On Wed, 7 Aug 2013 12:39:56 -0400 Ken Steele <ken@xxxxxxxxxx> wrote: > This change adds TILE-Gx SIMD instructions to the software raid > (md), modeling the Altivec implementation. This is only for Syndrome > generation; there is more that could be done to improve recovery, > as in the recent Intel SSE3 recovery implementation. > > The code unrolls 8 times; this turns out to be the best on tilegx > hardware among the set 1, 2, 4, 8 or 16. The code reads one > cache-line of data from each disk, stores P and Q then goes to the > next cache-line. > > The test code in sys/linux/lib/raid6/test reports 2008 MB/s data > read rate for syndrome generation using 18 disks (16 data and 2 > parity). It was 1512 MB/s before this SIMD optimizations. This is > running on 1 core with all the data in cache. > > This is based on the paper The Mathematics of RAID-6. > (http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf). > > Signed-off-by: Ken Steele <ken@xxxxxxxxxx> > Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx> Thanks. Looks credible and you've obviously tested it so I've added it to my queue for the next merge window. One tiny little change I made: > clean: > rm -f *.o *.a mktables mktables.c *.uc int*.c altivec*.c tables.c raid6test > + rm tilegx*.c I made that "rm -f" for consistency. Thanks, NeilBrown
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