From 97d3ac75e5e0ebf7ca38ae74cebd201c09b97ab2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 24 Apr 2011 19:06:16 +0000 Subject: xfs: exact busy extent tracking Update the extent tree in case we have to reuse a busy extent, so that it always is kept uptodate. This is done by replacing the busy list searches with a new xfs_alloc_busy_reuse helper, which updates the busy extent tree in case of a reuse. This allows us to allow reusing metadata extents unconditionally, and thus avoid log forces especially for allocation btree blocks. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_alloc.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/xfs/xfs_alloc.h') diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index d0b3bc72005b..de5e27c95170 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -145,6 +145,10 @@ xfs_alloc_busy_clear(struct xfs_mount *mp, struct xfs_busy_extent *busyp); int xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len); + +void +xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, + xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); #endif /* __KERNEL__ */ /* -- cgit v1.2.3 From 8a072a4d4c6a5b6ec32836c467d2996393c76c6f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 24 Apr 2011 19:06:17 +0000 Subject: xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy Instead of finding the per-ag and then taking and releasing the pagb_lock for every single busy extent completed sort the list of busy extents and only switch betweens AGs where nessecary. This becomes especially important with the online discard support which will hit this lock more often. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_alloc.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'fs/xfs/xfs_alloc.h') diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index de5e27c95170..240ad288f2f9 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -140,7 +140,7 @@ xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len); void -xfs_alloc_busy_clear(struct xfs_mount *mp, struct xfs_busy_extent *busyp); +xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list); int xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, @@ -149,6 +149,15 @@ xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, void xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); + +int +xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b); + +static inline void xfs_alloc_busy_sort(struct list_head *list) +{ + list_sort(NULL, list, xfs_busy_extent_ag_cmp); +} + #endif /* __KERNEL__ */ /* -- cgit v1.2.3 From e84661aa84e2e003738563f65155d4f12dc474e7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 20 May 2011 13:45:32 +0000 Subject: xfs: add online discard support Now that we have reliably tracking of deleted extents in a transaction we can easily implement "online" discard support which calls blkdev_issue_discard once a transaction commits. The actual discard is a two stage operation as we first have to mark the busy extent as not available for reuse before we can start the actual discard. Note that we don't bother supporting discard for the non-delaylog mode. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_alloc.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/xfs/xfs_alloc.h') diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index 240ad288f2f9..06aa8217452b 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -140,7 +140,8 @@ xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len); void -xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list); +xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, + bool do_discard); int xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, -- cgit v1.2.3 From 55a7bc5a30ff2d30d8a34fea2af9fc601b32e61a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 May 2011 18:55:15 +0000 Subject: xfs: do not discard alloc btree blocks Blocks for the allocation btree are allocated from and released to the AGFL, and thus frequently reused. Even worse we do not have an easy way to avoid using an AGFL block when it is discarded due to the simple FILO list of free blocks, and thus can frequently stall on blocks that are currently undergoing a discard. Add a flag to the busy extent tracking structure to skip the discard for allocation btree blocks. In normal operation these blocks are reused frequently enough that there is no need to discard them anyway, but if they spill over to the allocation btree as part of a balance we "leak" blocks that we would otherwise discard. We could fix this by adding another flag and keeping these block in the rbtree even after they aren't busy any more so that we could discard them when they migrate out of the AGFL. Given that this would cause significant overhead I don't think it's worthwile for now. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_alloc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_alloc.h') diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index 06aa8217452b..2f52b924be79 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -137,7 +137,7 @@ xfs_alloc_longest_free_extent(struct xfs_mount *mp, #ifdef __KERNEL__ void xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, - xfs_agblock_t bno, xfs_extlen_t len); + xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags); void xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, -- cgit v1.2.3