diff options
author | Waiman Long <longman@redhat.com> | 2019-05-21 16:48:43 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-31 07:28:25 +0200 |
commit | 16a0c22def0219099d22d4b8bcf31367b0cc7ca6 (patch) | |
tree | b6cbb9ee646262c75818dbdfe05749284b5b023e /include/linux/rcupdate.h | |
parent | 07df68f0b878c61ca6ceeeee78c67ea64ae142fa (diff) |
rcu: Force inlining of rcu_read_lock()
[ Upstream commit 6da9f775175e516fc7229ceaa9b54f8f56aa7924 ]
When debugging options are turned on, the rcu_read_lock() function
might not be inlined. This results in lockdep's print_lock() function
printing "rcu_read_lock+0x0/0x70" instead of rcu_read_lock()'s caller.
For example:
[ 10.579995] =============================
[ 10.584033] WARNING: suspicious RCU usage
[ 10.588074] 4.18.0.memcg_v2+ #1 Not tainted
[ 10.593162] -----------------------------
[ 10.597203] include/linux/rcupdate.h:281 Illegal context switch in
RCU read-side critical section!
[ 10.606220]
[ 10.606220] other info that might help us debug this:
[ 10.606220]
[ 10.614280]
[ 10.614280] rcu_scheduler_active = 2, debug_locks = 1
[ 10.620853] 3 locks held by systemd/1:
[ 10.624632] #0: (____ptrval____) (&type->i_mutex_dir_key#5){.+.+}, at: lookup_slow+0x42/0x70
[ 10.633232] #1: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70
[ 10.640954] #2: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70
These "rcu_read_lock+0x0/0x70" strings are not providing any useful
information. This commit therefore forces inlining of the rcu_read_lock()
function so that rcu_read_lock()'s caller is instead shown.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux/rcupdate.h')
-rw-r--r-- | include/linux/rcupdate.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index f960c85cd9ec..8d570190e9b4 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -622,7 +622,7 @@ static inline void rcu_preempt_sleep_check(void) { } * read-side critical sections may be preempted and they may also block, but * only when acquiring spinlocks that are subject to priority inheritance. */ -static inline void rcu_read_lock(void) +static __always_inline void rcu_read_lock(void) { __rcu_read_lock(); __acquire(RCU); |