quota: Convert quota statistics to generic percpu_counter
Generic per-cpu counter has some memory overhead but it is negligible for
modern systems and embedded systems compile without quota support. And code
reuse is a good thing. This patch should fix complain from preemptive kernels
which was introduced by dde9588853b1bde.
[Jan Kara: Fixed patch to work on 32-bit archs as well]
Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 1ff9131..531dee6 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -228,10 +228,6 @@
struct dqstats dqstats;
EXPORT_SYMBOL(dqstats);
-#ifdef CONFIG_SMP
-struct dqstats *dqstats_pcpu;
-EXPORT_SYMBOL(dqstats_pcpu);
-#endif
static qsize_t inode_get_rsv_space(struct inode *inode);
static void __dquot_initialize(struct inode *inode, int type);
@@ -676,27 +672,10 @@
}
}
-static int dqstats_read(unsigned int type)
-{
- int count = 0;
-#ifdef CONFIG_SMP
- int cpu;
- for_each_possible_cpu(cpu)
- count += per_cpu_ptr(dqstats_pcpu, cpu)->stat[type];
- /* Statistics reading is racy, but absolute accuracy isn't required */
- if (count < 0)
- count = 0;
-#else
- count = dqstats.stat[type];
-#endif
- return count;
-}
-
/*
* This is called from kswapd when we think we need some
* more memory
*/
-
static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
{
if (nr) {
@@ -704,7 +683,9 @@
prune_dqcache(nr);
spin_unlock(&dq_list_lock);
}
- return (dqstats_read(DQST_FREE_DQUOTS)/100) * sysctl_vfs_cache_pressure;
+ return ((unsigned)
+ percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
+ /100) * sysctl_vfs_cache_pressure;
}
static struct shrinker dqcache_shrinker = {
@@ -2497,11 +2478,11 @@
static int do_proc_dqstats(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
-#ifdef CONFIG_SMP
- /* Update global table */
unsigned int type = (int *)table->data - dqstats.stat;
- dqstats.stat[type] = dqstats_read(type);
-#endif
+
+ /* Update global table */
+ dqstats.stat[type] =
+ percpu_counter_sum_positive(&dqstats.counter[type]);
return proc_dointvec(table, write, buffer, lenp, ppos);
}
@@ -2594,7 +2575,7 @@
static int __init dquot_init(void)
{
- int i;
+ int i, ret;
unsigned long nr_hash, order;
printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
@@ -2612,12 +2593,11 @@
if (!dquot_hash)
panic("Cannot create dquot hash table");
-#ifdef CONFIG_SMP
- dqstats_pcpu = alloc_percpu(struct dqstats);
- if (!dqstats_pcpu)
- panic("Cannot create dquot stats table");
-#endif
- memset(&dqstats, 0, sizeof(struct dqstats));
+ for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
+ ret = percpu_counter_init(&dqstats.counter[i], 0);
+ if (ret)
+ panic("Cannot create dquot stat counters");
+ }
/* Find power-of-two hlist_heads which can fit into allocation */
nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);