &crc, !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);