diff --git a/fs/dcache.c b/fs/dcache.c index 6ef1c2e1bbc4a7a93a07a7a1f647ceca664b0778..03161240e744b30e32fcebd7dbf8f65d5f2eef21 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -147,8 +147,22 @@ struct dentry_stat_t dentry_stat = { }; static DEFINE_PER_CPU(long, nr_dentry); +static DEFINE_PER_CPU(long, nr_dentry_unused); #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) + +/* + * Here we resort to our own counters instead of using generic per-cpu counters + * for consistency with what the vfs inode code does. We are expected to harvest + * better code and performance by having our own specialized counters. + * + * Please note that the loop is done over all possible CPUs, not over all online + * CPUs. The reason for this is that we don't want to play games with CPUs going + * on and off. If one of them goes off, we will just keep their counters. + * + * glommer: See cffbc8a for details, and if you ever intend to change this, + * please update all vfs counters to match. + */ static long get_nr_dentry(void) { int i; @@ -158,10 +172,20 @@ static long get_nr_dentry(void) return sum < 0 ? 0 : sum; } +static long get_nr_dentry_unused(void) +{ + int i; + long sum = 0; + for_each_possible_cpu(i) + sum += per_cpu(nr_dentry_unused, i); + return sum < 0 ? 0 : sum; +} + int proc_nr_dentry(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { dentry_stat.nr_dentry = get_nr_dentry(); + dentry_stat.nr_unused = get_nr_dentry_unused(); return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } #endif @@ -342,7 +366,7 @@ static void dentry_lru_add(struct dentry *dentry) dentry->d_flags |= DCACHE_LRU_LIST; list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); dentry->d_sb->s_nr_dentry_unused++; - dentry_stat.nr_unused++; + this_cpu_inc(nr_dentry_unused); spin_unlock(&dcache_lru_lock); } } @@ -352,7 +376,7 @@ static void __dentry_lru_del(struct dentry *dentry) list_del_init(&dentry->d_lru); dentry->d_flags &= ~(DCACHE_SHRINK_LIST | DCACHE_LRU_LIST); dentry->d_sb->s_nr_dentry_unused--; - dentry_stat.nr_unused--; + this_cpu_dec(nr_dentry_unused); } /* @@ -374,7 +398,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list) dentry->d_flags |= DCACHE_LRU_LIST; list_add_tail(&dentry->d_lru, list); dentry->d_sb->s_nr_dentry_unused++; - dentry_stat.nr_unused++; + this_cpu_inc(nr_dentry_unused); } else { list_move_tail(&dentry->d_lru, list); }