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* md/raid6 algorithms: xor_syndrome() for SSE2Markus Stockhausen2015-04-221-3/+227
| | | | | | | | | | | | | | The second and (last) optimized XOR syndrome calculation. This version supports right and left side optimization. All CPUs with architecture older than Haswell will benefit from it. It should be noted that SSE2 movntdq kills performance for memory areas that are read and written simultaneously in chunks smaller than cache line size. So use movdqa instead for P/Q writes in sse21 and sse22 XOR functions. Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid6 algorithms: xor_syndrome() for generic intMarkus Stockhausen2015-04-221-1/+39
| | | | | | | | | | Start the algorithms with the very basic one. It is left and right optimized. That means we can avoid all calculations for unneeded pages above the right stop offset. For pages below the left start offset we still need the syndrome multiplication but without reading data pages. Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid6 algorithms: improve test programMarkus Stockhausen2015-04-221-15/+36
| | | | | | | | | | | | | It is always helpful to have a test tool in place if we implement new data critical algorithms. So add some test routines to the raid6 checker that can prove if the new xor_syndrome() works as expected. Run through all permutations of start/stop pages per algorithm and simulate a xor_syndrome() assisted rmw run. After each rmw check if the recovery algorithm still confirms that the stripe is fine. Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid6 algorithms: delta syndrome functionsMarkus Stockhausen2015-04-229-8/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | v3: s-o-b comment, explanation of performance and descision for the start/stop implementation Implementing rmw functionality for RAID6 requires optimized syndrome calculation. Up to now we can only generate a complete syndrome. The target P/Q pages are always overwritten. With this patch we provide a framework for inplace P/Q modification. In the first place simply fill those functions with NULL values. xor_syndrome() has two additional parameters: start & stop. These will indicate the first and last page that are changing during a rmw run. That makes it possible to avoid several unneccessary loops and speed up calculation. The caller needs to implement the following logic to make the functions work. 1) xor_syndrome(disks, start, stop, ...): "Remove" all data of source blocks inside P/Q between (and including) start and end. 2) modify any block with start <= block <= stop 3) xor_syndrome(disks, start, stop, ...): "Reinsert" all data of source blocks into P/Q between (and including) start and end. Pages between start and stop that won't be changed should be filled with a pointer to the kernel zero page. The reasons for not taking NULL pages are: 1) Algorithms cross the whole source data line by line. Thus avoid additional branches. 2) Having a NULL page avoids calculating the XOR P parity but still need calulation steps for the Q parity. Depending on the algorithm unrolling that might be only a difference of 2 instructions per loop. The benchmark numbers of the gen_syndrome() functions are displayed in the kernel log. Do the same for the xor_syndrome() functions. This will help to analyze performance problems and give an rough estimate how well the algorithm works. The choice of the fastest algorithm will still depend on the gen_syndrome() performance. With the start/stop page implementation the speed can vary a lot in real life. E.g. a change of page 0 & page 15 on a stripe will be harder to compute than the case where page 0 & page 1 are XOR candidates. To be not to enthusiatic about the expected speeds we will run a worse case test that simulates a change on the upper half of the stripe. So we do: 1) calculation of P/Q for the upper pages 2) continuation of Q for the lower (empty) pages Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
* x86/raid6: correctly check for assembler capabilitiesJan Beulich2015-02-043-2/+8
| | | | | | | | | | Just like for AVX2 (which simply needs an #if -> #ifdef conversion), SSSE3 assembler support should be checked for before using it. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: Add log level to printksAnton Blanchard2014-10-141-6/+6
| | | | | Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md/3.12' of git://neil.brown.name/mdLinus Torvalds2013-09-104-1/+103
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
| * raid6/test: replace echo -e with printfMax Filippov2013-08-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | -e is a non-standard echo option, echo output is implementation-dependent when it is used. Replace echo -e with printf as suggested by POSIX echo manual. Cc: NeilBrown <neilb@suse.de> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * RAID: add tilegx SIMD implementation of raid6Ken Steele2013-08-274-0/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | lib/raid6: add ARM-NEON accelerated syndrome calculationArd Biesheuvel2013-07-086-1/+210
|/ | | | | | | | | | | | 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 <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Cc: hpa@linux.intel.com
* lib/raid6: build proper files on corresponding archYuanhan Liu2012-12-138-27/+28
| | | | | | | | | | | sse and avx2 stuff only exist on x86 arch, and we don't need to build altivec on x86. And we can do that at lib/raid6/Makefile. Proposed-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: Add AVX2 optimized gen_syndrome functionsYuanhan Liu2012-12-134-2/+272
| | | | | | | | | | Add AVX2 optimized gen_syndrom functions, which is simply based on sse2.c written by hpa. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: Add AVX2 optimized recovery functionsJim Kukunas2012-12-135-7/+341
| | | | | | | | | | | | | 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" <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: fix sparse warnings in recovery functionsJim Kukunas2012-05-282-6/+8
| | | | | | | | | | | | | | | | | Make the recovery functions static to fix the following sparse warnings: lib/raid6/recov.c:25:6: warning: symbol 'raid6_2data_recov_intx1' was not declared. Should it be static? lib/raid6/recov.c:69:6: warning: symbol 'raid6_datap_recov_intx1' was not declared. Should it be static? lib/raid6/recov_ssse3.c:22:6: warning: symbol 'raid6_2data_recov_ssse3' was not declared. Should it be static? lib/raid6/recov_ssse3.c:197:6: warning: symbol 'raid6_datap_recov_ssse3' was not declared. Should it be static? Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: cleanup gen_syndrome function selectionJim Kukunas2012-05-221-47/+57
| | | | | | | | | | | 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 <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: update test program for recovery functionsJim Kukunas2012-05-223-17/+32
| | | | | | | | Test each combination of recovery and syndrome generation functions. Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: Add SSSE3 optimized recovery functionsJim Kukunas2012-05-225-5/+409
| | | | | | | | | Add SSSE3 optimized recovery functions, as well as a system for selecting the most appropriate recovery functions to use. Originally-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* lib/raid6: fix test program buildJim Kukunas2012-05-221-1/+1
| | | | | | | | <linux/module.h> drags in headers which are not visible to userspace, thus breaking the build for the test program. Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Remove all #inclusions of asm/system.hDavid Howells2012-03-281-1/+0
| | | | | | | | | Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
* Disintegrate asm/system.h for PowerPCDavid Howells2012-03-281-0/+1
| | | | | | | | Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
* md: Add in export.h for files using EXPORT_SYMBOLPaul Gortmaker2011-10-312-0/+2
| | | | | | | | These files were getting the defines for EXPORT_SYMBOL because device.h was including module.h. But we are going to put an end to that. So add the proper export.h include now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* md: Add module.h to all files using it implicitlyPaul Gortmaker2011-10-311-0/+1
| | | | | | | | 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 <module.h> explicitly in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* lib/raid6: Fix filename emitted in generated codeDan McGee2011-10-201-1/+1
| | | | | | | | The files were renamed in commit cc4589ebf; fix the name in the file itself. Signed-off-by: Dan McGee <dpmcgee@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Move .gitignore from drivers/md to lib/raid6NeilBrown2010-08-301-0/+4
| | | | | | | Another missing bit of the raid6 -> /lib move. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: NeilBrown <neilb@suse.de>
* Further tidyup of raid6 naming in lib/raid6NeilBrown2010-08-126-11/+11
| | | | | | | Rename raid6/raid6x86.h to raid6/x86.h and modify some comments. Signed-off-by: NeilBrown <neilb@suse.de>
* Make lib/raid6/test build correctly.NeilBrown2010-08-121-1/+1
| | | | | | Some bit-rot needs to be cleaned out. Signed-off-by: NeilBrown <neilb@suse.de>
* Rename raid6 files now they're in a 'raid6' directory.David Woodhouse2010-08-1111-117/+111
| | | | | | Linus asks 'why "raid6" twice?'. No reason. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge branch 'async' of macbook:git/btrfs-unstableDavid Woodhouse2010-08-097-77/+56
| | | | | | Conflicts: drivers/md/Makefile lib/raid6/unroll.pl
* md: Factor out RAID6 algorithms into lib/David Woodhouse2009-10-2913-0/+1610
We'll want to use these in btrfs too. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
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