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locking/lockdep: Rework FS_RECLAIM annotation

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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>
This commit is contained in:
Peter Zijlstra 2017-03-03 10:13:38 +01:00 committed by Ingo Molnar
parent a9668cd6ee
commit d92a8cfcb3
10 changed files with 75 additions and 120 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/gpu/drm/i915/i915_debugfs.c
View File

@ -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();

11
include/linux/lockdep.h
View File

@ -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)

1
include/linux/sched.h
View File

@ -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

8
include/linux/sched/mm.h
View File

@ -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;

95
kernel/locking/lockdep.c
View File

@ -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,

1
kernel/locking/lockdep_states.h
View File

@ -6,4 +6,3 @@
*/
LOCKDEP_STATE(HARDIRQ)
LOCKDEP_STATE(SOFTIRQ)
LOCKDEP_STATE(RECLAIM_FS)

49
mm/page_alloc.c
View File

@ -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);

6
mm/slab.h
View File

@ -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))

6
mm/slob.c
View File

@ -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
View File

@ -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;
}