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Commit b721420e authored by Shaohua Li's avatar Shaohua Li Committed by NeilBrown
Browse files

raid5: sysfs entry to control worker thread number 



Add a sysfs entry to control running workqueue thread number. If
group_thread_cnt is set to 0, we will disable workqueue offload handling of
stripes.

Signed-off-by: default avatarShaohua Li <shli@fusionio.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 851c30c9

drivers/md/raid5.c

+60 −0
Original line number Original line Diff line number Diff line
@@ -5145,10 +5145,70 @@ stripe_cache_active_show(struct mddev *mddev, char *page) 
static struct md_sysfs_entry

static struct md_sysfs_entry

raid5_stripecache_active = __ATTR_RO(stripe_cache_active);

raid5_stripecache_active = __ATTR_RO(stripe_cache_active);





static ssize_t

raid5_show_group_thread_cnt(struct mddev *mddev, char *page)

{

	struct r5conf *conf = mddev->private;

	if (conf)

		return sprintf(page, "%d\n", conf->worker_cnt_per_group);

	else

		return 0;

}



static int alloc_thread_groups(struct r5conf *conf, int cnt);

static ssize_t

raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)

{

	struct r5conf *conf = mddev->private;

	unsigned long new;

	int err;

	struct r5worker_group *old_groups;

	int old_group_cnt;



	if (len >= PAGE_SIZE)

		return -EINVAL;

	if (!conf)

		return -ENODEV;



	if (kstrtoul(page, 10, &new))

		return -EINVAL;



	if (new == conf->worker_cnt_per_group)

		return len;



	mddev_suspend(mddev);



	old_groups = conf->worker_groups;

	old_group_cnt = conf->worker_cnt_per_group;



	conf->worker_groups = NULL;

	err = alloc_thread_groups(conf, new);

	if (err) {

		conf->worker_groups = old_groups;

		conf->worker_cnt_per_group = old_group_cnt;

	} else {

		if (old_groups)

			kfree(old_groups[0].workers);

		kfree(old_groups);

	}



	mddev_resume(mddev);



	if (err)

		return err;

	return len;

}



static struct md_sysfs_entry

raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,

				raid5_show_group_thread_cnt,

				raid5_store_group_thread_cnt);



static struct attribute *raid5_attrs[] =  {

static struct attribute *raid5_attrs[] =  {

	&raid5_stripecache_size.attr,

	&raid5_stripecache_size.attr,

	&raid5_stripecache_active.attr,

	&raid5_stripecache_active.attr,

	&raid5_preread_bypass_threshold.attr,

	&raid5_preread_bypass_threshold.attr,

	&raid5_group_thread_cnt.attr,

	NULL,

	NULL,

};

};

static struct attribute_group raid5_attrs_group = {

static struct attribute_group raid5_attrs_group = {