BMC/Intel-BMC/linux.git/arch/sh, branch dev-4.7

sh: cmpxchg: fix a bit shift bug in big_endian os

2016-09-24T08:09:39+00:00

commit ff18143ceed3424b7d6cdb8659b9692fa734f0d8 upstream. Correct bitoff in big endian OS. Current code works correctly for 1 byte but not for 2 bytes. Fixes: 3226aad81aa6 ("sh: support 1 and 2 byte xchg") Signed-off-by: Pan Xinhui Acked-by: Michael S. Tsirkin Signed-off-by: Rich Felker Signed-off-by: Greg Kroah-Hartman

sh: fix copy_from_user()

2016-09-24T08:09:39+00:00

commit 6e050503a150b2126620c1a1e9b3a368fcd51eac upstream. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

sh64: failing __get_user() should zero

2016-09-24T08:09:38+00:00

commit c6852389228df9fb3067f94f3b651de2a7921b36 upstream. It could be done in exception-handling bits in __get_user_b() et.al., but the surgery involved would take more knowledge of sh64 details than I have or _want_ to have. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

sh: get rid of superfluous __GFP_REPEAT

2016-06-25T00:23:52+00:00

__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. PGALLOC_GFP uses __GFP_REPEAT but {pgd,pmd}_alloc allocate from {pgd,pmd}_cache but both caches are allocating up to PAGE_SIZE objects. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-15-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko Cc: Yoshinori Sato Cc: Rich Felker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tree wide: get rid of __GFP_REPEAT for order-0 allocations part I

2016-06-25T00:23:52+00:00

This is the third version of the patchset previously sent [1]. I have basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get rid of superfluous gfp flags" which went through dm tree. I am sending it now because it is tree wide and chances for conflicts are reduced considerably when we want to target rc2. I plan to send the next step and rename the flag and move to a better semantic later during this release cycle so we will have a new semantic ready for 4.8 merge window hopefully. Motivation: While working on something unrelated I've checked the current usage of __GFP_REPEAT in the tree. It seems that a majority of the usage is and always has been bogus because __GFP_REPEAT has always been about costly high order allocations while we are using it for order-0 or very small orders very often. It seems that a big pile of them is just a copy&paste when a code has been adopted from one arch to another. I think it makes some sense to get rid of them because they are just making the semantic more unclear. Please note that GFP_REPEAT is documented as * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt * _might_ fail. This depends upon the particular VM implementation. while !costly requests have basically nofail semantic. So one could reasonably expect that order-0 request with __GFP_REPEAT will not loop for ever. This is not implemented right now though. I would like to move on with __GFP_REPEAT and define a better semantic for it. $ git grep __GFP_REPEAT origin/master | wc -l 111 $ git grep __GFP_REPEAT | wc -l 36 So we are down to the third after this patch series. The remaining places really seem to be relying on __GFP_REPEAT due to large allocation requests. This still needs some double checking which I will do later after all the simple ones are sorted out. I am touching a lot of arch specific code here and I hope I got it right but as a matter of fact I even didn't compile test for some archs as I do not have cross compiler for them. Patches should be quite trivial to review for stupid compile mistakes though. The tricky parts are usually hidden by macro definitions and thats where I would appreciate help from arch maintainers. [1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org This patch (of 19): __GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. Yet we have the full kernel tree with its usage for apparently order-0 allocations. This is really confusing because __GFP_REPEAT is explicitly documented to allow allocation failures which is a weaker semantic than the current order-0 has (basically nofail). Let's simply drop __GFP_REPEAT from those places. This would allow to identify place which really need allocator to retry harder and formulate a more specific semantic for what the flag is supposed to do actually. Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko Cc: "David S. Miller" Cc: "H. Peter Anvin" Cc: "James E.J. Bottomley" Cc: "Theodore Ts'o" Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Chen Liqin Cc: Chris Metcalf [for tile] Cc: Guan Xuetao Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Jan Kara Cc: John Crispin Cc: Lennox Wu Cc: Ley Foon Tan Cc: Martin Schwidefsky Cc: Matt Fleming Cc: Ralf Baechle Cc: Rich Felker Cc: Russell King Cc: Thomas Gleixner Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-05-27T05:01:22+00:00

Pull kbuild updates from Michal Marek: - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and unexports symbols which are not used in the current config [Nicolas Pitre] - several kbuild rule cleanups [Masahiro Yamada] - warning option adjustments for gcov etc [Arnd Bergmann] - a few more small fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits) kbuild: move -Wunused-const-variable to W=1 warning level kbuild: fix if_change and friends to consider argument order kbuild: fix adjust_autoksyms.sh for modules that need only one symbol kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line gcov: disable -Wmaybe-uninitialized warning gcov: disable tree-loop-im to reduce stack usage gcov: disable for COMPILE_TEST Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES Kbuild: change CC_OPTIMIZE_FOR_SIZE definition kbuild: forbid kernel directory to contain spaces and colons kbuild: adjust ksym_dep_filter for some cmd_* renames kbuild: Fix dependencies for final vmlinux link kbuild: better abstract vmlinux sequential prerequisites kbuild: fix call to adjust_autoksyms.sh when output directory specified kbuild: Get rid of KBUILD_STR kbuild: rename cmd_as_s_S to cmd_cpp_s_S kbuild: rename cmd_cc_i_c to cmd_cpp_i_c kbuild: drop redundant "PHONY += FORCE" kbuild: delete unnecessary "@:" kbuild: mark help target as PHONY ...

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-05-26T00:05:40+00:00

Pull perf updates from Ingo Molnar: "Mostly tooling and PMU driver fixes, but also a number of late updates such as the reworking of the call-chain size limiting logic to make call-graph recording more robust, plus tooling side changes for the new 'backwards ring-buffer' extension to the perf ring-buffer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) perf record: Read from backward ring buffer perf record: Rename variable to make code clear perf record: Prevent reading invalid data in record__mmap_read perf evlist: Add API to pause/resume perf trace: Use the ptr->name beautifier as default for "filename" args perf trace: Use the fd->name beautifier as default for "fd" args perf report: Add srcline_from/to branch sort keys perf evsel: Record fd into perf_mmap perf evsel: Add overwrite attribute and check write_backward perf tools: Set buildid dir under symfs when --symfs is provided perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced perf annotate: Sort list of recognised instructions perf annotate: Fix identification of ARM blt and bls instructions perf tools: Fix usage of max_stack sysctl perf callchain: Stop validating callchains by the max_stack sysctl perf trace: Fix exit_group() formatting perf top: Use machine->kptr_restrict_warned perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1 perf machine: Do not bail out if not managing to read ref reloc symbol perf/x86/intel/p4: Trival indentation fix, remove space ...

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2016-05-24T00:04:14+00:00

most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko Acked-by: Andy Lutomirski [x86 vdso] Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch/defconfig: remove CONFIG_RESOURCE_COUNTERS

2016-05-24T00:04:14+00:00

This option was replaced by PAGE_COUNTER which is selected by MEMCG. Signed-off-by: Konstantin Khlebnikov Acked-by: Arnd Bergmann Acked-by: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/GCD.c: use binary GCD algorithm instead of Euclidean

2016-05-21T00:58:30+00:00

The binary GCD algorithm is based on the following facts: 1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2) 2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b) 3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b) Even on x86 machines with reasonable division hardware, the binary algorithm runs about 25% faster (80% the execution time) than the division-based Euclidian algorithm. On platforms like Alpha and ARMv6 where division is a function call to emulation code, it's even more significant. There are two variants of the code here, depending on whether a fast __ffs (find least significant set bit) instruction is available. This allows the unpredictable branches in the bit-at-a-time shifting loop to be eliminated. If fast __ffs is not available, the "even/odd" GCD variant is used. I use the following code to benchmark: #include #include #include #include #include #include #define swap(a, b) \ do { \ a ^= b; \ b ^= a; \ a ^= b; \ } while (0) unsigned long gcd0(unsigned long a, unsigned long b) { unsigned long r; if (a < b) { swap(a, b); } if (b == 0) return a; while ((r = a % b) != 0) { a = b; b = r; } return b; } unsigned long gcd1(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); for (;;) { a >>= __builtin_ctzl(a); if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd2(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; for (;;) { while (!(a & r)) a >>= 1; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } unsigned long gcd3(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); if (b == 1) return r & -r; for (;;) { a >>= __builtin_ctzl(a); if (a == 1) return r & -r; if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd4(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = { gcd0, gcd1, gcd2, gcd3, gcd4, }; #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0])) #if defined(__x86_64__) #define rdtscll(val) do { \ unsigned long __a,__d; \ __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \ (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \ } while(0) static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { unsigned long long start, end; unsigned long long ret; unsigned long gcd_res; rdtscll(start); gcd_res = gcd(a, b); rdtscll(end); if (end >= start) ret = end - start; else ret = ~0ULL - start + 1 + end; *res = gcd_res; return ret; } #else static inline struct timespec read_time(void) { struct timespec time; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time); return time; } static inline unsigned long long diff_time(struct timespec start, struct timespec end) { struct timespec temp; if ((end.tv_nsec - start.tv_nsec) < 0) { temp.tv_sec = end.tv_sec - start.tv_sec - 1; temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec; } else { temp.tv_sec = end.tv_sec - start.tv_sec; temp.tv_nsec = end.tv_nsec - start.tv_nsec; } return temp.tv_sec * 1000000000ULL + temp.tv_nsec; } static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { struct timespec start, end; unsigned long gcd_res; start = read_time(); gcd_res = gcd(a, b); end = read_time(); *res = gcd_res; return diff_time(start, end); } #endif static inline unsigned long get_rand() { if (sizeof(long) == 8) return (unsigned long)rand() << 32 | rand(); else return rand(); } int main(int argc, char **argv) { unsigned int seed = time(0); int loops = 100; int repeats = 1000; unsigned long (*res)[TEST_ENTRIES]; unsigned long long elapsed[TEST_ENTRIES]; int i, j, k; for (;;) { int opt = getopt(argc, argv, "n:r:s:"); /* End condition always first */ if (opt == -1) break; switch (opt) { case 'n': loops = atoi(optarg); break; case 'r': repeats = atoi(optarg); break; case 's': seed = strtoul(optarg, NULL, 10); break; default: /* You won't actually get here. */ break; } } res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops); memset(elapsed, 0, sizeof(elapsed)); srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); /* Do we have args? */ unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); unsigned long long min_elapsed[TEST_ENTRIES]; for (k = 0; k < repeats; k++) { for (i = 0; i < TEST_ENTRIES; i++) { unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]); if (k == 0 || min_elapsed[i] > tmp) min_elapsed[i] = tmp; } } for (i = 0; i < TEST_ENTRIES; i++) elapsed[i] += min_elapsed[i]; } for (i = 0; i < TEST_ENTRIES; i++) printf("gcd%d: elapsed %llu\n", i, elapsed[i]); k = 0; srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); for (i = 1; i < TEST_ENTRIES; i++) { if (res[j][i] != res[j][0]) break; } if (i < TEST_ENTRIES) { if (k == 0) { k = 1; fprintf(stderr, "Error:\n"); } fprintf(stderr, "gcd(%lu, %lu): ", a, b); for (i = 0; i < TEST_ENTRIES; i++) fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n"); } } if (k == 0) fprintf(stderr, "PASS\n"); free(res); return 0; } Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got: zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 10174 gcd1: elapsed 2120 gcd2: elapsed 2902 gcd3: elapsed 2039 gcd4: elapsed 2812 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9309 gcd1: elapsed 2280 gcd2: elapsed 2822 gcd3: elapsed 2217 gcd4: elapsed 2710 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9589 gcd1: elapsed 2098 gcd2: elapsed 2815 gcd3: elapsed 2030 gcd4: elapsed 2718 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9914 gcd1: elapsed 2309 gcd2: elapsed 2779 gcd3: elapsed 2228 gcd4: elapsed 2709 PASS [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable] Signed-off-by: Zhaoxiu Zeng Signed-off-by: George Spelvin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds