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2020-01-13md/raid6: fix algorithm choice under larger PAGE_SIZEZhengyuan Liu
There are several algorithms available for raid6 to generate xor and syndrome parity, including basic int1, int2 ... int32 and SIMD optimized implementation like sse and neon. To test and choose the best algorithms at the initial stage, we need provide enough disk data to feed the algorithms. However, the disk number we provided depends on page size and gfmul table, seeing bellow: const int disks = (65536/PAGE_SIZE) + 2; So when come to 64K PAGE_SIZE, there is only one data disk plus 2 parity disk, as a result the chosed algorithm is not reliable. For example, on my arm64 machine with 64K page enabled, it will choose intx32 as the best one, although the NEON implementation is better. This patch tries to fix the problem by defining a constant raid6 disk number to supporting arbitrary page size. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid6/test: fix a compilation warningZhengyuan Liu
The compilation warning is redefination showed as following: In file included from tables.c:2: ../../../include/linux/export.h:180: warning: "EXPORT_SYMBOL" redefined #define EXPORT_SYMBOL(sym) __EXPORT_SYMBOL(sym, "") In file included from tables.c:1: ../../../include/linux/raid/pq.h:61: note: this is the location of the previous definition #define EXPORT_SYMBOL(sym) Fixes: 69a94abb82ee ("export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols") Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid6/test: fix a compilation errorZhengyuan Liu
The compilation error is redeclaration showed as following: In file included from ../../../include/linux/limits.h:6, from /usr/include/x86_64-linux-gnu/bits/local_lim.h:38, from /usr/include/x86_64-linux-gnu/bits/posix1_lim.h:161, from /usr/include/limits.h:183, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/limits.h:194, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/syslimits.h:7, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/limits.h:34, from ../../../include/linux/raid/pq.h:30, from algos.c:14: ../../../include/linux/types.h:114:15: error: conflicting types for ‘int64_t’ typedef s64 int64_t; ^~~~~~~ In file included from /usr/include/stdint.h:34, from /usr/lib/gcc/x86_64-linux-gnu/8/include/stdint.h:9, from /usr/include/inttypes.h:27, from ../../../include/linux/raid/pq.h:29, from algos.c:14: /usr/include/x86_64-linux-gnu/bits/stdint-intn.h:27:19: note: previous \ declaration of ‘int64_t’ was here typedef __int64_t int64_t; Fixes: 54d50897d544 ("linux/kernel.h: split *_MAX and *_MIN macros into <linux/limits.h>") Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 48Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation inc 53 temple place ste 330 boston ma 02111 1307 usa either version 2 of the license or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 13 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170858.645641371@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version you should have received a copy of the gnu general public license for example usr src linux copying if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 20 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170858.552543146@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20lib/raid6: add option to skip algo benchmarkingDaniel Verkamp
This is helpful for systems where fast startup time is important. It is especially nice to avoid benchmarking RAID functions that are never used (for example, BTRFS selects RAID6_PQ even if the parity RAID mode is not in use). This saves 250+ milliseconds of boot time on modern x86 and ARM systems with a dozen or more available implementations. The new option is defaulted to 'y' to match the previous behavior of always benchmarking on init. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-12-20lib/raid6: avoid __attribute_const__ redefinitionDaniel Verkamp
This is defined in glibc's sys/cdefs.h on my system with the same definition as the raid6test fallback definition. Add a #ifndef check to avoid a compiler warning about redefining it. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-12-20lib/raid6: add missing include for raid6testDaniel Verkamp
Add #include <sys/time.h> for gettimeofday() to fix the compiler warning about an implicitly defined functions. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-04-07Merge tag 'powerpc-4.17-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Support for 4PB user address space on 64-bit, opt-in via mmap(). - Removal of POWER4 support, which was accidentally broken in 2016 and no one noticed, and blocked use of some modern instructions. - Workarounds so that the hypervisor can enable Transactional Memory on Power9. - A series to disable the DAWR (Data Address Watchpoint Register) on Power9. - More information displayed in the meltdown/spectre_v1/v2 sysfs files. - A vpermxor (Power8 Altivec) implementation for the raid6 Q Syndrome. - A big series to make the allocation of our pacas (per cpu area), kernel page tables, and per-cpu stacks NUMA aware when using the Radix MMU on Power9. And as usual many fixes, reworks and cleanups. Thanks to: Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Aneesh Kumar K.V, Anshuman Khandual, Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe Lombard, Cyril Bur, Daniel Axtens, Dave Young, Finn Thain, Frederic Barrat, Gustavo Romero, Horia Geantă, Jonathan Neuschäfer, Kees Cook, Larry Finger, Laurent Dufour, Laurent Vivier, Logan Gunthorpe, Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus Elfring, Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de Oliveira, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher Boessenkool, Simon Guo, Simon Horman, Stewart Smith, Sukadev Bhattiprolu, Suraj Jitindar Singh, Thiago Jung Bauermann, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wei Yongjun" * tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (207 commits) powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep powerpc/64s: Fix POWER9 DD2.2 and above in cputable features powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit powerpc/64s: Fix dt_cpu_ftrs to have restore_cpu clear unwanted LPCR bits Revert "powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead" powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo} powerpc: io.h: move iomap.h include so that it can use readq/writeq defs cxl: Fix possible deadlock when processing page faults from cxllib powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it powerpc/mm/radix: Update command line parsing for disable_radix powerpc/mm/radix: Parse disable_radix commandline correctly. powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix powerpc/mm/keys: Update documentation and remove unnecessary check powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead powerpc/64s/idle: Consolidate power9_offline_stop()/power9_idle_stop() powerpc/powernv: Always stop secondaries before reboot/shutdown powerpc: hard disable irqs in smp_send_stop loop powerpc: use NMI IPI for smp_send_stop powerpc/powernv: Fix SMT4 forcing idle code ...
2018-03-26raid: remove tile specific raid6 implementationArnd Bergmann
The Tile architecture is getting removed, so we no longer need this either. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-20lib/raid6/altivec: Add vpermxor implementation for raid6 Q syndromeMatt Brown
This patch uses the vpermxor instruction to optimise the raid6 Q syndrome. This instruction was made available with POWER8, ISA version 2.07. It allows for both vperm and vxor instructions to be done in a single instruction. This has been tested for correctness on a ppc64le vm with a basic RAID6 setup containing 5 drives. The performance benchmarks are from the raid6test in the /lib/raid6/test directory. These results are from an IBM Firestone machine with ppc64le architecture. The benchmark results show a 35% speed increase over the best existing algorithm for powerpc (altivec). The raid6test has also been run on a big-endian ppc64 vm to ensure it also works for big-endian architectures. Performance benchmarks: raid6: altivecx4 gen() 18773 MB/s raid6: altivecx8 gen() 19438 MB/s raid6: vpermxor4 gen() 25112 MB/s raid6: vpermxor8 gen() 26279 MB/s Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> [mpe: Add VPERMXOR macro so we can build with old binutils] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-09md/raid6: implement recovery using ARM NEON intrinsicsArd Biesheuvel
Provide a NEON accelerated implementation of the recovery algorithm, which supersedes the default byte-by-byte one. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-05-16lib/raid6: Add log-of-2 table for RAID6 HW requiring disk positionAnup Patel
The raid6_gfexp table represents {2}^n values for 0 <= n < 256. The Linux async_tx framework pass values from raid6_gfexp as coefficients for each source to prep_dma_pq() callback of DMA channel with PQ capability. This creates problem for RAID6 offload engines (such as Broadcom SBA) which take disk position (i.e. log of {2}) instead of multiplicative cofficients from raid6_gfexp table. This patch adds raid6_gflog table having log-of-2 value for any given x such that 0 <= x < 256. For any given disk coefficient x, the corresponding disk position is given by raid6_gflog[x]. The RAID6 offload engine driver can use this newly added raid6_gflog table to get disk position from multiplicative coefficient. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Shaohua Li <shli@fb.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-10-07Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/mdLinus Torvalds
Pull MD updates from Shaohua Li: "This update includes: - new AVX512 instruction based raid6 gen/recovery algorithm - a couple of md-cluster related bug fixes - fix a potential deadlock - set nonrotational bit for raid array with SSD - set correct max_hw_sectors for raid5/6, which hopefuly can improve performance a little bit - other minor fixes" * tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: md: set rotational bit raid6/test/test.c: bug fix: Specify aligned(alignment) attributes to the char arrays raid5: handle register_shrinker failure raid5: fix to detect failure of register_shrinker md: fix a potential deadlock md/bitmap: fix wrong cleanup raid5: allow arbitrary max_hw_sectors lib/raid6: Add AVX512 optimized xor_syndrome functions lib/raid6/test/Makefile: Add avx512 gen_syndrome and recovery functions lib/raid6: Add AVX512 optimized recovery functions lib/raid6: Add AVX512 optimized gen_syndrome functions md-cluster: make resync lock also could be interruptted md-cluster: introduce dlm_lock_sync_interruptible to fix tasks hang md-cluster: convert the completion to wait queue md-cluster: protect md_find_rdev_nr_rcu with rcu lock md-cluster: clean related infos of cluster md: changes for MD_STILL_CLOSED flag md-cluster: remove some unnecessary dlm_unlock_sync md-cluster: use FORCEUNLOCK in lockres_free md-cluster: call md_kick_rdev_from_array once ack failed
2016-09-21lib/raid6: Add AVX512 optimized recovery functionsGayatri Kammela
Optimize RAID6 recovery functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized recovery functions, which is simply based on recov_avx2.c written by Jim Kukunas This patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21lib/raid6: Add AVX512 optimized gen_syndrome functionsGayatri Kammela
Optimize RAID6 gen_syndrom functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized gen_syndrom functions, which is simply based on avx2.c written by Yuanhan Liu and sse2.c written by hpa. The patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-01RAID/s390: provide raid6 recovery optimizationMartin Schwidefsky
The XC instruction can be used to improve the speed of the raid6 recovery. The loops now operate on blocks of 256 bytes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29RAID/s390: add SIMD implementation for raid6 gen/xorMartin Schwidefsky
Using vector registers is slightly faster: raid6: vx128x8 gen() 19705 MB/s raid6: vx128x8 xor() 11886 MB/s raid6: using algorithm vx128x8 gen() 19705 MB/s raid6: .... xor() 11886 MB/s, rmw enabled vs the software algorithms: raid6: int64x1 gen() 3018 MB/s raid6: int64x1 xor() 1429 MB/s raid6: int64x2 gen() 4661 MB/s raid6: int64x2 xor() 3143 MB/s raid6: int64x4 gen() 5392 MB/s raid6: int64x4 xor() 3509 MB/s raid6: int64x8 gen() 4441 MB/s raid6: int64x8 xor() 3207 MB/s raid6: using algorithm int64x4 gen() 5392 MB/s raid6: .... xor() 3509 MB/s, rmw enabled Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-21raid6/algos.c : bug fix : Add the missing definitions to the pq.h fileGayatri Kammela
Adding these pr_info and pr_err definitions so as to allow code to be compiled successfully for testing in userspace, since the printk has been replaced by pr_info and pr_err in algos.c Absence of these definitions result in the compilation errors such as ' undefined reference to `pr_info' ' ' undefined reference to `pr_err' ' Cc: NeilBrown <neilb@suse.com> Cc: Anton Blanchard <anton@samba.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2015-04-22md/raid6 algorithms: delta syndrome functionsMarkus Stockhausen
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>
2013-09-10Merge tag 'md/3.12' of git://neil.brown.name/mdLinus Torvalds
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.
2013-08-27RAID: add tilegx SIMD implementation of raid6Ken Steele
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>
2013-07-08lib/raid6: add ARM-NEON accelerated syndrome calculationArd Biesheuvel
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
2013-01-02UAPI: Remove empty Kbuild filesDavid Howells
Empty files can get deleted by the patch program, so remove empty Kbuild files and their links from the parent Kbuilds. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-13lib/raid6: Add AVX2 optimized gen_syndrome functionsYuanhan Liu
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>
2012-12-13lib/raid6: Add AVX2 optimized recovery functionsJim Kukunas
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>
2012-10-09UAPI: (Scripted) Disintegrate include/linux/raidDavid Howells
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-05-22lib/raid6: Add SSSE3 optimized recovery functionsJim Kukunas
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>
2012-05-21md: add possibility to change data-offset for devices.NeilBrown
When reshaping we can avoid costly intermediate backup by changing the 'start' address of the array on the device (if there is enough room). So as a first step, allow such a change to be requested through sysfs, and recorded in v1.x metadata. (As we didn't previous check that all 'pad' fields were zero, we need a new FEATURE flag for this. A (belatedly) check that all remaining 'pad' fields are zero to avoid a repeat of this) The new data offset must be requested separately for each device. This allows each to have a different change in the data offset. This is not likely to be used often but as data_offset can be set per-device, new_data_offset should be too. This patch also removes the 'acknowledged' arg to rdev_set_badblocks as it is never used and never will be. At the same time we add a new arg ('in_new') which is currently always zero but will be used more soon. When a reshape finishes we will need to update the data_offset and rdev->sectors. So provide an exported function to do that. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21md: allow a reshape operation to be reversed.NeilBrown
Currently a reshape operation always progresses from the start of the array to the end unless the number of devices is being reduced, in which case it progressed in the opposite direction. To reverse a partial reshape which changes the number of devices you can stop the array and re-assemble with the raid-disks numbers reversed and it will undo. However for a reshape that does not change the number of devices it is not possible to reverse the reshape in the middle - you have to wait until it completes. So add a 'reshape_direction' attribute with is either 'forwards' or 'backwards' and can be explicitly set when delta_disks is zero. This will become more important when we allow the data_offset to change in a reshape. Then the explicit statement of what direction is being used will be more useful. This can be enabled in raid5 trivially as it already supports reverse reshape and just needs to use a different trigger to request it. Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-13md: Use existed macros instead of numbersmajianpeng
Signed-off-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23md: create externally visible flags for supporting hot-replace.NeilBrown
hot-replace is a feature being added to md which will allow a device to be replaced without removing it from the array first. With hot-replace a spare can be activated and recovery can start while the original device is still in place, thus allowing a transition from an unreliable device to a reliable device without leaving the array degraded during the transition. It can also be use when the original device is still reliable but it not wanted for some reason. This will eventually be supported in RAID4/5/6 and RAID10. This patch adds a super-block flag to distinguish the replacement device. If an old kernel sees this flag it will reject the device. It also adds two per-device flags which are viewable and settable via sysfs. "want_replacement" can be set to request that a device be replaced. "replacement" is set to show that this device is replacing another device. The "rd%d" links in /sys/block/mdXx/md only apply to the original device, not the replacement. We currently don't make links for the replacement - there doesn't seem to be a need. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23md: Fix userspace free_pages() macroSteven Rostedt
While using etags to find free_pages(), I stumbled across this debug definition of free_pages() that is to be used while debugging some raid code in userspace. The __get_free_pages() allocates the correct size, but the free_pages() does not match. free_pages(), like __get_free_pages(), takes an order and not a size. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md: load/store badblock list from v1.x metadataNeilBrown
Space must have been allocated when array was created. A feature flag is set when the badblock list is non-empty, to ensure old kernels don't load and trust the whole device. We only update the on-disk badblocklist when it has changed. If the badblocklist (or other metadata) is stored on a bad block, we don't cope very well. If metadata has no room for bad block, flag bad-blocks as disabled, and do the same for 0.90 metadata. Signed-off-by: NeilBrown <neilb@suse.de>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-08-12Make lib/raid6/test build correctly.NeilBrown
Some bit-rot needs to be cleaned out. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: remove sparse warning:symbol XXX was not declared.NeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: fix some comments.Andre Noll
1/ Raid5 has learned to take over also raid4 and raid6 arrays. 2/ new_chunk in mdp_superblock_1 is in sectors, not bytes. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid6: move raid6 data processing to raid6_pq.koDan Williams
Move the raid6 data processing routines into a standalone module (raid6_pq) to prepare them to be called from async_tx wrappers and other non-md drivers/modules. This precludes a circular dependency of raid456 needing the async modules for data processing while those modules in turn depend on raid456 for the base level synchronous raid6 routines. To support this move: 1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h 2/ The raid6_call, recovery calls, and table symbols are exported 3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to compile Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move md_k.h from include/linux/raid/ to drivers/md/NeilBrown
It really is nicer to keep related code together.. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move lots of #include lines out of .h files and into .cNeilBrown
This makes the includes more explicit, and is preparation for moving md_k.h to drivers/md/md.h Remove include/raid/md.h as its only remaining use was to #include other files. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move most content from md.h to md_k.hNeilBrown
The extern function definitions are kernel-internal definitions, so they belong in md_k.h The MD_*_VERSION values could reasonably go in a number of places, but md_u.h seems most reasonable. This leaves almost nothing in md.h. It will go soon. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move LEVEL_* definition from md_k.h to md_u.hNeilBrown
.. as they are part of the user-space interface. Also move MdpMinorShift into there so we can remove duplication. Lastly move mdp_major in. It is less obviously part of the user-space interface, but do_mounts_md.c uses it, and it is acting a bit like user-space. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move headers out of include/linux/raid/Christoph Hellwig
Move the headers with the local structures for the disciplines and bitmap.h into drivers/md/ so that they are more easily grepable for hacking and not far away. md.h is left where it is for now as there are some uses from the outside. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Fix is_mddev_idle test (again).NeilBrown
There are two problems with is_mddev_idle. 1/ sync_io is 'atomic_t' and hence 'int'. curr_events and all the rest are 'long'. So if sync_io were to wrap on a 64bit host, the value of curr_events would go very negative suddenly, and take a very long time to return to positive. So do all calculations as 'int'. That gives us plenty of precision for what we need. 2/ To initialise rdev->last_events we simply call is_mddev_idle, on the assumption that it will make sure that last_events is in a suitable range. It used to do this, but now it does not. So now we need to be more explicit about initialisation. Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-30headers_check fix: raid/md_p.hJaswinder Singh Rajput
fix the following 'make headers_check' warning: usr/include/linux/raid/md_p.h:85: found __[us]{8,16,32,64} type without #include <linux/types.h> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
2009-01-09md: don't retry recovery of raid1 that fails due to error on source drive.NeilBrown
If a raid1 has only one working drive and it has a sector which gives an error on read, then an attempt to recover onto a spare will fail, but as the single remaining drive is not removed from the array, the recovery will be immediately re-attempted, resulting in an infinite recovery loop. So detect this situation and don't retry recovery once an error on the lone remaining drive is detected. Allow recovery to be retried once every time a spare is added in case the problem wasn't actually a media error. Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: Allow md devices to be created by name.NeilBrown
Using sequential numbers to identify md devices is somewhat artificial. Using names can be a lot more user-friendly. Also, creating md devices by opening the device special file is a bit awkward. So this patch provides a new option for creating and naming devices. Writing a name such as "md_home" to /sys/modules/md_mod/parameters/new_array will cause an array with that name to be created. It will appear in /sys/block/ /proc/partitions and /proc/mdstat as 'md_home'. It will have an arbitrary minor number allocated. md devices that a created by an open are destroyed on the last close when the device is inactive. For named md devices, they will not be destroyed until the array is explicitly stopped, either with the STOP_ARRAY ioctl or by writing 'clear' to /sys/block/md_XXXX/md/array_state. The name of the array must start 'md_' to avoid conflict with other devices. Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: make devices disappear when they are no longer needed.NeilBrown
Currently md devices, once created, never disappear until the module is unloaded. This is essentially because the gendisk holds a reference to the mddev, and the mddev holds a reference to the gendisk, this a circular reference. If we drop the reference from mddev to gendisk, then we need to ensure that the mddev is destroyed when the gendisk is destroyed. However it is not possible to hook into the gendisk destruction process to enable this. So we drop the reference from the gendisk to the mddev and destroy the gendisk when the mddev gets destroyed. However this has a complication. Between the call __blkdev_get->get_gendisk->kobj_lookup->md_probe and the call __blkdev_get->md_open there is no obvious way to hold a reference on the mddev any more, so unless something is done, it will disappear and gendisk will be destroyed prematurely. Also, once we decide to destroy the mddev, there will be an unlockable moment before the gendisk is unlinked (blk_unregister_region) during which a new reference to the gendisk can be created. We need to ensure that this reference can not be used. i.e. the ->open must fail. So: 1/ in md_probe we set a flag in the mddev (hold_active) which indicates that the array should be treated as active, even though there are no references, and no appearance of activity. This is cleared by md_release when the device is closed if it is no longer needed. This ensures that the gendisk will survive between md_probe and md_open. 2/ In md_open we check if the mddev we expect to open matches the gendisk that we did open. If there is a mismatch we return -ERESTARTSYS and modify __blkdev_get to retry from the top in that case. In the -ERESTARTSYS sys case we make sure to wait until the old gendisk (that we succeeded in opening) is really gone so we loop at most once. Some udev configurations will always open an md device when it first appears. If we allow an md device that was just created by an open to disappear on an immediate close, then this can race with such udev configurations and result in an infinite loop the device being opened and closed, then re-open due to the 'ADD' even from the first open, and then close and so on. So we make sure an md device, once created by an open, remains active at least until some md 'ioctl' has been made on it. This means that all normal usage of md devices will allow them to disappear promptly when not needed, but the worst that an incorrect usage will do it cause an inactive md device to be left in existence (it can easily be removed). As an array can be stopped by writing to a sysfs attribute echo clear > /sys/block/mdXXX/md/array_state we need to use scheduled work for deleting the gendisk and other kobjects. This allows us to wait for any pending gendisk deletion to complete by simply calling flush_scheduled_work(). Signed-off-by: NeilBrown <neilb@suse.de>