xfs: type verification is expensive

Source kernel commit: ec08c14ba28ce073b3f63c8edbee0f3c38e1b6a1

From a concurrent rm -rf workload:

41.04%  [kernel]  [k] xfs_dir3_leaf_check_int
9.85%  [kernel]  [k] __xfs_dir3_data_check
5.60%  [kernel]  [k] xfs_verify_ino
5.32%  [kernel]  [k] xfs_agino_range
4.21%  [kernel]  [k] memcpy
3.06%  [kernel]  [k] xfs_errortag_test
2.57%  [kernel]  [k] xfs_dir_ino_validate
1.66%  [kernel]  [k] xfs_dir2_data_get_ftype
1.17%  [kernel]  [k] do_raw_spin_lock
1.11%  [kernel]  [k] xfs_verify_dir_ino
0.84%  [kernel]  [k] __raw_callee_save___pv_queued_spin_unlock
0.83%  [kernel]  [k] xfs_buf_find
0.64%  [kernel]  [k] xfs_log_commit_cil

THere's an awful lot of overhead in just range checking inode
numbers in that, but each inode number check is not a lot of code.
The total is a bit over 14.5% of the CPU time is spent validating
inode numbers.

The problem is that they deeply nested global scope functions so the
overhead here is all in function call marshalling.

text    data     bss     dec     hex filename
2077       0       0    2077     81d fs/xfs/libxfs/xfs_types.o.orig
2197       0       0    2197     895 fs/xfs/libxfs/xfs_types.o

There's a small increase in binary size by inlining all the local
nested calls in the verifier functions, but the same workload now
profiles as:

40.69%  [kernel]  [k] xfs_dir3_leaf_check_int
10.52%  [kernel]  [k] __xfs_dir3_data_check
6.68%  [kernel]  [k] xfs_verify_dir_ino
4.22%  [kernel]  [k] xfs_errortag_test
4.15%  [kernel]  [k] memcpy
3.53%  [kernel]  [k] xfs_dir_ino_validate
1.87%  [kernel]  [k] xfs_dir2_data_get_ftype
1.37%  [kernel]  [k] do_raw_spin_lock
0.98%  [kernel]  [k] xfs_buf_find
0.94%  [kernel]  [k] __raw_callee_save___pv_queued_spin_unlock
0.73%  [kernel]  [k] xfs_log_commit_cil

Now we only spend just over 10% of the time validing inode numbers
for the same workload. Hence a few "inline" keyworks is good enough
to reduce the validation overhead by 30%...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_types.c b/libxfs/xfs_types.c
index af9f6343499f44d4ce9c91cb819e787652dc9681..8e67c5bbc2a7d069afd40608f8c665f51678b69b 100644 (file)
--- a/libxfs/xfs_types.c
+++ b/libxfs/xfs_types.c
@@ -13,7 +13,7 @@
 #include "xfs_mount.h"
 
 /* Find the size of the AG, in blocks. */
-xfs_agblock_t
+inline xfs_agblock_t
 xfs_ag_block_count(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno)
@@ -29,7 +29,7 @@ xfs_ag_block_count(
  * Verify that an AG block number pointer neither points outside the AG
  * nor points at static metadata.
  */
-bool
+inline bool
 xfs_verify_agbno(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno,
@@ -49,7 +49,7 @@ xfs_verify_agbno(
  * Verify that an FS block number pointer neither points outside the
  * filesystem nor points at static AG metadata.
  */
-bool
+inline bool
 xfs_verify_fsbno(
        struct xfs_mount        *mp,
        xfs_fsblock_t           fsbno)
@@ -85,7 +85,7 @@ xfs_verify_fsbext(
 }
 
 /* Calculate the first and last possible inode number in an AG. */
-void
+inline void
 xfs_agino_range(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno,
@@ -116,7 +116,7 @@ xfs_agino_range(
  * Verify that an AG inode number pointer neither points outside the AG
  * nor points at static metadata.
  */
-bool
+inline bool
 xfs_verify_agino(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno,
@@ -146,7 +146,7 @@ xfs_verify_agino_or_null(
  * Verify that an FS inode number pointer neither points outside the
  * filesystem nor points at static AG metadata.
  */
-bool
+inline bool
 xfs_verify_ino(
        struct xfs_mount        *mp,
        xfs_ino_t               ino)
@@ -162,7 +162,7 @@ xfs_verify_ino(
 }
 
 /* Is this an internal inode number? */
-bool
+inline bool
 xfs_internal_inum(
        struct xfs_mount        *mp,
        xfs_ino_t               ino)
@@ -190,7 +190,7 @@ xfs_verify_dir_ino(
  * Verify that an realtime block number pointer doesn't point off the
  * end of the realtime device.
  */
-bool
+inline bool
 xfs_verify_rtbno(
        struct xfs_mount        *mp,
        xfs_rtblock_t           rtbno)
@@ -215,7 +215,7 @@ xfs_verify_rtext(
 }
 
 /* Calculate the range of valid icount values. */
-void
+inline void
 xfs_icount_range(
        struct xfs_mount        *mp,
        unsigned long long      *min,