From: Yu Kuai <yukuai1@huaweicloud.com>
To: xni@redhat.com, paul.e.luse@linux.intel.com, song@kernel.org,
neilb@suse.com, shli@fb.com
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com,
yangerkun@huawei.com
Subject: [PATCH md-6.9 v4 03/11] md/raid1: record nonrot rdevs while adding/removing rdevs to conf
Date: Thu, 29 Feb 2024 17:57:06 +0800 [thread overview]
Message-ID: <20240229095714.926789-4-yukuai1@huaweicloud.com> (raw)
In-Reply-To: <20240229095714.926789-1-yukuai1@huaweicloud.com>
From: Yu Kuai <yukuai3@huawei.com>
For raid1, each read will iterate all the rdevs from conf and check if
any rdev is non-rotational, then choose rdev with minimal IO inflight
if so, or rdev with closest distance otherwise.
Disk nonrot info can be changed through sysfs entry:
/sys/block/[disk_name]/queue/rotational
However, consider that this should only be used for testing, and user
really shouldn't do this in real life. Record the number of non-rotational
disks in conf, to avoid checking each rdev in IO fast path and simplify
read_balance() a little bit.
Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com>
Signed-off-by: Paul Luse <paul.e.luse@linux.intel.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
drivers/md/md.h | 1 +
drivers/md/raid1.c | 17 ++++++++++-------
drivers/md/raid1.h | 1 +
3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index a49ab04ab707..b2076a165c10 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -207,6 +207,7 @@ enum flag_bits {
* check if there is collision between raid1
* serial bios.
*/
+ Nonrot, /* non-rotational device (SSD) */
};
static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6ec9998f6257..de6ea87d4d24 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -599,7 +599,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
int sectors;
int best_good_sectors;
int best_disk, best_dist_disk, best_pending_disk;
- int has_nonrot_disk;
int disk;
sector_t best_dist;
unsigned int min_pending;
@@ -620,7 +619,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
best_pending_disk = -1;
min_pending = UINT_MAX;
best_good_sectors = 0;
- has_nonrot_disk = 0;
choose_next_idle = 0;
clear_bit(R1BIO_FailFast, &r1_bio->state);
@@ -637,7 +635,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
sector_t first_bad;
int bad_sectors;
unsigned int pending;
- bool nonrot;
rdev = conf->mirrors[disk].rdev;
if (r1_bio->bios[disk] == IO_BLOCKED
@@ -703,8 +700,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
/* At least two disks to choose from so failfast is OK */
set_bit(R1BIO_FailFast, &r1_bio->state);
- nonrot = bdev_nonrot(rdev->bdev);
- has_nonrot_disk |= nonrot;
pending = atomic_read(&rdev->nr_pending);
dist = abs(this_sector - conf->mirrors[disk].head_position);
if (choose_first) {
@@ -731,7 +726,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
* small, but not a big deal since when the second disk
* starts IO, the first disk is likely still busy.
*/
- if (nonrot && opt_iosize > 0 &&
+ if (test_bit(Nonrot, &rdev->flags) && opt_iosize > 0 &&
mirror->seq_start != MaxSector &&
mirror->next_seq_sect > opt_iosize &&
mirror->next_seq_sect - opt_iosize >=
@@ -763,7 +758,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
* mixed ratation/non-rotational disks depending on workload.
*/
if (best_disk == -1) {
- if (has_nonrot_disk || min_pending == 0)
+ if (READ_ONCE(conf->nonrot_disks) || min_pending == 0)
best_disk = best_pending_disk;
else
best_disk = best_dist_disk;
@@ -1768,6 +1763,11 @@ static bool raid1_add_conf(struct r1conf *conf, struct md_rdev *rdev, int disk,
if (info->rdev)
return false;
+ if (bdev_nonrot(rdev->bdev)) {
+ set_bit(Nonrot, &rdev->flags);
+ WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks + 1);
+ }
+
rdev->raid_disk = disk;
info->head_position = 0;
info->seq_start = MaxSector;
@@ -1791,6 +1791,9 @@ static bool raid1_remove_conf(struct r1conf *conf, int disk)
rdev->mddev->degraded < conf->raid_disks)
return false;
+ if (test_and_clear_bit(Nonrot, &rdev->flags))
+ WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks - 1);
+
WRITE_ONCE(info->rdev, NULL);
return true;
}
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index 14d4211a123a..5300cbaa58a4 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -71,6 +71,7 @@ struct r1conf {
* allow for replacements.
*/
int raid_disks;
+ int nonrot_disks;
spinlock_t device_lock;
--
2.39.2
next prev parent reply other threads:[~2024-02-29 10:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-29 9:57 [PATCH md-6.9 v4 00/11] md/raid1: refactor read_balance() and some minor fix Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 01/11] md: add a new helper rdev_has_badblock() Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 02/11] md/raid1: factor out helpers to add rdev to conf Yu Kuai
2024-02-29 9:57 ` Yu Kuai [this message]
2024-02-29 16:37 ` [PATCH md-6.9 v4 03/11] md/raid1: record nonrot rdevs while adding/removing rdevs " Paul Menzel
2024-03-01 1:59 ` Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 04/11] md/raid1: fix choose next idle in read_balance() Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 05/11] md/raid1-10: add a helper raid1_check_read_range() Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 06/11] md/raid1-10: factor out a new helper raid1_should_read_first() Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 07/11] md/raid1: factor out read_first_rdev() from read_balance() Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 08/11] md/raid1: factor out choose_slow_rdev() " Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 09/11] md/raid1: factor out choose_bb_rdev() " Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 10/11] md/raid1: factor out the code to manage sequential IO Yu Kuai
2024-02-29 9:57 ` [PATCH md-6.9 v4 11/11] md/raid1: factor out helpers to choose the best rdev from read_balance() Yu Kuai
2024-03-01 7:16 ` [PATCH md-6.9 v4 00/11] md/raid1: refactor read_balance() and some minor fix Song Liu
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