Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f32764bd authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Jan Kara
Browse files

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 dde95888.

[Jan Kara: Fixed patch to work on 32-bit archs as well]

Reported-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 1513b02c

fs/quota/dquot.c

+13 −33
Original line number Diff line number Diff line
@@ -228,10 +228,6 @@ static struct hlist_head *dquot_hash; 


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 void prune_dqcache(int count) 
	}

}



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 @@ static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 
		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 @@ EXPORT_SYMBOL(dquot_quotactl_ops); 
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 ctl_table sys_table[] = { 


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 @@ static int __init dquot_init(void) 
	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);

include/linux/quota.h

+4 −12
Original line number Diff line number Diff line
@@ -174,8 +174,7 @@ enum { 
#include <linux/rwsem.h>

#include <linux/spinlock.h>

#include <linux/wait.h>

#include <linux/percpu.h>

#include <linux/smp.h>

#include <linux/percpu_counter.h>



#include <linux/dqblk_xfs.h>

#include <linux/dqblk_v1.h>
@@ -254,6 +253,7 @@ enum { 


struct dqstats {

	int stat[_DQST_DQSTAT_LAST];

	struct percpu_counter counter[_DQST_DQSTAT_LAST];

};



extern struct dqstats *dqstats_pcpu;
@@ -261,20 +261,12 @@ extern struct dqstats dqstats; 


static inline void dqstats_inc(unsigned int type)

{

#ifdef CONFIG_SMP

	per_cpu_ptr(dqstats_pcpu, smp_processor_id())->stat[type]++;

#else

	dqstats.stat[type]++;

#endif

	percpu_counter_inc(&dqstats.counter[type]);

}



static inline void dqstats_dec(unsigned int type)

{

#ifdef CONFIG_SMP

	per_cpu_ptr(dqstats_pcpu, smp_processor_id())->stat[type]--;

#else

	dqstats.stat[type]--;

#endif

	percpu_counter_dec(&dqstats.counter[type]);

}



#define DQ_MOD_B	0	/* dquot modified since read */