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authorPeter Zijlstra <peterz@infradead.org>2017-03-03 10:13:38 +0100
committerIngo Molnar <mingo@kernel.org>2017-08-10 12:29:03 +0200
commitd92a8cfcb37ecd1315269dab741f073b63b3a8b6 (patch)
treebd081c6309a48d23ae074e2035105be13622b005
parenta9668cd6ee288c4838bc668880ac085be551cac2 (diff)
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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>
-rw-r--r--drivers/gpu/drm/i915/i915_debugfs.c5
-rw-r--r--include/linux/lockdep.h11
-rw-r--r--include/linux/sched.h1
-rw-r--r--include/linux/sched/mm.h8
-rw-r--r--kernel/locking/lockdep.c95
-rw-r--r--kernel/locking/lockdep_states.h1
-rw-r--r--mm/page_alloc.c49
-rw-r--r--mm/slab.h6
-rw-r--r--mm/slob.c6
-rw-r--r--mm/vmscan.c13
10 files changed, 75 insertions, 120 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 00d8967c8512..0511fce5c947 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -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();
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index fffe49f188e6..0a4c02c2d7a2 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -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)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8337e2db0bb2..57db70ec70d0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -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
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 2b24a6974847..2b0a281f9d26 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -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;
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 7d2499bec5fe..986f2fa79dbb 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -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,
diff --git a/kernel/locking/lockdep_states.h b/kernel/locking/lockdep_states.h
index 995b0cc2b84c..35ca09f2ed0b 100644
--- a/kernel/locking/lockdep_states.h
+++ b/kernel/locking/lockdep_states.h
@@ -6,4 +6,3 @@
*/
LOCKDEP_STATE(HARDIRQ)
LOCKDEP_STATE(SOFTIRQ)
-LOCKDEP_STATE(RECLAIM_FS)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fc32aa81f359..c20d89601802 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -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);
diff --git a/mm/slab.h b/mm/slab.h
index 6885e1192ec5..073362816acc 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -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))
diff --git a/mm/slob.c b/mm/slob.c
index 1bae78d71096..a8bd6fa11a66 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -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);
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;
}