| Message ID | 2fff5aa06edf1387677bdb1329359295c6d38506.1676494550.git.boris@bur.io (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: fix size class loading logic | expand |
On Wed, Feb 15, 2023 at 12:59:49PM -0800, Boris Burkov wrote: > Make it possible to see the distribution of size classes for block > groups. Helpful for testing and debugging the allocator w.r.t. to size > classes. > > The new stats can be found at the path: > /sys/fs/btrfs/<uid>/allocation/<bg-type>/size_class > but they will only be non-zero for bg-type = data. > > Signed-off-by: Boris Burkov <boris@bur.io> > --- > fs/btrfs/sysfs.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 44 insertions(+) > > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index 8c5efa5813b3..4926cab2f507 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -9,6 +9,7 @@ > #include <linux/spinlock.h> > #include <linux/completion.h> > #include <linux/bug.h> > +#include <linux/list.h> > #include <crypto/hash.h> > #include "messages.h" > #include "ctree.h" > @@ -778,6 +779,47 @@ static ssize_t btrfs_chunk_size_store(struct kobject *kobj, > return len; > } > > +static ssize_t btrfs_size_classes_show(struct kobject *kobj, > + struct kobj_attribute *a, char *buf) > +{ > + struct btrfs_space_info *sinfo = to_space_info(kobj); > + struct btrfs_block_group *bg; > + u32 none = 0; > + u32 small = 0; > + u32 medium = 0; > + u32 large = 0; > + > + down_read(&sinfo->groups_sem); > + for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) { The lock in raid_bytes_show would be here, so with down_read(&sinfo->groups_sem); > + list_for_each_entry(bg, &sinfo->block_groups[i], list) { > + if (!btrfs_block_group_should_use_size_class(bg)) > + continue; > + switch (bg->size_class) { > + case BTRFS_BG_SZ_NONE: > + none++; > + break; > + case BTRFS_BG_SZ_SMALL: > + small++; > + break; > + case BTRFS_BG_SZ_MEDIUM: > + medium++; > + break; > + case BTRFS_BG_SZ_LARGE: > + large++; > + break; > + } > + } and up_read(&sinfo->groups_sem); the conditional check could be avoided completely > + if (rwsem_is_contended(&sinfo->groups_sem)) { > + up_read(&sinfo->groups_sem); > + cond_resched(); > + down_read(&sinfo->groups_sem); > + } > + } > + up_read(&sinfo->groups_sem); > + return sysfs_emit(buf, "none %u\nsmall %u\nmedium %u\nlarge %u\n", > + none, small, medium, large); > +}
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 8c5efa5813b3..4926cab2f507 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -9,6 +9,7 @@ #include <linux/spinlock.h> #include <linux/completion.h> #include <linux/bug.h> +#include <linux/list.h> #include <crypto/hash.h> #include "messages.h" #include "ctree.h" @@ -778,6 +779,47 @@ static ssize_t btrfs_chunk_size_store(struct kobject *kobj, return len; } +static ssize_t btrfs_size_classes_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_space_info *sinfo = to_space_info(kobj); + struct btrfs_block_group *bg; + u32 none = 0; + u32 small = 0; + u32 medium = 0; + u32 large = 0; + + down_read(&sinfo->groups_sem); + for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) { + list_for_each_entry(bg, &sinfo->block_groups[i], list) { + if (!btrfs_block_group_should_use_size_class(bg)) + continue; + switch (bg->size_class) { + case BTRFS_BG_SZ_NONE: + none++; + break; + case BTRFS_BG_SZ_SMALL: + small++; + break; + case BTRFS_BG_SZ_MEDIUM: + medium++; + break; + case BTRFS_BG_SZ_LARGE: + large++; + break; + } + } + if (rwsem_is_contended(&sinfo->groups_sem)) { + up_read(&sinfo->groups_sem); + cond_resched(); + down_read(&sinfo->groups_sem); + } + } + up_read(&sinfo->groups_sem); + return sysfs_emit(buf, "none %u\nsmall %u\nmedium %u\nlarge %u\n", + none, small, medium, large); +} + #ifdef CONFIG_BTRFS_DEBUG /* * Request chunk allocation with current chunk size. @@ -835,6 +877,7 @@ SPACE_INFO_ATTR(bytes_zone_unusable); SPACE_INFO_ATTR(disk_used); SPACE_INFO_ATTR(disk_total); BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store); +BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show); static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj, struct kobj_attribute *a, @@ -887,6 +930,7 @@ static struct attribute *space_info_attrs[] = { BTRFS_ATTR_PTR(space_info, disk_total), BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold), BTRFS_ATTR_PTR(space_info, chunk_size), + BTRFS_ATTR_PTR(space_info, size_classes), #ifdef CONFIG_BTRFS_DEBUG BTRFS_ATTR_PTR(space_info, force_chunk_alloc), #endif
Make it possible to see the distribution of size classes for block groups. Helpful for testing and debugging the allocator w.r.t. to size classes. The new stats can be found at the path: /sys/fs/btrfs/<uid>/allocation/<bg-type>/size_class but they will only be non-zero for bg-type = data. Signed-off-by: Boris Burkov <boris@bur.io> --- fs/btrfs/sysfs.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)