once: don't use a work queue to reset sleepable static key

Pointless overhead to use a work queue to reset the static key for a
DO_ONCE_SLEEPABLE() invocation.

Note that the previous code path included a BUG_ON() if the static key
was already disabled. Dropped that as part of this change because:
1) Use of BUG_ON() is highly discouraged.
2) There is a WARN_ON() in the static_branch_disable() code path
   that would provide adequate breadcrumbs to debug any issue.

Link: https://lkml.kernel.org/r/aWU4tfTju1l3oZCu@agluck-desk3
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/once.c b/lib/once.c
index 2c306f0e891e87ce033fbea2e1d431c3ea6ce4f6..8557eb489f34773ef01d838bafae06bc56c4c0e9 100644 (file)
--- a/lib/once.c
+++ b/lib/once.c
@@ -93,6 +93,6 @@ void __do_once_sleepable_done(bool *done, struct static_key_true *once_key,
 {
        *done = true;
        mutex_unlock(&once_mutex);
-       once_disable_jump(once_key, mod);
+       static_branch_disable(once_key);
 }
 EXPORT_SYMBOL(__do_once_sleepable_done);