1. 27 Aug, 2013 3 commits
    • Ken Steele's avatar
      RAID: add tilegx SIMD implementation of raid6 · ae77cbc1
      Ken Steele authored
      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: default avatarKen Steele <ken@tilera.com>
      Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      ae77cbc1
    • NeilBrown's avatar
      md: fix safe_mode buglet. · 275c51c4
      NeilBrown authored
      Whe we set the safe_mode_timeout to a smaller value we trigger a timeout
      immediately - otherwise the small value might not be honoured.
      However if the previous timeout was 0 meaning "no timeout", we didn't.
      This would mean that no timeout happens until the next write completes,
      which could be a long time.
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      275c51c4
    • NeilBrown's avatar
      md: don't call md_allow_write in get_bitmap_file. · 60559da4
      NeilBrown authored
      There is no really need as GFP_NOIO is very likely sufficient,
      and failure is not catastrophic.
      
      Calling md_allow_write here will convert a read-auto array to
      read/write which could be confusing when you are just performing
      a read operation.
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      60559da4
  2. 26 Aug, 2013 1 commit
  3. 25 Aug, 2013 4 commits
  4. 24 Aug, 2013 8 commits
  5. 23 Aug, 2013 17 commits
  6. 22 Aug, 2013 7 commits