forked from mirrors/linux
		
	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) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> 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 <mingo@kernel.org>
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					 10 changed files with 75 additions and 120 deletions
				
			
		|  | @ -28,6 +28,7 @@ | |||
| 
 | ||||
| #include <linux/debugfs.h> | ||||
| #include <linux/sort.h> | ||||
| #include <linux/sched/mm.h> | ||||
| #include "intel_drv.h" | ||||
| 
 | ||||
| static inline struct drm_i915_private *node_to_i915(struct drm_info_node *node) | ||||
|  | @ -4331,7 +4332,7 @@ i915_drop_caches_set(void *data, u64 val) | |||
| 		mutex_unlock(&dev->struct_mutex); | ||||
| 	} | ||||
| 
 | ||||
| 	lockdep_set_current_reclaim_state(GFP_KERNEL); | ||||
| 	fs_reclaim_acquire(GFP_KERNEL); | ||||
| 	if (val & DROP_BOUND) | ||||
| 		i915_gem_shrink(dev_priv, LONG_MAX, I915_SHRINK_BOUND); | ||||
| 
 | ||||
|  | @ -4340,7 +4341,7 @@ i915_drop_caches_set(void *data, u64 val) | |||
| 
 | ||||
| 	if (val & DROP_SHRINK_ALL) | ||||
| 		i915_gem_shrink_all(dev_priv); | ||||
| 	lockdep_clear_current_reclaim_state(); | ||||
| 	fs_reclaim_release(GFP_KERNEL); | ||||
| 
 | ||||
| 	if (val & DROP_FREED) { | ||||
| 		synchronize_rcu(); | ||||
|  |  | |||
|  | @ -29,7 +29,7 @@ extern int lock_stat; | |||
|  * We'd rather not expose kernel/lockdep_states.h this wide, but we do need | ||||
|  * the total number of states... :-( | ||||
|  */ | ||||
| #define XXX_LOCK_USAGE_STATES		(1+3*4) | ||||
| #define XXX_LOCK_USAGE_STATES		(1+2*4) | ||||
| 
 | ||||
| /*
 | ||||
|  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes | ||||
|  | @ -363,10 +363,6 @@ static inline void lock_set_subclass(struct lockdep_map *lock, | |||
| 
 | ||||
| extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip); | ||||
| 
 | ||||
| extern void lockdep_set_current_reclaim_state(gfp_t gfp_mask); | ||||
| extern void lockdep_clear_current_reclaim_state(void); | ||||
| extern void lockdep_trace_alloc(gfp_t mask); | ||||
| 
 | ||||
| struct pin_cookie { unsigned int val; }; | ||||
| 
 | ||||
| #define NIL_COOKIE (struct pin_cookie){ .val = 0U, } | ||||
|  | @ -375,7 +371,7 @@ extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock); | |||
| extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie); | ||||
| extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); | ||||
| 
 | ||||
| # define INIT_LOCKDEP				.lockdep_recursion = 0, .lockdep_reclaim_gfp = 0, | ||||
| # define INIT_LOCKDEP				.lockdep_recursion = 0, | ||||
| 
 | ||||
| #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0) | ||||
| 
 | ||||
|  | @ -416,9 +412,6 @@ static inline void lockdep_on(void) | |||
| # define lock_downgrade(l, i)			do { } while (0) | ||||
| # define lock_set_class(l, n, k, s, i)		do { } while (0) | ||||
| # define lock_set_subclass(l, s, i)		do { } while (0) | ||||
| # define lockdep_set_current_reclaim_state(g)	do { } while (0) | ||||
| # define lockdep_clear_current_reclaim_state()	do { } while (0) | ||||
| # define lockdep_trace_alloc(g)			do { } while (0) | ||||
| # define lockdep_info()				do { } while (0) | ||||
| # define lockdep_init_map(lock, name, key, sub) \ | ||||
| 		do { (void)(name); (void)(key); } while (0) | ||||
|  |  | |||
|  | @ -846,7 +846,6 @@ struct task_struct { | |||
| 	int				lockdep_depth; | ||||
| 	unsigned int			lockdep_recursion; | ||||
| 	struct held_lock		held_locks[MAX_LOCK_DEPTH]; | ||||
| 	gfp_t				lockdep_reclaim_gfp; | ||||
| #endif | ||||
| 
 | ||||
| #ifdef CONFIG_UBSAN | ||||
|  |  | |||
|  | @ -167,6 +167,14 @@ static inline gfp_t current_gfp_context(gfp_t flags) | |||
| 	return flags; | ||||
| } | ||||
| 
 | ||||
| #ifdef CONFIG_LOCKDEP | ||||
| extern void fs_reclaim_acquire(gfp_t gfp_mask); | ||||
| extern void fs_reclaim_release(gfp_t gfp_mask); | ||||
| #else | ||||
| static inline void fs_reclaim_acquire(gfp_t gfp_mask) { } | ||||
| static inline void fs_reclaim_release(gfp_t gfp_mask) { } | ||||
| #endif | ||||
| 
 | ||||
| static inline unsigned int memalloc_noio_save(void) | ||||
| { | ||||
| 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO; | ||||
|  |  | |||
|  | @ -344,14 +344,12 @@ EXPORT_SYMBOL(lockdep_on); | |||
| #if VERBOSE | ||||
| # define HARDIRQ_VERBOSE	1 | ||||
| # define SOFTIRQ_VERBOSE	1 | ||||
| # define RECLAIM_VERBOSE	1 | ||||
| #else | ||||
| # define HARDIRQ_VERBOSE	0 | ||||
| # define SOFTIRQ_VERBOSE	0 | ||||
| # define RECLAIM_VERBOSE	0 | ||||
| #endif | ||||
| 
 | ||||
| #if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE || RECLAIM_VERBOSE | ||||
| #if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE | ||||
| /*
 | ||||
|  * Quick filtering for interesting events: | ||||
|  */ | ||||
|  | @ -2567,14 +2565,6 @@ static int SOFTIRQ_verbose(struct lock_class *class) | |||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int RECLAIM_FS_verbose(struct lock_class *class) | ||||
| { | ||||
| #if RECLAIM_VERBOSE | ||||
| 	return class_filter(class); | ||||
| #endif | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| #define STRICT_READ_CHECKS	1 | ||||
| 
 | ||||
| static int (*state_verbose_f[])(struct lock_class *class) = { | ||||
|  | @ -2870,57 +2860,6 @@ void trace_softirqs_off(unsigned long ip) | |||
| 		debug_atomic_inc(redundant_softirqs_off); | ||||
| } | ||||
| 
 | ||||
| static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags) | ||||
| { | ||||
| 	struct task_struct *curr = current; | ||||
| 
 | ||||
| 	if (unlikely(!debug_locks)) | ||||
| 		return; | ||||
| 
 | ||||
| 	gfp_mask = current_gfp_context(gfp_mask); | ||||
| 
 | ||||
| 	/* no reclaim without waiting on it */ | ||||
| 	if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) | ||||
| 		return; | ||||
| 
 | ||||
| 	/* this guy won't enter reclaim */ | ||||
| 	if ((curr->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC)) | ||||
| 		return; | ||||
| 
 | ||||
| 	/* We're only interested __GFP_FS allocations for now */ | ||||
| 	if (!(gfp_mask & __GFP_FS) || (curr->flags & PF_MEMALLOC_NOFS)) | ||||
| 		return; | ||||
| 
 | ||||
| 	/*
 | ||||
| 	 * Oi! Can't be having __GFP_FS allocations with IRQs disabled. | ||||
| 	 */ | ||||
| 	if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))) | ||||
| 		return; | ||||
| 
 | ||||
| 	/* Disable lockdep if explicitly requested */ | ||||
| 	if (gfp_mask & __GFP_NOLOCKDEP) | ||||
| 		return; | ||||
| 
 | ||||
| 	mark_held_locks(curr, RECLAIM_FS); | ||||
| } | ||||
| 
 | ||||
| static void check_flags(unsigned long flags); | ||||
| 
 | ||||
| void lockdep_trace_alloc(gfp_t gfp_mask) | ||||
| { | ||||
| 	unsigned long flags; | ||||
| 
 | ||||
| 	if (unlikely(current->lockdep_recursion)) | ||||
| 		return; | ||||
| 
 | ||||
| 	raw_local_irq_save(flags); | ||||
| 	check_flags(flags); | ||||
| 	current->lockdep_recursion = 1; | ||||
| 	__lockdep_trace_alloc(gfp_mask, flags); | ||||
| 	current->lockdep_recursion = 0; | ||||
| 	raw_local_irq_restore(flags); | ||||
| } | ||||
| 
 | ||||
| static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) | ||||
| { | ||||
| 	/*
 | ||||
|  | @ -2966,22 +2905,6 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) | |||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	/*
 | ||||
| 	 * We reuse the irq context infrastructure more broadly as a general | ||||
| 	 * context checking code. This tests GFP_FS recursion (a lock taken | ||||
| 	 * during reclaim for a GFP_FS allocation is held over a GFP_FS | ||||
| 	 * allocation). | ||||
| 	 */ | ||||
| 	if (!hlock->trylock && (curr->lockdep_reclaim_gfp & __GFP_FS)) { | ||||
| 		if (hlock->read) { | ||||
| 			if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS_READ)) | ||||
| 					return 0; | ||||
| 		} else { | ||||
| 			if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS)) | ||||
| 					return 0; | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	return 1; | ||||
| } | ||||
| 
 | ||||
|  | @ -3040,10 +2963,6 @@ static inline int separate_irq_context(struct task_struct *curr, | |||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| void lockdep_trace_alloc(gfp_t gfp_mask) | ||||
| { | ||||
| } | ||||
| 
 | ||||
| #endif /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */ | ||||
| 
 | ||||
| /*
 | ||||
|  | @ -3952,18 +3871,6 @@ void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie) | |||
| } | ||||
| EXPORT_SYMBOL_GPL(lock_unpin_lock); | ||||
| 
 | ||||
| void lockdep_set_current_reclaim_state(gfp_t gfp_mask) | ||||
| { | ||||
| 	current->lockdep_reclaim_gfp = current_gfp_context(gfp_mask); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(lockdep_set_current_reclaim_state); | ||||
| 
 | ||||
| void lockdep_clear_current_reclaim_state(void) | ||||
| { | ||||
| 	current->lockdep_reclaim_gfp = 0; | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(lockdep_clear_current_reclaim_state); | ||||
| 
 | ||||
| #ifdef CONFIG_LOCK_STAT | ||||
| static int | ||||
| print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock, | ||||
|  |  | |||
|  | @ -6,4 +6,3 @@ | |||
|  */ | ||||
| LOCKDEP_STATE(HARDIRQ) | ||||
| LOCKDEP_STATE(SOFTIRQ) | ||||
| LOCKDEP_STATE(RECLAIM_FS) | ||||
|  |  | |||
|  | @ -66,6 +66,7 @@ | |||
| #include <linux/kthread.h> | ||||
| #include <linux/memcontrol.h> | ||||
| #include <linux/ftrace.h> | ||||
| #include <linux/lockdep.h> | ||||
| 
 | ||||
| #include <asm/sections.h> | ||||
| #include <asm/tlbflush.h> | ||||
|  | @ -3490,6 +3491,47 @@ should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_fla | |||
| } | ||||
| #endif /* CONFIG_COMPACTION */ | ||||
| 
 | ||||
| #ifdef CONFIG_LOCKDEP | ||||
| struct lockdep_map __fs_reclaim_map = | ||||
| 	STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map); | ||||
| 
 | ||||
| static bool __need_fs_reclaim(gfp_t gfp_mask) | ||||
| { | ||||
| 	gfp_mask = current_gfp_context(gfp_mask); | ||||
| 
 | ||||
| 	/* no reclaim without waiting on it */ | ||||
| 	if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) | ||||
| 		return false; | ||||
| 
 | ||||
| 	/* this guy won't enter reclaim */ | ||||
| 	if ((current->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC)) | ||||
| 		return false; | ||||
| 
 | ||||
| 	/* We're only interested __GFP_FS allocations for now */ | ||||
| 	if (!(gfp_mask & __GFP_FS)) | ||||
| 		return false; | ||||
| 
 | ||||
| 	if (gfp_mask & __GFP_NOLOCKDEP) | ||||
| 		return false; | ||||
| 
 | ||||
| 	return true; | ||||
| } | ||||
| 
 | ||||
| void fs_reclaim_acquire(gfp_t gfp_mask) | ||||
| { | ||||
| 	if (__need_fs_reclaim(gfp_mask)) | ||||
| 		lock_map_acquire(&__fs_reclaim_map); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(fs_reclaim_acquire); | ||||
| 
 | ||||
| void fs_reclaim_release(gfp_t gfp_mask) | ||||
| { | ||||
| 	if (__need_fs_reclaim(gfp_mask)) | ||||
| 		lock_map_release(&__fs_reclaim_map); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(fs_reclaim_release); | ||||
| #endif | ||||
| 
 | ||||
| /* Perform direct synchronous page reclaim */ | ||||
| static int | ||||
| __perform_reclaim(gfp_t gfp_mask, unsigned int order, | ||||
|  | @ -3504,7 +3546,7 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order, | |||
| 	/* We now go into synchronous reclaim */ | ||||
| 	cpuset_memory_pressure_bump(); | ||||
| 	noreclaim_flag = memalloc_noreclaim_save(); | ||||
| 	lockdep_set_current_reclaim_state(gfp_mask); | ||||
| 	fs_reclaim_acquire(gfp_mask); | ||||
| 	reclaim_state.reclaimed_slab = 0; | ||||
| 	current->reclaim_state = &reclaim_state; | ||||
| 
 | ||||
|  | @ -3512,7 +3554,7 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order, | |||
| 								ac->nodemask); | ||||
| 
 | ||||
| 	current->reclaim_state = NULL; | ||||
| 	lockdep_clear_current_reclaim_state(); | ||||
| 	fs_reclaim_release(gfp_mask); | ||||
| 	memalloc_noreclaim_restore(noreclaim_flag); | ||||
| 
 | ||||
| 	cond_resched(); | ||||
|  | @ -4041,7 +4083,8 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, | |||
| 			*alloc_flags |= ALLOC_CPUSET; | ||||
| 	} | ||||
| 
 | ||||
| 	lockdep_trace_alloc(gfp_mask); | ||||
| 	fs_reclaim_acquire(gfp_mask); | ||||
| 	fs_reclaim_release(gfp_mask); | ||||
| 
 | ||||
| 	might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM); | ||||
| 
 | ||||
|  |  | |||
|  | @ -43,6 +43,7 @@ struct kmem_cache { | |||
| #include <linux/kasan.h> | ||||
| #include <linux/kmemleak.h> | ||||
| #include <linux/random.h> | ||||
| #include <linux/sched/mm.h> | ||||
| 
 | ||||
| /*
 | ||||
|  * State of the slab allocator. | ||||
|  | @ -412,7 +413,10 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, | |||
| 						     gfp_t flags) | ||||
| { | ||||
| 	flags &= gfp_allowed_mask; | ||||
| 	lockdep_trace_alloc(flags); | ||||
| 
 | ||||
| 	fs_reclaim_acquire(flags); | ||||
| 	fs_reclaim_release(flags); | ||||
| 
 | ||||
| 	might_sleep_if(gfpflags_allow_blocking(flags)); | ||||
| 
 | ||||
| 	if (should_failslab(s, flags)) | ||||
|  |  | |||
|  | @ -432,7 +432,8 @@ __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller) | |||
| 
 | ||||
| 	gfp &= gfp_allowed_mask; | ||||
| 
 | ||||
| 	lockdep_trace_alloc(gfp); | ||||
| 	fs_reclaim_acquire(gfp); | ||||
| 	fs_reclaim_release(gfp); | ||||
| 
 | ||||
| 	if (size < PAGE_SIZE - align) { | ||||
| 		if (!size) | ||||
|  | @ -538,7 +539,8 @@ static void *slob_alloc_node(struct kmem_cache *c, gfp_t flags, int node) | |||
| 
 | ||||
| 	flags &= gfp_allowed_mask; | ||||
| 
 | ||||
| 	lockdep_trace_alloc(flags); | ||||
| 	fs_reclaim_acquire(flags); | ||||
| 	fs_reclaim_release(flags); | ||||
| 
 | ||||
| 	if (c->size < PAGE_SIZE) { | ||||
| 		b = slob_alloc(c->size, flags, c->align, node); | ||||
|  |  | |||
							
								
								
									
										13
									
								
								mm/vmscan.c
									
									
									
									
									
								
							
							
						
						
									
										13
									
								
								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 @@ static int kswapd(void *p) | |||
| 		 */ | ||||
| 		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; | ||||
| } | ||||
| 
 | ||||
|  |  | |||
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	 Peter Zijlstra
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