swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Revision c76febef574fd86566bbdf1a73a547a439115c25 authored by Dave Chinner on 30 November 2010, 04:15:31 UTC, committed by Alex Elder on 01 December 2010, 13:40:20 UTC
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>
1 parent de25c18
Tip revision: 53d5fc89d66a778577295020dc57bb3ccec84354 authored by Linus Torvalds on 01 October 2021, 21:45:23 UTC
Merge tag 's390-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Merge tag 's390-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Tip revision: 53d5fc8
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 936 bytes |
.mailmap | -rw-r--r-- | 3.9 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 91.8 KB |
Kbuild | -rw-r--r-- | 2.4 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 178.4 KB |
Makefile | -rw-r--r-- | 50.9 KB |
README | -rw-r--r-- | 17.1 KB |
REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
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