diff mbox series

[16/22] btrfs: make max async discard size tunable

Message ID c3e6fa9d3391104c22c3e474af16a86d439a7af7.1576195673.git.dennis@kernel.org (mailing list archive)
State New, archived
Headers show
Series btrfs: async discard support | expand

Commit Message

Dennis Zhou Dec. 14, 2019, 12:22 a.m. UTC 
Expose max_discard_size as a tunable via sysfs.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
---
 fs/btrfs/ctree.h            |  1 +
 fs/btrfs/discard.c          |  1 +
 fs/btrfs/free-space-cache.c | 19 ++++++++++++-------
 fs/btrfs/sysfs.c            | 31 +++++++++++++++++++++++++++++++
 4 files changed, 45 insertions(+), 7 deletions(-)

Comments

David Sterba Dec. 30, 2019, 6:05 p.m. UTC | #1 
On Fri, Dec 13, 2019 at 04:22:25PM -0800, Dennis Zhou wrote:
> Expose max_discard_size as a tunable via sysfs.
> 
> Signed-off-by: Dennis Zhou <dennis@kernel.org>
> ---
>  fs/btrfs/ctree.h            |  1 +
>  fs/btrfs/discard.c          |  1 +
>  fs/btrfs/free-space-cache.c | 19 ++++++++++++-------
>  fs/btrfs/sysfs.c            | 31 +++++++++++++++++++++++++++++++
>  4 files changed, 45 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 1b2dae5962de..bf93ddbc773f 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -470,6 +470,7 @@ struct btrfs_discard_ctl {
>  	u64 prev_discard;
>  	atomic_t discardable_extents;
>  	atomic64_t discardable_bytes;
> +	u64 max_discard_size;
>  	u32 delay;
>  	u32 iops_limit;
>  	u64 bps_limit;
> diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
> index 085f36808e7f..dd5143f0283f 100644
> --- a/fs/btrfs/discard.c
> +++ b/fs/btrfs/discard.c
> @@ -536,6 +536,7 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info)
>  	discard_ctl->prev_discard = 0;
>  	atomic_set(&discard_ctl->discardable_extents, 0);
>  	atomic64_set(&discard_ctl->discardable_bytes, 0);
> +	discard_ctl->max_discard_size = BTRFS_ASYNC_DISCARD_MAX_SIZE;

BTRFS_ASYNC_DISCARD_MAX_SIZE won't be the upper limit anymore but a
default so it should be named as such.
Dennis Zhou Jan. 2, 2020, 4:50 p.m. UTC | #2 
On Mon, Dec 30, 2019 at 07:05:03PM +0100, David Sterba wrote:
> On Fri, Dec 13, 2019 at 04:22:25PM -0800, Dennis Zhou wrote:
> > Expose max_discard_size as a tunable via sysfs.
> > 
> > Signed-off-by: Dennis Zhou <dennis@kernel.org>
> > ---
> >  fs/btrfs/ctree.h            |  1 +
> >  fs/btrfs/discard.c          |  1 +
> >  fs/btrfs/free-space-cache.c | 19 ++++++++++++-------
> >  fs/btrfs/sysfs.c            | 31 +++++++++++++++++++++++++++++++
> >  4 files changed, 45 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> > index 1b2dae5962de..bf93ddbc773f 100644
> > --- a/fs/btrfs/ctree.h
> > +++ b/fs/btrfs/ctree.h
> > @@ -470,6 +470,7 @@ struct btrfs_discard_ctl {
> >  	u64 prev_discard;
> >  	atomic_t discardable_extents;
> >  	atomic64_t discardable_bytes;
> > +	u64 max_discard_size;
> >  	u32 delay;
> >  	u32 iops_limit;
> >  	u64 bps_limit;
> > diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
> > index 085f36808e7f..dd5143f0283f 100644
> > --- a/fs/btrfs/discard.c
> > +++ b/fs/btrfs/discard.c
> > @@ -536,6 +536,7 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info)
> >  	discard_ctl->prev_discard = 0;
> >  	atomic_set(&discard_ctl->discardable_extents, 0);
> >  	atomic64_set(&discard_ctl->discardable_bytes, 0);
> > +	discard_ctl->max_discard_size = BTRFS_ASYNC_DISCARD_MAX_SIZE;
> 
> BTRFS_ASYNC_DISCARD_MAX_SIZE won't be the upper limit anymore but a
> default so it should be named as such.

Renamed to BTRFS_ASYNC_DISCARD_MAX_SIZE_DFL.
diff mbox series

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1b2dae5962de..bf93ddbc773f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -470,6 +470,7 @@  struct btrfs_discard_ctl {
 	u64 prev_discard;
 	atomic_t discardable_extents;
 	atomic64_t discardable_bytes;
+	u64 max_discard_size;
 	u32 delay;
 	u32 iops_limit;
 	u64 bps_limit;
diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index 085f36808e7f..dd5143f0283f 100644
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -536,6 +536,7 @@  void btrfs_discard_init(struct btrfs_fs_info *fs_info)
 	discard_ctl->prev_discard = 0;
 	atomic_set(&discard_ctl->discardable_extents, 0);
 	atomic64_set(&discard_ctl->discardable_bytes, 0);
+	discard_ctl->max_discard_size = BTRFS_ASYNC_DISCARD_MAX_SIZE;
 	discard_ctl->delay = BTRFS_DISCARD_MAX_DELAY;
 	discard_ctl->iops_limit = BTRFS_DISCARD_MAX_IOPS;
 	discard_ctl->bps_limit = 0;
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 0dbcea6c59f9..e5bb37627807 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -3431,6 +3431,8 @@  static int trim_no_bitmap(struct btrfs_block_group *block_group,
 			  u64 *total_trimmed, u64 start, u64 end, u64 minlen,
 			  bool async)
 {
+	struct btrfs_discard_ctl *discard_ctl =
+					&block_group->fs_info->discard_ctl;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct btrfs_free_space *entry;
 	struct rb_node *node;
@@ -3439,6 +3441,7 @@  static int trim_no_bitmap(struct btrfs_block_group *block_group,
 	u64 extent_bytes;
 	enum btrfs_trim_state extent_trim_state;
 	u64 bytes;
+	u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
 
 	while (start < end) {
 		struct btrfs_trim_range trim_entry;
@@ -3476,11 +3479,10 @@  static int trim_no_bitmap(struct btrfs_block_group *block_group,
 				goto next;
 			}
 			unlink_free_space(ctl, entry);
-			if (bytes > BTRFS_ASYNC_DISCARD_MAX_SIZE) {
-				bytes = extent_bytes =
-					BTRFS_ASYNC_DISCARD_MAX_SIZE;
-				entry->offset += BTRFS_ASYNC_DISCARD_MAX_SIZE;
-				entry->bytes -= BTRFS_ASYNC_DISCARD_MAX_SIZE;
+			if (max_discard_size && bytes > max_discard_size) {
+				bytes = extent_bytes = max_discard_size;
+				entry->offset += max_discard_size;
+				entry->bytes -= max_discard_size;
 				link_free_space(ctl, entry);
 			} else {
 				kmem_cache_free(btrfs_free_space_cachep, entry);
@@ -3589,12 +3591,15 @@  static int trim_bitmaps(struct btrfs_block_group *block_group,
 			u64 *total_trimmed, u64 start, u64 end, u64 minlen,
 			bool async)
 {
+	struct btrfs_discard_ctl *discard_ctl =
+					&block_group->fs_info->discard_ctl;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct btrfs_free_space *entry;
 	int ret = 0;
 	int ret2;
 	u64 bytes;
 	u64 offset = offset_to_bitmap(ctl, start);
+	u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
 
 	while (offset < end) {
 		bool next_bitmap = false;
@@ -3664,8 +3669,8 @@  static int trim_bitmaps(struct btrfs_block_group *block_group,
 			goto next;
 		}
 
-		if (async && bytes > BTRFS_ASYNC_DISCARD_MAX_SIZE)
-			bytes = BTRFS_ASYNC_DISCARD_MAX_SIZE;
+		if (async && max_discard_size && bytes > max_discard_size)
+			bytes = max_discard_size;
 
 		bitmap_clear_bits(ctl, entry, start, bytes);
 		if (entry->bytes == 0)
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 12f7a906a36f..e71e8bbc57d0 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -404,6 +404,36 @@  static ssize_t btrfs_discard_bps_limit_store(struct kobject *kobj,
 BTRFS_ATTR_RW(discard, bps_limit, btrfs_discard_bps_limit_show,
 	      btrfs_discard_bps_limit_store);
 
+static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
+						   struct kobj_attribute *a,
+						   char *buf)
+{
+	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+
+	return snprintf(buf, PAGE_SIZE, "%llu\n",
+			READ_ONCE(fs_info->discard_ctl.max_discard_size));
+}
+
+static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
+						    struct kobj_attribute *a,
+						    const char *buf, size_t len)
+{
+	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
+	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
+	u64 max_discard_size;
+	int ret;
+
+	ret = kstrtou64(buf, 10, &max_discard_size);
+	if (ret)
+		return -EINVAL;
+
+	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
+
+	return len;
+}
+BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
+	      btrfs_discard_max_discard_size_store);
+
 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
 					      struct kobj_attribute *a,
 					      char *buf)
@@ -429,6 +459,7 @@  BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
 static const struct attribute *discard_debug_attrs[] = {
 	BTRFS_ATTR_PTR(discard, iops_limit),
 	BTRFS_ATTR_PTR(discard, bps_limit),
+	BTRFS_ATTR_PTR(discard, max_discard_size),
 	BTRFS_ATTR_PTR(discard, discardable_extents),
 	BTRFS_ATTR_PTR(discard, discardable_bytes),
 	NULL,