linux/fs/xfs/support
David Chinner d234154125 [XFS] Use power-of-2 sized buffers to reduce overhead
Now that the ktrace_enter() code is using atomics, the non-power-of-2
buffer sizes - which require modulus operations to get the index - are
showing up as using substantial CPU in the profiles.

Force the buffer sizes to be rounded up to the nearest power of two and
use masking rather than modulus operations to convert the index counter to
the buffer index. This reduces ktrace_enter overhead to 8% of a CPU time,
and again almost halves the trace intensive test runtime.

SGI-PV: 977546
SGI-Modid: xfs-linux-melb:xfs-kern:30538a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:40:04 +10:00
..
debug.c [XFS] lose xfs_hex_dump in favor of print_hex_dump 2008-02-07 18:13:05 +11:00
debug.h [XFS] fix ASSERT and ASSERT_ALWAYS 2007-09-05 14:49:30 +10:00
ktrace.c [XFS] Use power-of-2 sized buffers to reduce overhead 2008-04-18 11:40:04 +10:00
ktrace.h [XFS] Use power-of-2 sized buffers to reduce overhead 2008-04-18 11:40:04 +10:00
uuid.c [XFS] add __init/__exit mark to specific init/cleanup functions 2008-02-07 18:25:19 +11:00
uuid.h