linux/lib/raid6/algos.c, branch v3.12.10

Merge tag 'md/3.12' of git://neil.brown.name/md

2013-09-10T20:03:41Z

Pull md update from Neil Brown: "Headline item is multithreading for RAID5 so that more IO/sec can be supported on fast (SSD) devices. Also TILE-Gx SIMD suppor for RAID6 calculations and an assortment of bug fixes" * tag 'md/3.12' of git://neil.brown.name/md: raid5: only wakeup necessary threads md/raid5: flush out all pending requests before proceeding with reshape. md/raid5: use seqcount to protect access to shape in make_request. raid5: sysfs entry to control worker thread number raid5: offload stripe handle to workqueue raid5: fix stripe release order raid5: make release_stripe lockless md: avoid deadlock when dirty buffers during md_stop. md: Don't test all of mddev->flags at once. md: Fix apparent cut-and-paste error in super_90_validate raid6/test: replace echo -e with printf RAID: add tilegx SIMD implementation of raid6 md: fix safe_mode buglet. md: don't call md_allow_write in get_bitmap_file.

RAID: add tilegx SIMD implementation of raid6

2013-08-27T06:05:50Z

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 Signed-off-by: Chris Metcalf Signed-off-by: NeilBrown

lib/raid6: add ARM-NEON accelerated syndrome calculation

2013-07-08T21:09:18Z

Rebased/reworked a patch contributed by Rob Herring that uses NEON intrinsics to perform the RAID-6 syndrome calculations. It uses the existing unroll.awk code to generate several unrolled versions of which the best performing one is selected at boot time. Signed-off-by: Ard Biesheuvel Acked-by: Nicolas Pitre Cc: hpa@linux.intel.com

lib/raid6: Add AVX2 optimized gen_syndrome functions

2012-12-13T08:51:03Z

Add AVX2 optimized gen_syndrom functions, which is simply based on sse2.c written by hpa. Signed-off-by: Yuanhan Liu Reviewed-by: H. Peter Anvin Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown

lib/raid6: Add AVX2 optimized recovery functions

2012-12-13T05:42:01Z

Optimize RAID6 recovery functions to take advantage of the 256-bit YMM integer instructions introduced in AVX2. The patch was tested and benchmarked before submission. However hardware is not yet released so benchmark numbers cannot be reported. Acked-by: "H. Peter Anvin" Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown

lib/raid6: cleanup gen_syndrome function selection

2012-05-22T03:54:24Z

Reorders functions in raid6_algos as well as the preference check to reduce the number of functions tested on initialization. Also, creates symmetry between choosing the gen_syndrome functions and choosing the recovery functions. Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown

lib/raid6: Add SSSE3 optimized recovery functions

2012-05-22T03:54:18Z

Add SSSE3 optimized recovery functions, as well as a system for selecting the most appropriate recovery functions to use. Originally-by: H. Peter Anvin Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown

lib/raid6: fix test program build

2012-05-22T03:54:16Z

drags in headers which are not visible to userspace, thus breaking the build for the test program. Signed-off-by: Jim Kukunas Signed-off-by: NeilBrown

md: Add module.h to all files using it implicitly

2011-10-31T23:31:18Z

A pending cleanup will mean that module.h won't be implicitly everywhere anymore. Make sure the modular drivers in md dir are actually calling out for explicitly in advance. Signed-off-by: Paul Gortmaker

Further tidyup of raid6 naming in lib/raid6

2010-08-11T20:44:54Z

Rename raid6/raid6x86.h to raid6/x86.h and modify some comments. Signed-off-by: NeilBrown