diff options
| author | David Daney <ddaney@caviumnetworks.com> | 2010-02-04 11:31:49 -0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-02-27 12:53:42 +0100 |
| commit | 500c2e1fdbcc2b273bd4c695a9b8ac8196f61614 (patch) | |
| tree | f24c80f609a739beed194fd5c66abf9bc48ce0d6 /arch/mips/Kconfig.debug | |
| parent | e275ed5ee94b358964a0dae1c8b49f0bff260b60 (diff) | |
MIPS: Optimize spinlocks.
The current locking mechanism uses a ll/sc sequence to release a
spinlock. This is slower than a wmb() followed by a store to unlock.
The branching forward to .subsection 2 on sc failure slows down the
contended case. So we get rid of that part too.
Since we are now working on naturally aligned u16 values, we can get
rid of a masking operation as the LHU already does the right thing.
The ANDI are reversed for better scheduling on multi-issue CPUs
On a 12 CPU 750MHz Octeon cn5750 this patch improves ipv4 UDP packet
forwarding rates from 3.58*10^6 PPS to 3.99*10^6 PPS, or about 11%.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/937/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/Kconfig.debug')
0 files changed, 0 insertions, 0 deletions