From d92a8cfcb37ecd1315269dab741f073b63b3a8b6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 3 Mar 2017 10:13:38 +0100 Subject: locking/lockdep: Rework FS_RECLAIM annotation A while ago someone, and I cannot find the email just now, asked if we could not implement the RECLAIM_FS inversion stuff with a 'fake' lock like we use for other things like workqueues etc. I think this should be possible which allows reducing the 'irq' states and will reduce the amount of __bfs() lookups we do. Removing the 1 IRQ state results in 4 less __bfs() walks per dependency, improving lockdep performance. And by moving this annotation out of the lockdep code it becomes easier for the mm people to extend. Signed-off-by: Peter Zijlstra (Intel) Cc: Byungchul Park Cc: Linus Torvalds Cc: Mel Gorman Cc: Michal Hocko Cc: Nikolay Borisov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: iamjoonsoo.kim@lge.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Signed-off-by: Ingo Molnar --- mm/vmscan.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index a1af041930a6..f957afe900ec 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3525,8 +3525,6 @@ static int kswapd(void *p) }; const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); - lockdep_set_current_reclaim_state(GFP_KERNEL); - if (!cpumask_empty(cpumask)) set_cpus_allowed_ptr(tsk, cpumask); current->reclaim_state = &reclaim_state; @@ -3585,14 +3583,15 @@ kswapd_try_sleep: */ trace_mm_vmscan_kswapd_wake(pgdat->node_id, classzone_idx, alloc_order); + fs_reclaim_acquire(GFP_KERNEL); reclaim_order = balance_pgdat(pgdat, alloc_order, classzone_idx); + fs_reclaim_release(GFP_KERNEL); if (reclaim_order < alloc_order) goto kswapd_try_sleep; } tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD); current->reclaim_state = NULL; - lockdep_clear_current_reclaim_state(); return 0; } @@ -3655,14 +3654,14 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim) unsigned int noreclaim_flag; noreclaim_flag = memalloc_noreclaim_save(); - lockdep_set_current_reclaim_state(sc.gfp_mask); + fs_reclaim_acquire(sc.gfp_mask); reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; nr_reclaimed = do_try_to_free_pages(zonelist, &sc); p->reclaim_state = NULL; - lockdep_clear_current_reclaim_state(); + fs_reclaim_release(sc.gfp_mask); memalloc_noreclaim_restore(noreclaim_flag); return nr_reclaimed; @@ -3847,7 +3846,7 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in */ noreclaim_flag = memalloc_noreclaim_save(); p->flags |= PF_SWAPWRITE; - lockdep_set_current_reclaim_state(sc.gfp_mask); + fs_reclaim_acquire(sc.gfp_mask); reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; @@ -3862,9 +3861,9 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in } p->reclaim_state = NULL; + fs_reclaim_release(gfp_mask); current->flags &= ~PF_SWAPWRITE; memalloc_noreclaim_restore(noreclaim_flag); - lockdep_clear_current_reclaim_state(); return sc.nr_reclaimed >= nr_pages; } -- cgit