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authorDave Chinner <dchinner@redhat.com>2016-12-05 14:38:58 +1100
committerDave Chinner <david@fromorbit.com>2016-12-05 14:38:58 +1100
commit11ef38afe98cc7ad1a46ef24945232ec1760d5e2 (patch)
treeb198c9b46f06a7bcac329cd9d9a6a913ae3312ad /fs/xfs/libxfs/xfs_refcount_btree.c
parent1bb33a98702d8360947f18a44349df75ba555d5d (diff)
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xfs: make xfs btree stats less huge
Embedding a switch statement in every btree stats inc/add adds a lot of code overhead to the core btree infrastructure paths. Stats are supposed to be small and lightweight, but the btree stats have become big and bloated as we've added more btrees. It needs fixing because the reflink code will just add more overhead again. Convert the v2 btree stats to arrays instead of independent variables, and instead use the type to index the specific btree array via an enum. This allows us to use array based indexing to update the stats, rather than having to derefence variables specific to the btree type. If we then wrap the xfsstats structure in a union and place uint32_t array beside it, and calculate the correct btree stats array base array index when creating a btree cursor, we can easily access entries in the stats structure without having to switch names based on the btree type. We then replace with the switch statement with a simple set of stats wrapper macros, resulting in a significant simplification of the btree stats code, and: text data bss dec hex filename 48905 144 8 49057 bfa1 fs/xfs/libxfs/xfs_btree.o.old 36793 144 8 36945 9051 fs/xfs/libxfs/xfs_btree.o it reduces the core btree infrastructure code size by close to 25%! Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/libxfs/xfs_refcount_btree.c')
-rw-r--r--fs/xfs/libxfs/xfs_refcount_btree.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.c b/fs/xfs/libxfs/xfs_refcount_btree.c
index 453bb2757ec2..6fb2215f8ff7 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.c
+++ b/fs/xfs/libxfs/xfs_refcount_btree.c
@@ -354,6 +354,7 @@ xfs_refcountbt_init_cursor(
cur->bc_btnum = XFS_BTNUM_REFC;
cur->bc_blocklog = mp->m_sb.sb_blocklog;
cur->bc_ops = &xfs_refcountbt_ops;
+ cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_refcbt_2);
cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);