Revert "block: reduce kblockd_mod_delayed_work_on() CPU consumption"

This reverts commit cb2ac2912a9ca7d3d26291c511939a41361d2d83.

Alex and the kernel test robot report that this causes a significant
performance regression with BFQ. I can reproduce that result, so let's
revert this one as we're close to -rc6 and we there's no point in trying
to rush a fix.

Link: https://lore.kernel.org/linux-block/1639853092.524jxfaem2.none@localhost/
Link: https://lore.kernel.org/lkml/20211219141852.GH14057@xsang-OptiPlex-9020/
Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index c1833f9..1378d08 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1484,8 +1484,6 @@ EXPORT_SYMBOL(kblockd_schedule_work);
 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork,
                                unsigned long delay)
 {
-       if (!delay)
-               return queue_work_on(cpu, kblockd_workqueue, &dwork->work);
        return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay);
 }
 EXPORT_SYMBOL(kblockd_mod_delayed_work_on);