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authorKen Steele <ken@tilera.com>2013-08-07 20:39:56 +0400
committerNeilBrown <neilb@suse.de>2013-08-27 10:05:50 +0400
commitae77cbc1e7b90473a2b0963bce0e1eb163873214 (patch)
tree0d412c9c4932c59c8b495aa6214f98404849af60 /include/linux/raid
parent275c51c4e34ed776d40a99dd97c1deee50303b07 (diff)
downloadlinux-ae77cbc1e7b90473a2b0963bce0e1eb163873214.tar.xz
RAID: add tilegx SIMD implementation of raid6
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@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'include/linux/raid')
-rw-r--r--include/linux/raid/pq.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h
index 8dfaa2ce2e95..6d5df8adb53a 100644
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -101,6 +101,7 @@ extern const struct raid6_calls raid6_altivec8;
extern const struct raid6_calls raid6_avx2x1;
extern const struct raid6_calls raid6_avx2x2;
extern const struct raid6_calls raid6_avx2x4;
+extern const struct raid6_calls raid6_tilegx8;
struct raid6_recov_calls {
void (*data2)(int, size_t, int, int, void **);