From bc015cb84129eb1451913cfebece270bf7a39e0f Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Wed, 19 Jan 2011 09:30:01 +0000 Subject: GFS2: Use RCU for glock hash table This has a number of advantages: - Reduces contention on the hash table lock - Makes the code smaller and simpler - Should speed up glock dumps when under load - Removes ref count changing in examine_bucket - No longer need hash chain lock in glock_put() in common case There are some further changes which this enables and which we may do in the future. One is to look at using SLAB_RCU, and another is to look at using a per-cpu counter for the per-sb glock counter, since that is touched twice in the lifetime of each glock (but only used at umount time). Signed-off-by: Steven Whitehouse Cc: Paul E. McKenney --- fs/gfs2/glock.c | 390 +++++++++++++++++++++----------------------------------- 1 file changed, 147 insertions(+), 243 deletions(-) (limited to 'fs/gfs2/glock.c') diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 08a8beb152e6..c75d4998519e 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -26,6 +26,9 @@ #include #include #include +#include +#include +#include #include "gfs2.h" #include "incore.h" @@ -41,10 +44,6 @@ #define CREATE_TRACE_POINTS #include "trace_gfs2.h" -struct gfs2_gl_hash_bucket { - struct hlist_head hb_list; -}; - struct gfs2_glock_iter { int hash; /* hash bucket index */ struct gfs2_sbd *sdp; /* incore superblock */ @@ -54,7 +53,6 @@ struct gfs2_glock_iter { typedef void (*glock_examiner) (struct gfs2_glock * gl); -static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); @@ -70,57 +68,9 @@ static DEFINE_SPINLOCK(lru_lock); #define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT) #define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1) -static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE]; +static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE]; static struct dentry *gfs2_root; -/* - * Despite what you might think, the numbers below are not arbitrary :-) - * They are taken from the ipv4 routing hash code, which is well tested - * and thus should be nearly optimal. Later on we might tweek the numbers - * but for now this should be fine. - * - * The reason for putting the locks in a separate array from the list heads - * is that we can have fewer locks than list heads and save memory. We use - * the same hash function for both, but with a different hash mask. - */ -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ - defined(CONFIG_PROVE_LOCKING) - -#ifdef CONFIG_LOCKDEP -# define GL_HASH_LOCK_SZ 256 -#else -# if NR_CPUS >= 32 -# define GL_HASH_LOCK_SZ 4096 -# elif NR_CPUS >= 16 -# define GL_HASH_LOCK_SZ 2048 -# elif NR_CPUS >= 8 -# define GL_HASH_LOCK_SZ 1024 -# elif NR_CPUS >= 4 -# define GL_HASH_LOCK_SZ 512 -# else -# define GL_HASH_LOCK_SZ 256 -# endif -#endif - -/* We never want more locks than chains */ -#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ -# undef GL_HASH_LOCK_SZ -# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE -#endif - -static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ]; - -static inline rwlock_t *gl_lock_addr(unsigned int x) -{ - return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)]; -} -#else /* not SMP, so no spinlocks required */ -static inline rwlock_t *gl_lock_addr(unsigned int x) -{ - return NULL; -} -#endif - /** * gl_hash() - Turn glock number into hash bucket number * @lock: The glock number @@ -141,25 +91,30 @@ static unsigned int gl_hash(const struct gfs2_sbd *sdp, return h; } -/** - * glock_free() - Perform a few checks and then release struct gfs2_glock - * @gl: The glock to release - * - * Also calls lock module to release its internal structure for this glock. - * - */ +static inline void spin_lock_bucket(unsigned int hash) +{ + struct hlist_bl_head *bl = &gl_hash_table[hash]; + bit_spin_lock(0, (unsigned long *)bl); +} + +static inline void spin_unlock_bucket(unsigned int hash) +{ + struct hlist_bl_head *bl = &gl_hash_table[hash]; + __bit_spin_unlock(0, (unsigned long *)bl); +} -static void glock_free(struct gfs2_glock *gl) +void gfs2_glock_free(struct rcu_head *rcu) { + struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); struct gfs2_sbd *sdp = gl->gl_sbd; - struct address_space *mapping = gfs2_glock2aspace(gl); - struct kmem_cache *cachep = gfs2_glock_cachep; - GLOCK_BUG_ON(gl, mapping && mapping->nrpages); - trace_gfs2_glock_put(gl); - if (mapping) - cachep = gfs2_glock_aspace_cachep; - sdp->sd_lockstruct.ls_ops->lm_put_lock(cachep, gl); + if (gl->gl_ops->go_flags & GLOF_ASPACE) + kmem_cache_free(gfs2_glock_aspace_cachep, gl); + else + kmem_cache_free(gfs2_glock_cachep, gl); + + if (atomic_dec_and_test(&sdp->sd_glock_disposal)) + wake_up(&sdp->sd_glock_wait); } /** @@ -185,34 +140,49 @@ static int demote_ok(const struct gfs2_glock *gl) { const struct gfs2_glock_operations *glops = gl->gl_ops; + /* assert_spin_locked(&gl->gl_spin); */ + if (gl->gl_state == LM_ST_UNLOCKED) return 0; - if (!list_empty(&gl->gl_holders)) + if (test_bit(GLF_LFLUSH, &gl->gl_flags)) + return 0; + if ((gl->gl_name.ln_type != LM_TYPE_INODE) && + !list_empty(&gl->gl_holders)) return 0; if (glops->go_demote_ok) return glops->go_demote_ok(gl); return 1; } + /** - * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list + * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list * @gl: the glock * + * If the glock is demotable, then we add it (or move it) to the end + * of the glock LRU list. */ -static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) +static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) { - int may_reclaim; - may_reclaim = (demote_ok(gl) && - (atomic_read(&gl->gl_ref) == 1 || - (gl->gl_name.ln_type == LM_TYPE_INODE && - atomic_read(&gl->gl_ref) <= 2))); - spin_lock(&lru_lock); - if (list_empty(&gl->gl_lru) && may_reclaim) { + if (demote_ok(gl)) { + spin_lock(&lru_lock); + + if (!list_empty(&gl->gl_lru)) + list_del_init(&gl->gl_lru); + else + atomic_inc(&lru_count); + list_add_tail(&gl->gl_lru, &lru_list); - atomic_inc(&lru_count); + spin_unlock(&lru_lock); } - spin_unlock(&lru_lock); +} + +void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) +{ + spin_lock(&gl->gl_spin); + __gfs2_glock_schedule_for_reclaim(gl); + spin_unlock(&gl->gl_spin); } /** @@ -227,7 +197,6 @@ void gfs2_glock_put_nolock(struct gfs2_glock *gl) { if (atomic_dec_and_test(&gl->gl_ref)) GLOCK_BUG_ON(gl, 1); - gfs2_glock_schedule_for_reclaim(gl); } /** @@ -236,30 +205,26 @@ void gfs2_glock_put_nolock(struct gfs2_glock *gl) * */ -int gfs2_glock_put(struct gfs2_glock *gl) +void gfs2_glock_put(struct gfs2_glock *gl) { - int rv = 0; + struct gfs2_sbd *sdp = gl->gl_sbd; + struct address_space *mapping = gfs2_glock2aspace(gl); - write_lock(gl_lock_addr(gl->gl_hash)); - if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) { - hlist_del(&gl->gl_list); + if (atomic_dec_and_test(&gl->gl_ref)) { + spin_lock_bucket(gl->gl_hash); + hlist_bl_del_rcu(&gl->gl_list); + spin_unlock_bucket(gl->gl_hash); + spin_lock(&lru_lock); if (!list_empty(&gl->gl_lru)) { list_del_init(&gl->gl_lru); atomic_dec(&lru_count); } spin_unlock(&lru_lock); - write_unlock(gl_lock_addr(gl->gl_hash)); GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); - glock_free(gl); - rv = 1; - goto out; + GLOCK_BUG_ON(gl, mapping && mapping->nrpages); + trace_gfs2_glock_put(gl); + sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); } - spin_lock(&gl->gl_spin); - gfs2_glock_schedule_for_reclaim(gl); - spin_unlock(&gl->gl_spin); - write_unlock(gl_lock_addr(gl->gl_hash)); -out: - return rv; } /** @@ -275,17 +240,15 @@ static struct gfs2_glock *search_bucket(unsigned int hash, const struct lm_lockname *name) { struct gfs2_glock *gl; - struct hlist_node *h; + struct hlist_bl_node *h; - hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) { + hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) { if (!lm_name_equal(&gl->gl_name, name)) continue; if (gl->gl_sbd != sdp) continue; - - atomic_inc(&gl->gl_ref); - - return gl; + if (atomic_inc_not_zero(&gl->gl_ref)) + return gl; } return NULL; @@ -743,10 +706,11 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, struct gfs2_glock *gl, *tmp; unsigned int hash = gl_hash(sdp, &name); struct address_space *mapping; + struct kmem_cache *cachep; - read_lock(gl_lock_addr(hash)); + rcu_read_lock(); gl = search_bucket(hash, sdp, &name); - read_unlock(gl_lock_addr(hash)); + rcu_read_unlock(); *glp = gl; if (gl) @@ -755,9 +719,10 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, return -ENOENT; if (glops->go_flags & GLOF_ASPACE) - gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL); + cachep = gfs2_glock_aspace_cachep; else - gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); + cachep = gfs2_glock_cachep; + gl = kmem_cache_alloc(cachep, GFP_KERNEL); if (!gl) return -ENOMEM; @@ -790,15 +755,15 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, mapping->writeback_index = 0; } - write_lock(gl_lock_addr(hash)); + spin_lock_bucket(hash); tmp = search_bucket(hash, sdp, &name); if (tmp) { - write_unlock(gl_lock_addr(hash)); - glock_free(gl); + spin_unlock_bucket(hash); + kmem_cache_free(cachep, gl); gl = tmp; } else { - hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list); - write_unlock(gl_lock_addr(hash)); + hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]); + spin_unlock_bucket(hash); } *glp = gl; @@ -1113,6 +1078,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh) !test_bit(GLF_DEMOTE, &gl->gl_flags)) fast_path = 1; } + __gfs2_glock_schedule_for_reclaim(gl); trace_gfs2_glock_queue(gh, 0); spin_unlock(&gl->gl_spin); if (likely(fast_path)) @@ -1440,42 +1406,30 @@ static struct shrinker glock_shrinker = { * @sdp: the filesystem * @bucket: the bucket * - * Returns: 1 if the bucket has entries */ -static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, +static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp, unsigned int hash) { - struct gfs2_glock *gl, *prev = NULL; - int has_entries = 0; - struct hlist_head *head = &gl_hash_table[hash].hb_list; + struct gfs2_glock *gl; + struct hlist_bl_head *head = &gl_hash_table[hash]; + struct hlist_bl_node *pos; - read_lock(gl_lock_addr(hash)); - /* Can't use hlist_for_each_entry - don't want prefetch here */ - if (hlist_empty(head)) - goto out; - gl = list_entry(head->first, struct gfs2_glock, gl_list); - while(1) { - if (!sdp || gl->gl_sbd == sdp) { - gfs2_glock_hold(gl); - read_unlock(gl_lock_addr(hash)); - if (prev) - gfs2_glock_put(prev); - prev = gl; + rcu_read_lock(); + hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) { + if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref)) examiner(gl); - has_entries = 1; - read_lock(gl_lock_addr(hash)); - } - if (gl->gl_list.next == NULL) - break; - gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list); } -out: - read_unlock(gl_lock_addr(hash)); - if (prev) - gfs2_glock_put(prev); + rcu_read_unlock(); cond_resched(); - return has_entries; +} + +static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) +{ + unsigned x; + + for (x = 0; x < GFS2_GL_HASH_SIZE; x++) + examine_bucket(examiner, sdp, x); } @@ -1529,10 +1483,21 @@ static void clear_glock(struct gfs2_glock *gl) void gfs2_glock_thaw(struct gfs2_sbd *sdp) { - unsigned x; + glock_hash_walk(thaw_glock, sdp); +} - for (x = 0; x < GFS2_GL_HASH_SIZE; x++) - examine_bucket(thaw_glock, sdp, x); +static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) +{ + int ret; + spin_lock(&gl->gl_spin); + ret = __dump_glock(seq, gl); + spin_unlock(&gl->gl_spin); + return ret; +} + +static void dump_glock_func(struct gfs2_glock *gl) +{ + dump_glock(NULL, gl); } /** @@ -1545,13 +1510,10 @@ void gfs2_glock_thaw(struct gfs2_sbd *sdp) void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) { - unsigned int x; - - for (x = 0; x < GFS2_GL_HASH_SIZE; x++) - examine_bucket(clear_glock, sdp, x); + glock_hash_walk(clear_glock, sdp); flush_workqueue(glock_workqueue); wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0); - gfs2_dump_lockstate(sdp); + glock_hash_walk(dump_glock_func, sdp); } void gfs2_glock_finish_truncate(struct gfs2_inode *ip) @@ -1717,66 +1679,15 @@ out: return error; } -static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) -{ - int ret; - spin_lock(&gl->gl_spin); - ret = __dump_glock(seq, gl); - spin_unlock(&gl->gl_spin); - return ret; -} - -/** - * gfs2_dump_lockstate - print out the current lockstate - * @sdp: the filesystem - * @ub: the buffer to copy the information into - * - * If @ub is NULL, dump the lockstate to the console. - * - */ - -static int gfs2_dump_lockstate(struct gfs2_sbd *sdp) -{ - struct gfs2_glock *gl; - struct hlist_node *h; - unsigned int x; - int error = 0; - - for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { - - read_lock(gl_lock_addr(x)); - - hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) { - if (gl->gl_sbd != sdp) - continue; - - error = dump_glock(NULL, gl); - if (error) - break; - } - - read_unlock(gl_lock_addr(x)); - - if (error) - break; - } - - return error; -} int __init gfs2_glock_init(void) { unsigned i; for(i = 0; i < GFS2_GL_HASH_SIZE; i++) { - INIT_HLIST_HEAD(&gl_hash_table[i].hb_list); - } -#ifdef GL_HASH_LOCK_SZ - for(i = 0; i < GL_HASH_LOCK_SZ; i++) { - rwlock_init(&gl_hash_locks[i]); + INIT_HLIST_BL_HEAD(&gl_hash_table[i]); } -#endif glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_FREEZEABLE, 0); @@ -1802,62 +1713,54 @@ void gfs2_glock_exit(void) destroy_workqueue(gfs2_delete_workqueue); } +static inline struct gfs2_glock *glock_hash_chain(unsigned hash) +{ + return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]), + struct gfs2_glock, gl_list); +} + +static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl) +{ + return hlist_bl_entry(rcu_dereference_raw(gl->gl_list.next), + struct gfs2_glock, gl_list); +} + static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) { struct gfs2_glock *gl; -restart: - read_lock(gl_lock_addr(gi->hash)); - gl = gi->gl; - if (gl) { - gi->gl = hlist_entry(gl->gl_list.next, - struct gfs2_glock, gl_list); - } else { - gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, - struct gfs2_glock, gl_list); - } - if (gi->gl) - gfs2_glock_hold(gi->gl); - read_unlock(gl_lock_addr(gi->hash)); - if (gl) - gfs2_glock_put(gl); - while (gi->gl == NULL) { - gi->hash++; - if (gi->hash >= GFS2_GL_HASH_SIZE) - return 1; - read_lock(gl_lock_addr(gi->hash)); - gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first, - struct gfs2_glock, gl_list); - if (gi->gl) - gfs2_glock_hold(gi->gl); - read_unlock(gl_lock_addr(gi->hash)); - } - - if (gi->sdp != gi->gl->gl_sbd) - goto restart; + do { + gl = gi->gl; + if (gl) { + gi->gl = glock_hash_next(gl); + } else { + gi->gl = glock_hash_chain(gi->hash); + } + while (gi->gl == NULL) { + gi->hash++; + if (gi->hash >= GFS2_GL_HASH_SIZE) { + rcu_read_unlock(); + return 1; + } + gi->gl = glock_hash_chain(gi->hash); + } + /* Skip entries for other sb and dead entries */ + } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0); return 0; } -static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) -{ - if (gi->gl) - gfs2_glock_put(gi->gl); - gi->gl = NULL; -} - static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) { struct gfs2_glock_iter *gi = seq->private; loff_t n = *pos; gi->hash = 0; + rcu_read_lock(); do { - if (gfs2_glock_iter_next(gi)) { - gfs2_glock_iter_free(gi); + if (gfs2_glock_iter_next(gi)) return NULL; - } } while (n--); return gi->gl; @@ -1870,10 +1773,8 @@ static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, (*pos)++; - if (gfs2_glock_iter_next(gi)) { - gfs2_glock_iter_free(gi); + if (gfs2_glock_iter_next(gi)) return NULL; - } return gi->gl; } @@ -1881,7 +1782,10 @@ static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) { struct gfs2_glock_iter *gi = seq->private; - gfs2_glock_iter_free(gi); + + if (gi->gl) + rcu_read_unlock(); + gi->gl = NULL; } static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) -- cgit v1.2.3 From edae38a6431276c50d4b51543c36de258722358e Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 31 Jan 2011 09:38:12 +0000 Subject: GFS2: Fix glock queue trace point Somehow this tracepoint landed up in the wrong place. This moves it to where it should be. Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/gfs2/glock.c') diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index c75d4998519e..ddc3e1e3faaf 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -972,13 +972,13 @@ fail: insert_pt = &gh2->gh_list; } set_bit(GLF_QUEUED, &gl->gl_flags); + trace_gfs2_glock_queue(gh, 1); if (likely(insert_pt == NULL)) { list_add_tail(&gh->gh_list, &gl->gl_holders); if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) goto do_cancel; return; } - trace_gfs2_glock_queue(gh, 1); list_add_tail(&gh->gh_list, insert_pt); do_cancel: gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); -- cgit v1.2.3 From fc0e38dae645f65424d1fb5d2a938aab8ce48a58 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Wed, 9 Mar 2011 10:58:04 +0000 Subject: GFS2: Fix glock deallocation race This patch fixes a race in deallocating glocks which was introduced in the RCU glock patch. We need to ensure that the glock count is kept correct even in the case that there is a race to add a new glock into the hash table. Also, to avoid having to wait for an RCU grace period, the glock counter can be decremented before call_rcu() is called. Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.c | 10 ++++++++-- fs/gfs2/glock.h | 2 +- fs/gfs2/lock_dlm.c | 4 ++-- fs/gfs2/ops_fstype.c | 7 +------ 4 files changed, 12 insertions(+), 11 deletions(-) (limited to 'fs/gfs2/glock.c') diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index ddc3e1e3faaf..3f45a14009b8 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -103,16 +103,21 @@ static inline void spin_unlock_bucket(unsigned int hash) __bit_spin_unlock(0, (unsigned long *)bl); } -void gfs2_glock_free(struct rcu_head *rcu) +static void gfs2_glock_dealloc(struct rcu_head *rcu) { struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); - struct gfs2_sbd *sdp = gl->gl_sbd; if (gl->gl_ops->go_flags & GLOF_ASPACE) kmem_cache_free(gfs2_glock_aspace_cachep, gl); else kmem_cache_free(gfs2_glock_cachep, gl); +} + +void gfs2_glock_free(struct gfs2_glock *gl) +{ + struct gfs2_sbd *sdp = gl->gl_sbd; + call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); if (atomic_dec_and_test(&sdp->sd_glock_disposal)) wake_up(&sdp->sd_glock_wait); } @@ -760,6 +765,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, if (tmp) { spin_unlock_bucket(hash); kmem_cache_free(cachep, gl); + atomic_dec(&sdp->sd_glock_disposal); gl = tmp; } else { hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]); diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h index afa8bfea5647..aea160690e94 100644 --- a/fs/gfs2/glock.h +++ b/fs/gfs2/glock.h @@ -230,7 +230,7 @@ extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp); extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip); extern void gfs2_glock_thaw(struct gfs2_sbd *sdp); extern void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl); -extern void gfs2_glock_free(struct rcu_head *rcu); +extern void gfs2_glock_free(struct gfs2_glock *gl); extern int __init gfs2_glock_init(void); extern void gfs2_glock_exit(void); diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c index c80485cb6f25..98c80d8c2a62 100644 --- a/fs/gfs2/lock_dlm.c +++ b/fs/gfs2/lock_dlm.c @@ -30,7 +30,7 @@ static void gdlm_ast(void *arg) switch (gl->gl_lksb.sb_status) { case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */ - call_rcu(&gl->gl_rcu, gfs2_glock_free); + gfs2_glock_free(gl); return; case -DLM_ECANCEL: /* Cancel while getting lock */ ret |= LM_OUT_CANCELED; @@ -165,7 +165,7 @@ static void gdlm_put_lock(struct gfs2_glock *gl) int error; if (gl->gl_lksb.sb_lkid == 0) { - call_rcu(&gl->gl_rcu, gfs2_glock_free); + gfs2_glock_free(gl); return; } diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index a39c103ba499..67654d0ba15e 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -928,14 +928,9 @@ static const match_table_t nolock_tokens = { { Opt_err, NULL }, }; -static void nolock_put_lock(struct gfs2_glock *gl) -{ - call_rcu(&gl->gl_rcu, gfs2_glock_free); -} - static const struct lm_lockops nolock_ops = { .lm_proto_name = "lock_nolock", - .lm_put_lock = nolock_put_lock, + .lm_put_lock = gfs2_glock_free, .lm_tokens = &nolock_tokens, }; -- cgit v1.2.3 From fa1bbdea300a15ec7c1186a5e53de33a5b1672f5 Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Thu, 10 Mar 2011 11:41:57 -0500 Subject: GFS2: Optimize glock multiple-dequeue code This is a small patch that optimizes multiple glock dequeue operations. It changes the unlock order to be more efficient and makes it easier for lock debugging tools to unravel. It also eliminates the need for the temp variable x, although that would likely be optimized out. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'fs/gfs2/glock.c') diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 3f45a14009b8..8648409be451 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1248,10 +1248,8 @@ int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) { - unsigned int x; - - for (x = 0; x < num_gh; x++) - gfs2_glock_dq(&ghs[x]); + while (num_gh--) + gfs2_glock_dq(&ghs[num_gh]); } /** @@ -1263,10 +1261,8 @@ void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) { - unsigned int x; - - for (x = 0; x < num_gh; x++) - gfs2_glock_dq_uninit(&ghs[x]); + while (num_gh--) + gfs2_glock_dq_uninit(&ghs[num_gh]); } void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) -- cgit v1.2.3 From 7e32d02613a72a39ba01638337c609a9a866c653 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 15 Mar 2011 08:32:14 +0000 Subject: GFS2: Don't use _raw version of RCU dereference As per RCU glock patch review comments, don't use the _raw version of this function here. Signed-off-by: Steven Whitehouse Cc: Paul E. McKenney Reviewed-by: Paul E. McKenney --- fs/gfs2/glock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/gfs2/glock.c') diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 8648409be451..85044b418249 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1723,7 +1723,7 @@ static inline struct gfs2_glock *glock_hash_chain(unsigned hash) static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl) { - return hlist_bl_entry(rcu_dereference_raw(gl->gl_list.next), + return hlist_bl_entry(rcu_dereference(gl->gl_list.next), struct gfs2_glock, gl_list); } -- cgit v1.2.3