1. 24 Jun, 2016 1 commit
    • Michal Hocko's avatar
      tree wide: get rid of __GFP_REPEAT for order-0 allocations part I · 32d6bd90
      Michal Hocko authored
      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.orgSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jan Kara <jack@suse.cz>
      Cc: John Crispin <blogic@openwrt.org>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Fleming <matt@codeblueprint.co.uk>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      32d6bd90
  2. 20 May, 2016 3 commits
    • Zhaoxiu Zeng's avatar
      lib/GCD.c: use binary GCD algorithm instead of Euclidean · fff7fb0b
      Zhaoxiu Zeng authored
      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 <stdio.h>
      	#include <stdlib.h>
      	#include <stdint.h>
      	#include <string.h>
      	#include <time.h>
      	#include <unistd.h>
      
      	#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: default avatarZhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
      Signed-off-by: default avatarGeorge Spelvin <linux@horizon.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fff7fb0b
    • Jiri Slaby's avatar
      exit_thread: accept a task parameter to be exited · e6464694
      Jiri Slaby authored
      We need to call exit_thread from copy_process in a fail path.  So make it
      accept task_struct as a parameter.
      
      [v2]
      * s390: exit_thread_runtime_instr doesn't make sense to be called for
        non-current tasks.
      * arm: fix the comment in vfp_thread_copy
      * change 'me' to 'tsk' for task_struct
      * now we can change only archs that actually have exit_thread
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e6464694
    • Jiri Slaby's avatar
      exit_thread: remove empty bodies · 5f56a5df
      Jiri Slaby authored
      Define HAVE_EXIT_THREAD for archs which want to do something in
      exit_thread. For others, let's define exit_thread as an empty inline.
      
      This is a cleanup before we change the prototype of exit_thread to
      accept a task parameter.
      
      [akpm@linux-foundation.org: fix mips]
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5f56a5df
  3. 19 May, 2016 1 commit
  4. 16 May, 2016 2 commits
    • Arnaldo Carvalho de Melo's avatar
      perf core: Add a 'nr' field to perf_event_callchain_context · 3b1fff08
      Arnaldo Carvalho de Melo authored
      We will use it to count how many addresses are in the entry->ip[] array,
      excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
      return the number of entries specified by the user via the relevant
      sysctl, kernel.perf_event_max_contexts, or via the per event
      perf_event_attr.sample_max_stack knob.
      
      This way we keep the perf_sample->ip_callchain->nr meaning, that is the
      number of entries, be it real addresses or PERF_CONTEXT_ entries, while
      honouring the max_stack knobs, i.e. the end result will be max_stack
      entries if we have at least that many entries in a given stack trace.
      
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      3b1fff08
    • Arnaldo Carvalho de Melo's avatar
      perf core: Pass max stack as a perf_callchain_entry context · cfbcf468
      Arnaldo Carvalho de Melo authored
      This makes perf_callchain_{user,kernel}() receive the max stack
      as context for the perf_callchain_entry, instead of accessing
      the global sysctl_perf_event_max_stack.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Milian Wolff <milian.wolff@kdab.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: Wang Nan <wangnan0@huawei.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      cfbcf468
  5. 04 May, 2016 1 commit
    • James Hogan's avatar
      asm-generic: Drop renameat syscall from default list · b0da6d44
      James Hogan authored
      The newer renameat2 syscall provides all the functionality provided by
      the renameat syscall and adds flags, so future architectures won't need
      to include renameat.
      
      Therefore drop the renameat syscall from the generic syscall list unless
      __ARCH_WANT_RENAMEAT is defined by the architecture's unistd.h prior to
      including asm-generic/unistd.h, and adjust all architectures using the
      generic syscall list to define it so that no in-tree architectures are
      affected.
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Acked-by: default avatarVineet Gupta <vgupta@synopsys.com>
      Cc: linux-arch@vger.kernel.org
      Cc: linux-snps-arc@lists.infradead.org
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-metag@vger.kernel.org
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: linux@lists.openrisc.net
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: nios2-dev@lists.rocketboards.org
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: uclinux-h8-devel@lists.sourceforge.jp
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      b0da6d44
  6. 03 May, 2016 2 commits
    • James Hogan's avatar
      metag: Fix atomic_*_return inline asm constraints · 096a8b6d
      James Hogan authored
      The argument i of atomic_*_return() operations is given to inline asm
      with the "bd" constraint, which means "An Op2 register where Op1 is a
      data unit register and the instruction supports O2R", however Op1 is
      constrained by "da" which allows an address unit register to be used.
      
      Fix the constraint to use "br", meaning "An Op2 register and the
      instruction supports O2R", i.e. not requiring Op1 to be a data unit
      register.
      
      Fixes: d6dfe250 ("locking,arch,metag: Fold atomic_ops")
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: linux-metag@vger.kernel.org
      096a8b6d
    • James Hogan's avatar
      metag: perf: fix build on Meta1 · f5d163aa
      James Hogan authored
      Meta1 doesn't support PERF_ICORE or PERF_CHAN registers resulting in
      build errors due to missing definitions. Fix this with an ifdef matching
      the one in asm/metag_mem.h.
      
      The build errors (found by a randconfig):
      
      arch/metag/kernel/perf/perf_event.c: In function 'metag_pmu_enable_counter':
      arch/metag/kernel/perf/perf_event.c:639: error: 'PERF_ICORE0' undeclared (first use in this function)
      arch/metag/kernel/perf/perf_event.c:639: error: (Each undeclared identifier is reported only once
      arch/metag/kernel/perf/perf_event.c:639: error: for each function it appears in.)
      arch/metag/kernel/perf/perf_event.c:643: error: 'PERF_CHAN0' undeclared (first use in this function)
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      f5d163aa
  7. 29 Apr, 2016 1 commit
  8. 27 Apr, 2016 1 commit
    • Arnaldo Carvalho de Melo's avatar
      perf core: Allow setting up max frame stack depth via sysctl · c5dfd78e
      Arnaldo Carvalho de Melo authored
      The default remains 127, which is good for most cases, and not even hit
      most of the time, but then for some cases, as reported by Brendan, 1024+
      deep frames are appearing on the radar for things like groovy, ruby.
      
      And in some workloads putting a _lower_ cap on this may make sense. One
      that is per event still needs to be put in place tho.
      
      The new file is:
      
        # cat /proc/sys/kernel/perf_event_max_stack
        127
      
      Chaging it:
      
        # echo 256 > /proc/sys/kernel/perf_event_max_stack
        # cat /proc/sys/kernel/perf_event_max_stack
        256
      
      But as soon as there is some event using callchains we get:
      
        # echo 512 > /proc/sys/kernel/perf_event_max_stack
        -bash: echo: write error: Device or resource busy
        #
      
      Because we only allocate the callchain percpu data structures when there
      is a user, which allows for changing the max easily, its just a matter
      of having no callchain users at that point.
      Reported-and-Tested-by: default avatarBrendan Gregg <brendan.d.gregg@gmail.com>
      Reviewed-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Milian Wolff <milian.wolff@kdab.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: Wang Nan <wangnan0@huawei.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c5dfd78e
  9. 26 Apr, 2016 1 commit
  10. 18 Apr, 2016 1 commit
  11. 25 Mar, 2016 1 commit
  12. 17 Mar, 2016 1 commit
  13. 13 Mar, 2016 1 commit
    • Alexander Duyck's avatar
      ipv4: Update parameters for csum_tcpudp_magic to their original types · 01cfbad7
      Alexander Duyck authored
      This patch updates all instances of csum_tcpudp_magic and
      csum_tcpudp_nofold to reflect the types that are usually used as the source
      inputs.  For example the protocol field is populated based on nexthdr which
      is actually an unsigned 8 bit value.  The length is usually populated based
      on skb->len which is an unsigned integer.
      
      This addresses an issue in which the IPv6 function csum_ipv6_magic was
      generating a checksum using the full 32b of skb->len while
      csum_tcpudp_magic was only using the lower 16 bits.  As a result we could
      run into issues when attempting to adjust the checksum as there was no
      protocol agnostic way to update it.
      
      With this change the value is still truncated as many architectures use
      "(len + proto) << 8", however this truncation only occurs for values
      greater than 16776960 in length and as such is unlikely to occur as we stop
      the inner headers at ~64K in size.
      
      I did have to make a few minor changes in the arm, mn10300, nios2, and
      score versions of the function in order to support these changes as they
      were either using things such as an OR to combine the protocol and length,
      or were using ntohs to convert the length which would have truncated the
      value.
      
      I also updated a few spots in terms of whitespace and type differences for
      the addresses.  Most of this was just to make sure all of the definitions
      were in sync going forward.
      Signed-off-by: default avatarAlexander Duyck <aduyck@mirantis.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      01cfbad7
  14. 01 Mar, 2016 1 commit
    • Thomas Gleixner's avatar
      arch/hotplug: Call into idle with a proper state · fc6d73d6
      Thomas Gleixner authored
      Let the non boot cpus call into idle with the corresponding hotplug state, so
      the hotplug core can handle the further bringup. That's a first step to
      convert the boot side of the hotplugged cpus to do all the synchronization
      with the other side through the state machine. For now it'll only start the
      hotplug thread and kick the full bringup of the cpu.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: linux-arch@vger.kernel.org
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
      Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Sebastian Siewior <bigeasy@linutronix.de>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul Turner <pjt@google.com>
      Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      fc6d73d6
  15. 15 Feb, 2016 1 commit
  16. 20 Jan, 2016 2 commits
  17. 16 Jan, 2016 1 commit
  18. 12 Jan, 2016 2 commits
  19. 23 Dec, 2015 1 commit
  20. 04 Dec, 2015 1 commit
  21. 09 Nov, 2015 1 commit
  22. 27 Oct, 2015 2 commits
    • Rob Herring's avatar
      metag: enable building of all dtbs · b02a6875
      Rob Herring authored
      Enable building all dtb files when CONFIG_OF_ALL_DTBS is enabled. The dtbs
      are not really dependent on a platform being enabled or any other kernel
      config, so for testing coverage it is convenient to build all of the dtbs.
      This builds all dts files in the tree, not just targets listed.
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      b02a6875
    • Rob Herring's avatar
      metag: use common make variables for dtb builds · 1aa4c51e
      Rob Herring authored
      Use dtb-y and always make variables to build dtbs instead of explicit
      dtbs rule. This is in preparation to support building all dtbs.
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      1aa4c51e
  23. 23 Sep, 2015 1 commit
    • Peter Zijlstra's avatar
      atomic, arch: Audit atomic_{read,set}() · 62e8a325
      Peter Zijlstra authored
      This patch makes sure that atomic_{read,set}() are at least
      {READ,WRITE}_ONCE().
      
      We already had the 'requirement' that atomic_read() should use
      ACCESS_ONCE(), and most archs had this, but a few were lacking.
      All are now converted to use READ_ONCE().
      
      And, by a symmetry and general paranoia argument, upgrade atomic_set()
      to use WRITE_ONCE().
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: james.hogan@imgtec.com
      Cc: linux-kernel@vger.kernel.org
      Cc: oleg@redhat.com
      Cc: will.deacon@arm.com
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      62e8a325
  24. 16 Sep, 2015 1 commit
    • Thomas Gleixner's avatar
      genirq: Remove irq argument from irq flow handlers · bd0b9ac4
      Thomas Gleixner authored
      Most interrupt flow handlers do not use the irq argument. Those few
      which use it can retrieve the irq number from the irq descriptor.
      
      Remove the argument.
      
      Search and replace was done with coccinelle and some extra helper
      scripts around it. Thanks to Julia for her help!
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Julia Lawall <Julia.Lawall@lip6.fr>
      Cc: Jiang Liu <jiang.liu@linux.intel.com>
      bd0b9ac4
  25. 15 Sep, 2015 2 commits
    • James Hogan's avatar
      metag: Turn irq_ctx_* macros into static inlines · 3dce23eb
      James Hogan authored
      The irq_ctx_init()/irq_ctx_exit() functions are only used for 4KiB
      stacks, otherwise they are implemented as an empty macro. To prevent
      future bit rottage due to the cpu argument not being type checked,
      convert the macros to empty static inline functions.
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      3dce23eb
    • James Hogan's avatar
      metag: SMP: Fix 4KiB stack setup on secondary CPUs · 928df02b
      James Hogan authored
      Back in early 2008, 4KiB stack support was added to reduce memory
      consumption on workloads with lots of threads, using a separate IRQ
      stack per CPU to alleviate stack pressure. However the SMP code added a
      year and a half later didn't set up the IRQ stack when bringing up
      secondary CPUs, resulting in a crash when SMP is configured with 4KiB
      stacks, as soon as the first interrupt arrived on a secondary CPU.
      
      Fix with calls to irq_ctx_exit()/irq_ctx_exit() when bringing up/down a
      CPU.
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      928df02b
  26. 07 Aug, 2015 1 commit
  27. 03 Aug, 2015 1 commit
    • Andrey Konovalov's avatar
      locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire() · 76695af2
      Andrey Konovalov authored
      Replace ACCESS_ONCE() macro in smp_store_release() and smp_load_acquire()
      with WRITE_ONCE() and READ_ONCE() on x86, arm, arm64, ia64, metag, mips,
      powerpc, s390, sparc and asm-generic since ACCESS_ONCE() does not work
      reliably on non-scalar types.
      
      WRITE_ONCE() and READ_ONCE() were introduced in the following commits:
      
        230fa253 ("kernel: Provide READ_ONCE and ASSIGN_ONCE")
        43239cbe ("kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)")
      Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: default avatarDavidlohr Bueso <dbueso@suse.de>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Cc: Alexander Duyck <alexander.h.duyck@redhat.com>
      Cc: Andre Przywara <andre.przywara@arm.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Christian Borntraeger <borntraeger@de.ibm.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arch@vger.kernel.org
      Link: http://lkml.kernel.org/r/1438528264-714-1-git-send-email-andreyknvl@google.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      76695af2
  28. 27 Jul, 2015 3 commits
  29. 20 Jul, 2015 1 commit
  30. 17 Jul, 2015 1 commit