based on a patch by: Raz Ben-Jehuda(caro) <raziebe@xxxxxxxxx>
---
drivers/md/raid5.c | 92 +++++++++++++++++++++++++++++++++++++++++---
include/linux/raid/raid5.h | 5 ++
2 files changed, 90 insertions(+), 7 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 1a2d6b5..1b3db16 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -226,6 +226,8 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int
sh->sector = sector;
sh->pd_idx = pd_idx;
sh->state = 0;
+ sh->active_preread_jiffies = msecs_to_jiffies(
+ atomic_read(&conf->cache_policy->deadline_ms))+jiffies;
sh->disks = disks;
@@ -1172,6 +1174,7 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
+ sh->active_preread_jiffies = jiffies;
release_stripe(sh);
return 0;
}
@@ -1741,8 +1744,10 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
bip = &sh->dev[dd_idx].towrite;
if (*bip == NULL && sh->dev[dd_idx].written == NULL)
firstwrite = 1;
- } else
+ } else {
bip = &sh->dev[dd_idx].toread;
+ sh->active_preread_jiffies = jiffies;
+ }
while (*bip && (*bip)->bi_sector < bi->bi_sector) {
if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
goto overlap;
@@ -2160,7 +2165,7 @@ raid5_wt_cache_handle_new_writes(struct stripe_head *sh, struct stripe_head_stat
}
}
-static void raid5_wt_cache_activate_delayed(raid5_conf_t *conf)
+static struct stripe_head *raid5_wt_cache_activate_delayed(raid5_conf_t *conf)
{
struct stripe_cache_policy *cp = conf->cache_policy;
if (atomic_read(&cp->preread_active_stripes) < IO_THRESHOLD) {
@@ -2168,6 +2173,20 @@ static void raid5_wt_cache_activate_delayed(raid5_conf_t *conf)
struct list_head *l = cp->delayed_list.next;
struct stripe_head *sh;
sh = list_entry(l, struct stripe_head, lru);
+
+ if (time_before(jiffies,sh->active_preread_jiffies)) {
+ PRINTK("deadline: no expire sec=%lld %8u %8u\n",
+ (unsigned long long) sh->sector,
+ jiffies_to_msecs(sh->active_preread_jiffies),
+ jiffies_to_msecs(jiffies));
+ return sh;
+ } else {
+ PRINTK("deadline: expire:sec=%lld %8u %8u\n",
+ (unsigned long long)sh->sector,
+ jiffies_to_msecs(sh->active_preread_jiffies),
+ jiffies_to_msecs(jiffies));
+ }
+
list_del_init(l);
clear_bit(STRIPE_DELAYED, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
@@ -2175,9 +2194,11 @@ static void raid5_wt_cache_activate_delayed(raid5_conf_t *conf)
list_add_tail(&sh->lru, &conf->handle_list);
}
}
+
+ return NULL;
}
-static void raid5_wt_cache_raid5d(mddev_t *mddev, raid5_conf_t *conf)
+static struct stripe_head *raid5_wt_cache_raid5d(mddev_t *mddev, raid5_conf_t *conf)
{
struct stripe_cache_policy *cp = conf->cache_policy;
@@ -2185,7 +2206,9 @@ static void raid5_wt_cache_raid5d(mddev_t *mddev, raid5_conf_t *conf)
atomic_read(&cp->preread_active_stripes) < IO_THRESHOLD &&
!blk_queue_plugged(mddev->queue) &&
!list_empty(&cp->delayed_list))
- raid5_wt_cache_activate_delayed(conf);
+ return raid5_wt_cache_activate_delayed(conf);
+
+ return NULL;
}
static void raid5_wt_cache_init(raid5_conf_t *conf)
@@ -4339,7 +4362,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
*/
static void raid5d (mddev_t *mddev)
{
- struct stripe_head *sh;
+ struct stripe_head *sh,*delayed_sh=NULL;
raid5_conf_t *conf = mddev_to_conf(mddev);
int handled;
@@ -4363,7 +4386,10 @@ static void raid5d (mddev_t *mddev)
}
if (conf->cache_policy->raid5d)
- conf->cache_policy->raid5d(mddev, conf);
+ delayed_sh = conf->cache_policy->raid5d(mddev, conf);
+
+ if (delayed_sh)
+ break;
while ((bio = remove_bio_from_retry(conf))) {
int ok;
@@ -4401,8 +4427,60 @@ static void raid5d (mddev_t *mddev)
unplug_slaves(mddev);
PRINTK("--- raid5d inactive\n");
+
+ if (delayed_sh) {
+ unsigned long local_jiffies = jiffies, wakeup;
+ if (delayed_sh->active_preread_jiffies > local_jiffies) {
+ wakeup = delayed_sh->active_preread_jiffies - local_jiffies;
+ PRINTK("--- raid5d inactive sleep for %d\n",
+ jiffies_to_msecs(wakeup) );
+ mddev->thread->timeout = wakeup;
+ }
+ }
+}
+
+static ssize_t
+raid5_show_stripe_deadline(mddev_t *mddev, char *page)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ if (conf)
+ return sprintf(page, "%d\n",
+ atomic_read(&conf->cache_policy->deadline_ms));
+ else
+ return 0;
+}
+
+static ssize_t
+raid5_store_stripe_deadline(mddev_t *mddev, const char *page, size_t len)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ char *end;
+ int new;
+
+ if (len >= PAGE_SIZE)
+ return -EINVAL;
+ if (!conf)
+ return -ENODEV;
+
+ new = simple_strtoul(page, &end, 10);
+
+ if (!*page || (*end && *end != '\n') )
+ return -EINVAL;
+
+ if (new < 0 || new > 10000)
+ return -EINVAL;
+
+ atomic_set(&conf->cache_policy->deadline_ms,new);
+
+ return len;
}
+static struct md_sysfs_entry
+raid5_stripe_deadline = __ATTR(stripe_deadline, S_IRUGO | S_IWUSR,
+ raid5_show_stripe_deadline,
+ raid5_store_stripe_deadline);
+
+
static ssize_t
raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
{
@@ -4465,6 +4543,7 @@ raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
static struct attribute *raid5_attrs[] = {
&raid5_stripecache_size.attr,
&raid5_stripecache_active.attr,
+ &raid5_stripe_deadline.attr,
NULL,
};
static struct attribute_group raid5_attrs_group = {
@@ -4581,6 +4660,7 @@ static int run(mddev_t *mddev)
atomic_set(&conf->active_stripes, 0);
atomic_set(&conf->active_aligned_reads, 0);
conf->cache_policy->init(conf);
+ atomic_set(&conf->cache_policy->deadline_ms, 0);
PRINTK("raid5: run(%s) called.\n", mdname(mddev));
diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 560d460..d447807 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -166,6 +166,7 @@ struct stripe_head {
int bm_seq; /* sequence number for bitmap flushes */
int disks; /* disks in stripe */
int write_requests_pending;
+ unsigned long active_preread_jiffies;
struct stripe_operations {
unsigned long pending; /* pending operations (set for request->issue->complete) */
unsigned long ack; /* submitted operations (set for issue->complete */
@@ -353,7 +354,8 @@ struct stripe_cache_policy {
* wt: check for stripes that can be taken off the delayed list
* wb: n/a
*/
- void (*raid5d)(mddev_t *mddev, struct raid5_private_data *conf);
+ struct stripe_head *(*raid5d)(mddev_t *mddev,
+ struct raid5_private_data *conf);
/* init
* wt: initialize 'delayed_list' and 'preread_active_stripes'
* wb: initialize 'dirty_list' and 'dirty_stripes'
@@ -380,6 +382,7 @@ struct stripe_cache_policy {
atomic_t preread_active_stripes;
atomic_t evict_active_stripes;
};
+ atomic_t deadline_ms;
};
struct raid5_private_data {
-
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