From a022325ab970cf04b66ca128a87345714aa44b99 Mon Sep 17 00:00:00 2001
From: Yu Kuai <yukuai3@huawei.com>
Date: Mon, 29 May 2023 21:11:04 +0800
Subject: [PATCH] md/md-bitmap: add a new helper to unplug bitmap asynchrously
If bitmap is enabled, bitmap must update before submitting write io, this
is why unplug callback must move these io to 'conf->pending_io_list' if
'current->bio_list' is not empty, which will suffer performance
degradation.
A new helper md_bitmap_unplug_async() is introduced to submit bitmap io
in a kworker, so that submit bitmap io in raid10_unplug() doesn't require
that 'current->bio_list' is empty.
This patch prepare to limit the number of plugged bio.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-6-yukuai1@huaweicloud.com
---
drivers/md/md-bitmap.c | 29 +++++++++++++++++++++++++++++
drivers/md/md-bitmap.h | 1 +
drivers/md/md.c | 9 +++++++++
drivers/md/md.h | 1 +
4 files changed, 40 insertions(+)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 3ee590cf12a70..1ff712889a3b3 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1054,6 +1054,35 @@ void md_bitmap_unplug(struct bitmap *bitmap)
}
EXPORT_SYMBOL(md_bitmap_unplug);
+struct bitmap_unplug_work {
+ struct work_struct work;
+ struct bitmap *bitmap;
+ struct completion *done;
+};
+
+static void md_bitmap_unplug_fn(struct work_struct *work)
+{
+ struct bitmap_unplug_work *unplug_work =
+ container_of(work, struct bitmap_unplug_work, work);
+
+ md_bitmap_unplug(unplug_work->bitmap);
+ complete(unplug_work->done);
+}
+
+void md_bitmap_unplug_async(struct bitmap *bitmap)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+ struct bitmap_unplug_work unplug_work;
+
+ INIT_WORK_ONSTACK(&unplug_work.work, md_bitmap_unplug_fn);
+ unplug_work.bitmap = bitmap;
+ unplug_work.done = &done;
+
+ queue_work(md_bitmap_wq, &unplug_work.work);
+ wait_for_completion(&done);
+}
+EXPORT_SYMBOL(md_bitmap_unplug_async);
+
static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
* the in-memory bitmap from the on-disk bitmap -- also, sets up the
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h
index 3a4750952b3a7..8a3788c9bfef8 100644
--- a/drivers/md/md-bitmap.h
+++ b/drivers/md/md-bitmap.h
@@ -264,6 +264,7 @@ void md_bitmap_sync_with_cluster(struct mddev *mddev,
sector_t new_lo, sector_t new_hi);
void md_bitmap_unplug(struct bitmap *bitmap);
+void md_bitmap_unplug_async(struct bitmap *bitmap);
void md_bitmap_daemon_work(struct mddev *mddev);
int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0aec2954e1613..cf3733c90c47e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -83,6 +83,7 @@ static struct module *md_cluster_mod;
static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
static struct workqueue_struct *md_wq;
static struct workqueue_struct *md_misc_wq;
+struct workqueue_struct *md_bitmap_wq;
static int remove_and_add_spares(struct mddev *mddev,
struct md_rdev *this);
@@ -9637,6 +9638,11 @@ static int __init md_init(void)
if (!md_misc_wq)
goto err_misc_wq;
+ md_bitmap_wq = alloc_workqueue("md_bitmap", WQ_MEM_RECLAIM | WQ_UNBOUND,
+ 0);
+ if (!md_bitmap_wq)
+ goto err_bitmap_wq;
+
ret = __register_blkdev(MD_MAJOR, "md", md_probe);
if (ret < 0)
goto err_md;
@@ -9655,6 +9661,8 @@ static int __init md_init(void)
err_mdp:
unregister_blkdev(MD_MAJOR, "md");
err_md:
+ destroy_workqueue(md_bitmap_wq);
+err_bitmap_wq:
destroy_workqueue(md_misc_wq);
err_misc_wq:
destroy_workqueue(md_wq);
@@ -9951,6 +9959,7 @@ static __exit void md_exit(void)
spin_unlock(&all_mddevs_lock);
destroy_workqueue(md_misc_wq);
+ destroy_workqueue(md_bitmap_wq);
destroy_workqueue(md_wq);
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index a50122165fa16..bfd2306bc750d 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -852,6 +852,7 @@ struct mdu_array_info_s;
struct mdu_disk_info_s;
extern int mdp_major;
+extern struct workqueue_struct *md_bitmap_wq;
void md_autostart_arrays(int part);
int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info);
int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info);
--
2.30.2