| Message ID | 20240328082943.20251-3-heming.zhao@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | improve write IO performance when fragmentation is high | expand |
On 3/28/24 4:29 PM, Heming Zhao wrote: > After introducing gd->bg_contig_free_bits, the code path > 'ocfs2_cluster_group_search() => ocfs2_local_alloc_seen_free_bits()' > becomes death when all the gd->bg_contig_free_bits are set to the > correct value. This patch relocates ocfs2_local_alloc_seen_free_bits() > to a more appropriate location. (The new place being > ocfs2_block_group_set_bits().) > > In ocfs2_local_alloc_seen_free_bits(), the scope of the spin-lock has > been adjusted to reduce meaningless lock races. e.g: when userspace > creates & deletes 1 cluster_size files in parallel, acquiring the > spin-lock in ocfs2_local_alloc_seen_free_bits() is totally pointless and > impedes IO performance. > > Signed-off-by: Heming Zhao <heming.zhao@suse.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> > --- > v5: > put 'osb->local_alloc_state = OCFS2_LA_ENABLED' into the if block > > v4: first verion > --- > fs/ocfs2/localalloc.c | 11 ++++++----- > fs/ocfs2/suballoc.c | 9 ++------- > 2 files changed, 8 insertions(+), 12 deletions(-) > > diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c > index c803c10dd97e..b893ef56accd 100644 > --- a/fs/ocfs2/localalloc.c > +++ b/fs/ocfs2/localalloc.c > @@ -212,14 +212,15 @@ static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb) > void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb, > unsigned int num_clusters) > { > - spin_lock(&osb->osb_lock); > - if (osb->local_alloc_state == OCFS2_LA_DISABLED || > - osb->local_alloc_state == OCFS2_LA_THROTTLED) > - if (num_clusters >= osb->local_alloc_default_bits) { > + if (num_clusters >= osb->local_alloc_default_bits) { > + spin_lock(&osb->osb_lock); > + if (osb->local_alloc_state == OCFS2_LA_DISABLED || > + osb->local_alloc_state == OCFS2_LA_THROTTLED) { > cancel_delayed_work(&osb->la_enable_wq); > osb->local_alloc_state = OCFS2_LA_ENABLED; > } > - spin_unlock(&osb->osb_lock); > + spin_unlock(&osb->osb_lock); > + } > } > > void ocfs2_la_enable_worker(struct work_struct *work) > diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c > index 1a7b53fd468d..fc80cb3dbcd1 100644 > --- a/fs/ocfs2/suballoc.c > +++ b/fs/ocfs2/suballoc.c > @@ -1374,6 +1374,7 @@ int ocfs2_block_group_set_bits(handle_t *handle, > int journal_type = OCFS2_JOURNAL_ACCESS_WRITE; > unsigned int start = bit_off + num_bits; > u16 contig_bits; > + struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb); > > /* All callers get the descriptor via > * ocfs2_read_group_descriptor(). Any corruption is a code bug. */ > @@ -1423,6 +1424,7 @@ int ocfs2_block_group_set_bits(handle_t *handle, > if (contig_bits > max_contig_bits) > max_contig_bits = contig_bits; > bg->bg_contig_free_bits = cpu_to_le16(max_contig_bits); > + ocfs2_local_alloc_seen_free_bits(osb, max_contig_bits); > } else { > bg->bg_contig_free_bits = 0; > } > @@ -1589,13 +1591,6 @@ static int ocfs2_cluster_group_search(struct inode *inode, > * of bits. */ > if (min_bits <= res->sr_bits) > search = 0; /* success */ > - else if (res->sr_bits) { > - /* > - * Don't show bits which we'll be returning > - * for allocation to the local alloc bitmap. > - */ > - ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits); > - } > } > > return search;
diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c index c803c10dd97e..b893ef56accd 100644 --- a/fs/ocfs2/localalloc.c +++ b/fs/ocfs2/localalloc.c @@ -212,14 +212,15 @@ static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb) void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb, unsigned int num_clusters) { - spin_lock(&osb->osb_lock); - if (osb->local_alloc_state == OCFS2_LA_DISABLED || - osb->local_alloc_state == OCFS2_LA_THROTTLED) - if (num_clusters >= osb->local_alloc_default_bits) { + if (num_clusters >= osb->local_alloc_default_bits) { + spin_lock(&osb->osb_lock); + if (osb->local_alloc_state == OCFS2_LA_DISABLED || + osb->local_alloc_state == OCFS2_LA_THROTTLED) { cancel_delayed_work(&osb->la_enable_wq); osb->local_alloc_state = OCFS2_LA_ENABLED; } - spin_unlock(&osb->osb_lock); + spin_unlock(&osb->osb_lock); + } } void ocfs2_la_enable_worker(struct work_struct *work) diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 1a7b53fd468d..fc80cb3dbcd1 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1374,6 +1374,7 @@ int ocfs2_block_group_set_bits(handle_t *handle, int journal_type = OCFS2_JOURNAL_ACCESS_WRITE; unsigned int start = bit_off + num_bits; u16 contig_bits; + struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb); /* All callers get the descriptor via * ocfs2_read_group_descriptor(). Any corruption is a code bug. */ @@ -1423,6 +1424,7 @@ int ocfs2_block_group_set_bits(handle_t *handle, if (contig_bits > max_contig_bits) max_contig_bits = contig_bits; bg->bg_contig_free_bits = cpu_to_le16(max_contig_bits); + ocfs2_local_alloc_seen_free_bits(osb, max_contig_bits); } else { bg->bg_contig_free_bits = 0; } @@ -1589,13 +1591,6 @@ static int ocfs2_cluster_group_search(struct inode *inode, * of bits. */ if (min_bits <= res->sr_bits) search = 0; /* success */ - else if (res->sr_bits) { - /* - * Don't show bits which we'll be returning - * for allocation to the local alloc bitmap. - */ - ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits); - } } return search;
After introducing gd->bg_contig_free_bits, the code path 'ocfs2_cluster_group_search() => ocfs2_local_alloc_seen_free_bits()' becomes death when all the gd->bg_contig_free_bits are set to the correct value. This patch relocates ocfs2_local_alloc_seen_free_bits() to a more appropriate location. (The new place being ocfs2_block_group_set_bits().) In ocfs2_local_alloc_seen_free_bits(), the scope of the spin-lock has been adjusted to reduce meaningless lock races. e.g: when userspace creates & deletes 1 cluster_size files in parallel, acquiring the spin-lock in ocfs2_local_alloc_seen_free_bits() is totally pointless and impedes IO performance. Signed-off-by: Heming Zhao <heming.zhao@suse.com> --- v5: put 'osb->local_alloc_state = OCFS2_LA_ENABLED' into the if block v4: first verion --- fs/ocfs2/localalloc.c | 11 ++++++----- fs/ocfs2/suballoc.c | 9 ++------- 2 files changed, 8 insertions(+), 12 deletions(-)