linux/fs/xfs
Dave Chinner c76febef57 xfs: only run xfs_error_test if error injection is active
Recent tests writing lots of small files showed the flusher thread
being CPU bound and taking a long time to do allocations on a debug
kernel. perf showed this as the prime reason:

             samples  pcnt function                    DSO
             _______ _____ ___________________________ _________________

           224648.00 36.8% xfs_error_test              [kernel.kallsyms]
            86045.00 14.1% xfs_btree_check_sblock      [kernel.kallsyms]
            39778.00  6.5% prandom32                   [kernel.kallsyms]
            37436.00  6.1% xfs_btree_increment         [kernel.kallsyms]
            29278.00  4.8% xfs_btree_get_rec           [kernel.kallsyms]
            27717.00  4.5% random32                    [kernel.kallsyms]

Walking btree blocks during allocation checking them requires each
block (a cache hit, so no I/O) call xfs_error_test(), which then
does a random32() call as the first operation.  IOWs, ~50% of the
CPU is being consumed just testing whether we need to inject an
error, even though error injection is not active.

Kill this overhead when error injection is not active by adding a
global counter of active error traps and only calling into
xfs_error_test when fault injection is active.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-01 07:40:20 -06:00
..
linux-2.6 xfs: push stale, pinned buffers on trylock failures 2010-12-01 07:40:20 -06:00
quota xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
support xfs: drop dmapi hooks 2010-07-26 13:16:33 -05:00
Kconfig quota: Make QUOTACTL config be selected by its users 2010-10-05 12:16:37 +02:00
Makefile xfs: simplify log item descriptor tracking 2010-07-26 13:16:34 -05:00
xfs_acl.h xfs: constify xattr_handler 2010-05-21 18:31:19 -04:00
xfs_ag.h xfs: convert buffer cache hash to rbtree 2010-10-18 15:07:56 -05:00
xfs_alloc_btree.c xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_alloc_btree.h
xfs_alloc.c xfs: eliminate some newly-reported gcc warnings 2010-10-18 15:07:39 -05:00
xfs_alloc.h xfs: do not use emums for flags used in tracing 2010-07-26 13:16:43 -05:00
xfs_arch.h xfs: use generic Posix ACL code 2009-06-10 17:07:47 +02:00
xfs_attr_leaf.c xfs: remove unused delta tracking code in xfs_bmapi 2010-07-26 13:16:39 -05:00
xfs_attr_leaf.h
xfs_attr_sf.h xfs: convert attr to use unsigned names 2010-01-20 10:47:48 +11:00
xfs_attr.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_attr.h xfs: convert attr to use unsigned names 2010-01-20 10:47:48 +11:00
xfs_bit.c
xfs_bit.h
xfs_bmap_btree.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_bmap_btree.h xfs: make several more functions static 2010-01-15 15:31:38 -06:00
xfs_bmap.c xfs: delayed alloc blocks beyond EOF are valid after writeback 2010-12-01 07:40:20 -06:00
xfs_bmap.h xfs: fix failed write truncation handling. 2010-12-01 07:40:19 -06:00
xfs_btree_trace.c
xfs_btree_trace.h xfs: event tracing support 2009-12-14 23:08:16 -06:00
xfs_btree.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_btree.h xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_buf_item.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_buf_item.h xfs: give li_cb callbacks the correct prototype 2010-07-26 13:16:35 -05:00
xfs_da_btree.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_da_btree.h xfs: convert dirnameops to unsigned char names 2010-01-20 10:47:17 +11:00
xfs_dfrag.c xfs: delayed alloc blocks beyond EOF are valid after writeback 2010-12-01 07:40:20 -06:00
xfs_dfrag.h xfs: clean up inconsistent variable naming in xfs_swap_extent 2010-01-15 15:31:23 -06:00
xfs_dinode.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_dir2_block.c xfs: fix gcc 4.6 set but not read and unused statement warnings 2010-07-26 13:16:51 -05:00
xfs_dir2_block.h
xfs_dir2_data.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_data.h
xfs_dir2_leaf.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_dir2_leaf.h
xfs_dir2_node.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_node.h xfs: make several more functions static 2010-01-15 15:31:38 -06:00
xfs_dir2_sf.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_dir2_sf.h
xfs_dir2.c xfs: split xfs_itrace_entry 2010-07-26 13:16:44 -05:00
xfs_dir2.h xfs: make xfs_dir_cilookup_result use unsigned char 2010-01-20 10:47:25 +11:00
xfs_error.c xfs: only run xfs_error_test if error injection is active 2010-12-01 07:40:20 -06:00
xfs_error.h xfs: only run xfs_error_test if error injection is active 2010-12-01 07:40:20 -06:00
xfs_extfree_item.c xfs: fix the xfs_log_iovec i_addr type 2010-07-26 13:16:36 -05:00
xfs_extfree_item.h
xfs_filestream.c xfs: tell lockdep about parent iolock usage in filestreams 2010-11-10 12:00:48 -06:00
xfs_filestream.h xfs: clean up filestreams helpers 2010-07-26 13:16:51 -05:00
xfs_fs.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_fsops.c xfs: do not use xfs_mod_incore_sb for per-cpu counters 2010-10-18 15:07:59 -05:00
xfs_fsops.h xfs: dummy transactions should not dirty VFS state 2010-08-24 11:46:31 +10:00
xfs_ialloc_btree.c xfs: remove the ->kill_root btree operation 2010-10-18 15:07:38 -05:00
xfs_ialloc_btree.h
xfs_ialloc.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_ialloc.h xfs: rationalize xfs_inobt_lookup* 2009-09-01 12:45:39 -05:00
xfs_iget.c xfs: fix bogus m_maxagi check in xfs_iget 2010-10-18 15:08:01 -05:00
xfs_inode_item.c xfs: avoid moving stale inodes in the AIL 2010-12-01 07:40:20 -06:00
xfs_inode_item.h xfs: simplify inode to transaction joining 2010-07-26 13:16:36 -05:00
xfs_inode.c xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_inode.h new helper: ihold() 2010-10-25 21:26:11 -04:00
xfs_inum.h xfs: remove XFS_INO64_OFFSET 2009-08-31 14:46:22 -05:00
xfs_iomap.c xfs: small cleanups for xfs_iomap / __xfs_get_blocks 2010-07-26 13:16:42 -05:00
xfs_iomap.h xfs: do not use emums for flags used in tracing 2010-07-26 13:16:43 -05:00
xfs_itable.c xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_itable.h xfs: remove block number from inode lookup code 2010-06-24 11:35:17 +10:00
xfs_log_cil.c xfs: reduce the number of CIL lock round trips during commit 2010-10-18 15:07:42 -05:00
xfs_log_priv.h xfs: force background CIL push under sustained load 2010-09-29 07:51:03 -05:00
xfs_log_recover.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_log_recover.h xfs: Clean up XFS_BLI_* flag namespace 2010-05-24 10:33:39 -05:00
xfs_log.c Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs 2010-10-22 17:32:27 -07:00
xfs_log.h xfs: remove the unused XFS_LOG_SLEEP and XFS_LOG_NOSLEEP flags 2010-07-26 13:16:38 -05:00
xfs_mount.c xfs: fix per-ag reference counting in inode reclaim tree walking 2010-11-10 12:00:48 -06:00
xfs_mount.h xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs_mru_cache.c xfs: Kill filestreams cache flush 2010-01-15 15:34:22 -06:00
xfs_mru_cache.h xfs: Kill filestreams cache flush 2010-01-15 15:34:22 -06:00
xfs_quota.h xfs: fix a few compiler warnings with CONFIG_XFS_QUOTA=n 2010-11-10 12:00:48 -06:00
xfs_rename.c xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_rtalloc.c xfs: use unhashed buffers for size checks 2010-10-18 15:07:50 -05:00
xfs_rtalloc.h xfs: be more explicit if RT mount fails due to config 2010-05-28 14:58:24 -05:00
xfs_rw.c xfs: remove unneeded #include statements 2010-07-26 13:16:33 -05:00
xfs_rw.h xfs: only clear the suid bit once in xfs_write 2010-02-12 13:43:57 -06:00
xfs_sb.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_trans_ail.c xfs: drop dmapi hooks 2010-07-26 13:16:33 -05:00
xfs_trans_buf.c xfs: remove xfs_buf wrappers 2010-10-18 15:08:07 -05:00
xfs_trans_extfree.c xfs: simplify log item descriptor tracking 2010-07-26 13:16:34 -05:00
xfs_trans_inode.c xfs: don't use vfs writeback for pure metadata modifications 2010-10-18 15:07:45 -05:00
xfs_trans_priv.h xfs: unlock items before allowing the CIL to commit 2010-08-24 11:42:52 +10:00
xfs_trans_space.h
xfs_trans.c xfs: fix the xfs_trans_committed 2010-10-18 15:08:02 -05:00
xfs_trans.h xfs: remove unused t_callback field in struct xfs_trans 2010-10-18 15:08:01 -05:00
xfs_types.h xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_utils.c xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs_utils.h xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs_vnodeops.c xfs: Extend project quotas to support 32bit project ids 2010-10-18 15:08:08 -05:00
xfs_vnodeops.h xfs: remove xfs_cred.h 2010-10-18 15:08:06 -05:00
xfs.h xfs: event tracing support 2009-12-14 23:08:16 -06:00