On Wed, Aug 9, 2017 at 11:26 PM, Michael Ellerman <m...@ellerman.id.au> wrote:
> Matt Brown <matthew.brown....@gmail.com> writes:
>> This patch uses the vpermxor instruction to optimise the raid6 Q syndrome.
>> This instruction was made available with POWER8, ISA version 2.07.
>> It allows for both vperm and vxor instructions to be done in a single
>> instruction. This has been tested for correctness on a ppc64le vm with a
>> basic RAID6 setup containing 5 drives.
>> The performance benchmarks are from the raid6test in the /lib/raid6/test
>> directory. These results are from an IBM Firestone machine with ppc64le
>> architecture. The benchmark results show a 35% speed increase over the best
>> existing algorithm for powerpc (altivec). The raid6test has also been run
>> on a big-endian ppc64 vm to ensure it also works for big-endian
>> Performance benchmarks:
>> raid6: altivecx4 gen() 18773 MB/s
>> raid6: altivecx8 gen() 19438 MB/s
>> raid6: vpermxor4 gen() 25112 MB/s
>> raid6: vpermxor8 gen() 26279 MB/s
>> Signed-off-by: Matt Brown <matthew.brown....@gmail.com>
>> Reviewed-by: Daniel Axtens <d...@axtens.net>
>> - added vpermxor files to .gitignore
>> - fixup whitespace
>> - added vpermxor objs to test/Makefile
>> - moved altivec.uc fix into other patch in series
>> include/linux/raid/pq.h | 4 ++
>> lib/raid6/.gitignore | 1 +
>> lib/raid6/Makefile | 27 ++++++++++++-
>> lib/raid6/algos.c | 4 ++
>> lib/raid6/test/Makefile | 17 +++++++-
>> lib/raid6/vpermxor.uc | 104
>> 6 files changed, 154 insertions(+), 3 deletions(-)
>> create mode 100644 lib/raid6/vpermxor.uc
> This version at least is not Cc'ed to any of the folks that
> get_maintainers.pl identifies for these files:
> $ ./scripts/get_maintainer.pl -f lib/raid6
> This seems like mostly a list of random folks who've touched this code,
> but maybe some of them would have comments?
Ah my bad. I've CC'ed them into this email chain.
Apologies for not including you guys in the original email.
Here is a link to the patchworks patch: