On Wed, Nov 13, 2019 at 10:40:58AM +0800, Alex Shi wrote: > > > ?? 2019/11/12 ????10:38, Matthew Wilcox ????: > > On Tue, Nov 12, 2019 at 10:06:26PM +0800, Alex Shi wrote: > >> Intel 0day report there are performance regression on this patchset. > >> The detailed info points to rcu_read_lock + PROVE_LOCKING which causes > >> queued_spin_lock_slowpath waiting too long time to get lock. > >> Remove rcu_read_lock is safe here since we had a spinlock hold. > > Argh. You have not sent these patches in a properly reviewable form! > > I wasted all that time reviewing the earlier patch in this series only to > > find out that you changed it here. FIX THE PATCH, don't send a fix-patch > > on top of it! > > > > Hi Matthew, > > Very sorry for your time! The main reasons I use a separate patch since a, Intel 0day asking me to credit their are founding, and I don't know how to give a clearly/elegant explanation for a non-exist regression in a fixed patch. b, this regression is kindly pretty tricky. Maybe it's better saying thanks in version change log of cover-letter? > Add something like this to the patch [lkp@xxxxxxxxx: Fix RCU-related regression reported by LKP robot] Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> ... -- Mel Gorman SUSE Labs
