Hi Kuai
I added some logs to check and add_bound_rdev can't be called when
creating raid device. Maybe move rdev_update_nonrot to
bind_rdev_to_array?
Regards
Xiao
On Thu, Feb 22, 2024 at 4:04 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> For raid1/raid10, 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 mddev, to avoid checking each rdev in IO fast path and simplify
> read_balance() a little bit.
>
> Co-developed-by: Paul Luse <paul.e.luse@xxxxxxxxxxxxxxx>
> Signed-off-by: Paul Luse <paul.e.luse@xxxxxxxxxxxxxxx>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> drivers/md/md.c | 28 ++++++++++++++++++++++++++--
> drivers/md/md.h | 2 ++
> drivers/md/raid1.c | 9 ++-------
> drivers/md/raid10.c | 8 ++------
> 4 files changed, 32 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index e2a5f513dbb7..9e671eec9309 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -146,6 +146,24 @@ static inline int speed_max(struct mddev *mddev)
> mddev->sync_speed_max : sysctl_speed_limit_max;
> }
>
> +static void rdev_update_nonrot(struct md_rdev *rdev)
> +{
> + if (!bdev_nonrot(rdev->bdev))
> + return;
> +
> + set_bit(Nonrot, &rdev->flags);
> + WRITE_ONCE(rdev->mddev->nonrot_disks, rdev->mddev->nonrot_disks + 1);
> +}
> +
> +static void rdev_clear_nonrot(struct md_rdev *rdev)
> +{
> + if (!test_bit(Nonrot, &rdev->flags))
> + return;
> +
> + clear_bit(Nonrot, &rdev->flags);
> + WRITE_ONCE(rdev->mddev->nonrot_disks, rdev->mddev->nonrot_disks - 1);
> +}
> +
> static void rdev_uninit_serial(struct md_rdev *rdev)
> {
> if (!test_and_clear_bit(CollisionCheck, &rdev->flags))
> @@ -2922,6 +2940,8 @@ static int add_bound_rdev(struct md_rdev *rdev)
> md_kick_rdev_from_array(rdev);
> return err;
> }
> +
> + rdev_update_nonrot(rdev);
> }
> sysfs_notify_dirent_safe(rdev->sysfs_state);
>
> @@ -3271,8 +3291,10 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
> if (err) {
> rdev->raid_disk = -1;
> return err;
> - } else
> - sysfs_notify_dirent_safe(rdev->sysfs_state);
> + }
> +
> + rdev_update_nonrot(rdev);
> + sysfs_notify_dirent_safe(rdev->sysfs_state);
> /* failure here is OK */;
> sysfs_link_rdev(rdev->mddev, rdev);
> /* don't wakeup anyone, leave that to userspace. */
> @@ -9266,6 +9288,7 @@ static int remove_and_add_spares(struct mddev *mddev,
> rdev_for_each(rdev, mddev) {
> if ((this == NULL || rdev == this) && rdev_removeable(rdev) &&
> !mddev->pers->hot_remove_disk(mddev, rdev)) {
> + rdev_clear_nonrot(rdev);
> sysfs_unlink_rdev(mddev, rdev);
> rdev->saved_raid_disk = rdev->raid_disk;
> rdev->raid_disk = -1;
> @@ -9289,6 +9312,7 @@ static int remove_and_add_spares(struct mddev *mddev,
> if (!test_bit(Journal, &rdev->flags))
> rdev->recovery_offset = 0;
> if (mddev->pers->hot_add_disk(mddev, rdev) == 0) {
> + rdev_update_nonrot(rdev);
> /* failure here is OK */
> sysfs_link_rdev(mddev, rdev);
> if (!test_bit(Journal, &rdev->flags))
> diff --git a/drivers/md/md.h b/drivers/md/md.h
> index a49ab04ab707..54aa951f2bba 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,
> @@ -312,6 +313,7 @@ struct mddev {
> unsigned long flags;
> unsigned long sb_flags;
>
> + int nonrot_disks;
> int suspended;
> struct mutex suspend_mutex;
> struct percpu_ref active_io;
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index a145fe48b9ce..c60ea58ae8c5 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 (conf->mddev->nonrot_disks || min_pending == 0)
> best_disk = best_pending_disk;
> else
> best_disk = best_dist_disk;
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index d5a7a621f0f0..1f6693e40e12 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -735,7 +735,6 @@ static struct md_rdev *read_balance(struct r10conf *conf,
> struct md_rdev *best_dist_rdev, *best_pending_rdev, *rdev = NULL;
> int do_balance;
> int best_dist_slot, best_pending_slot;
> - bool has_nonrot_disk = false;
> unsigned int min_pending;
> struct geom *geo = &conf->geo;
>
> @@ -766,7 +765,6 @@ static struct md_rdev *read_balance(struct r10conf *conf,
> int bad_sectors;
> sector_t dev_sector;
> unsigned int pending;
> - bool nonrot;
>
> if (r10_bio->devs[slot].bio == IO_BLOCKED)
> continue;
> @@ -818,10 +816,8 @@ static struct md_rdev *read_balance(struct r10conf *conf,
> if (!do_balance)
> break;
>
> - nonrot = bdev_nonrot(rdev->bdev);
> - has_nonrot_disk |= nonrot;
> pending = atomic_read(&rdev->nr_pending);
> - if (min_pending > pending && nonrot) {
> + if (min_pending > pending && test_bit(Nonrot, &rdev->flags)) {
> min_pending = pending;
> best_pending_slot = slot;
> best_pending_rdev = rdev;
> @@ -851,7 +847,7 @@ static struct md_rdev *read_balance(struct r10conf *conf,
> }
> }
> if (slot >= conf->copies) {
> - if (has_nonrot_disk) {
> + if (conf->mddev->nonrot_disks) {
> slot = best_pending_slot;
> rdev = best_pending_rdev;
> } else {
> --
> 2.39.2
>
>
