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authorPeter Zijlstra <peterz@infradead.org>2017-03-03 12:13:38 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:29:03 +0300
commitd92a8cfcb37ecd1315269dab741f073b63b3a8b6 (patch)
treebd081c6309a48d23ae074e2035105be13622b005 /kernel/locking
parenta9668cd6ee288c4838bc668880ac085be551cac2 (diff)
downloadlinux-d92a8cfcb37ecd1315269dab741f073b63b3a8b6.tar.xz
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>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/lockdep.c95
-rw-r--r--kernel/locking/lockdep_states.h1
2 files changed, 1 insertions, 95 deletions
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)