<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/sh, branch v4.7-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild</title>
<updated>2016-05-27T05:01:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-27T05:01:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5b26fc8824da15a2fe9df89338a5a3cad41ba8ee'/>
<id>5b26fc8824da15a2fe9df89338a5a3cad41ba8ee</id>
<content type='text'>
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
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2016-05-26T00:05:40+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-26T00:05:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bdc6b758e443c21c39a14c075e5b7e01f095b37b'/>
<id>bdc6b758e443c21c39a14c075e5b7e01f095b37b</id>
<content type='text'>
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-&gt;name beautifier as default for "filename" args
  perf trace: Use the fd-&gt;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-&gt;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
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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-&gt;name beautifier as default for "filename" args
  perf trace: Use the fd-&gt;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-&gt;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
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>vdso: make arch_setup_additional_pages wait for mmap_sem for write killable</title>
<updated>2016-05-24T00:04:14+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2016-05-23T23:25:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=69048176078adda4087a648c9b1812ddd800fad1'/>
<id>69048176078adda4087a648c9b1812ddd800fad1</id>
<content type='text'>
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 &lt;mhocko@suse.com&gt;
Acked-by: Andy Lutomirski &lt;luto@amacapital.net&gt;	[x86 vdso]
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;mhocko@suse.com&gt;
Acked-by: Andy Lutomirski &lt;luto@amacapital.net&gt;	[x86 vdso]
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch/defconfig: remove CONFIG_RESOURCE_COUNTERS</title>
<updated>2016-05-24T00:04:14+00:00</updated>
<author>
<name>Konstantin Khlebnikov</name>
<email>koct9i@gmail.com</email>
</author>
<published>2016-05-23T23:24:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7efb2a7b85f2d2a53ae50e35cf5df260dd5278b7'/>
<id>7efb2a7b85f2d2a53ae50e35cf5df260dd5278b7</id>
<content type='text'>
This option was replaced by PAGE_COUNTER which is selected by MEMCG.

Signed-off-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This option was replaced by PAGE_COUNTER which is selected by MEMCG.

Signed-off-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>lib/GCD.c: use binary GCD algorithm instead of Euclidean</title>
<updated>2016-05-21T00:58:30+00:00</updated>
<author>
<name>Zhaoxiu Zeng</name>
<email>zhaoxiu.zeng@gmail.com</email>
</author>
<published>2016-05-21T00:03:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fff7fb0b2d908dec779783d8eaf3d7725230f75e'/>
<id>fff7fb0b2d908dec779783d8eaf3d7725230f75e</id>
<content type='text'>
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 &lt;stdio.h&gt;
	#include &lt;stdlib.h&gt;
	#include &lt;stdint.h&gt;
	#include &lt;string.h&gt;
	#include &lt;time.h&gt;
	#include &lt;unistd.h&gt;

	#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 &lt; 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 &gt;&gt;= __builtin_ctzl(b);

		for (;;) {
			a &gt;&gt;= __builtin_ctzl(a);
			if (a == b)
				return a &lt;&lt; __builtin_ctzl(r);

			if (a &lt; 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 &amp;= -r;

		while (!(b &amp; r))
			b &gt;&gt;= 1;

		for (;;) {
			while (!(a &amp; r))
				a &gt;&gt;= 1;
			if (a == b)
				return a;

			if (a &lt; b)
				swap(a, b);
			a -= b;
			a &gt;&gt;= 1;
			if (a &amp; r)
				a += b;
			a &gt;&gt;= 1;
		}
	}

	unsigned long gcd3(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b &gt;&gt;= __builtin_ctzl(b);
		if (b == 1)
			return r &amp; -r;

		for (;;) {
			a &gt;&gt;= __builtin_ctzl(a);
			if (a == 1)
				return r &amp; -r;
			if (a == b)
				return a &lt;&lt; __builtin_ctzl(r);

			if (a &lt; 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 &amp;= -r;

		while (!(b &amp; r))
			b &gt;&gt;= 1;
		if (b == r)
			return r;

		for (;;) {
			while (!(a &amp; r))
				a &gt;&gt;= 1;
			if (a == r)
				return r;
			if (a == b)
				return a;

			if (a &lt; b)
				swap(a, b);
			a -= b;
			a &gt;&gt;= 1;
			if (a &amp; r)
				a += b;
			a &gt;&gt;= 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)&lt;&lt;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 &gt;= 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, &amp;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) &lt; 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() &lt;&lt; 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 &lt; loops; j++) {
			unsigned long a = get_rand();
			/* Do we have args? */
			unsigned long b = argc &gt; optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			unsigned long long min_elapsed[TEST_ENTRIES];
			for (k = 0; k &lt; repeats; k++) {
				for (i = 0; i &lt; TEST_ENTRIES; i++) {
					unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &amp;res[j][i]);
					if (k == 0 || min_elapsed[i] &gt; tmp)
						min_elapsed[i] = tmp;
				}
			}
			for (i = 0; i &lt; TEST_ENTRIES; i++)
				elapsed[i] += min_elapsed[i];
		}

		for (i = 0; i &lt; TEST_ENTRIES; i++)
			printf("gcd%d: elapsed %llu\n", i, elapsed[i]);

		k = 0;
		srand(seed);
		for (j = 0; j &lt; loops; j++) {
			unsigned long a = get_rand();
			unsigned long b = argc &gt; optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			for (i = 1; i &lt; TEST_ENTRIES; i++) {
				if (res[j][i] != res[j][0])
					break;
			}
			if (i &lt; TEST_ENTRIES) {
				if (k == 0) {
					k = 1;
					fprintf(stderr, "Error:\n");
				}
				fprintf(stderr, "gcd(%lu, %lu): ", a, b);
				for (i = 0; i &lt; TEST_ENTRIES; i++)
					fprintf(stderr, "%ld%s", res[j][i], i &lt; 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 &lt;zhaoxiu.zeng@gmail.com&gt;
Signed-off-by: George Spelvin &lt;linux@horizon.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;stdio.h&gt;
	#include &lt;stdlib.h&gt;
	#include &lt;stdint.h&gt;
	#include &lt;string.h&gt;
	#include &lt;time.h&gt;
	#include &lt;unistd.h&gt;

	#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 &lt; 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 &gt;&gt;= __builtin_ctzl(b);

		for (;;) {
			a &gt;&gt;= __builtin_ctzl(a);
			if (a == b)
				return a &lt;&lt; __builtin_ctzl(r);

			if (a &lt; 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 &amp;= -r;

		while (!(b &amp; r))
			b &gt;&gt;= 1;

		for (;;) {
			while (!(a &amp; r))
				a &gt;&gt;= 1;
			if (a == b)
				return a;

			if (a &lt; b)
				swap(a, b);
			a -= b;
			a &gt;&gt;= 1;
			if (a &amp; r)
				a += b;
			a &gt;&gt;= 1;
		}
	}

	unsigned long gcd3(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b &gt;&gt;= __builtin_ctzl(b);
		if (b == 1)
			return r &amp; -r;

		for (;;) {
			a &gt;&gt;= __builtin_ctzl(a);
			if (a == 1)
				return r &amp; -r;
			if (a == b)
				return a &lt;&lt; __builtin_ctzl(r);

			if (a &lt; 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 &amp;= -r;

		while (!(b &amp; r))
			b &gt;&gt;= 1;
		if (b == r)
			return r;

		for (;;) {
			while (!(a &amp; r))
				a &gt;&gt;= 1;
			if (a == r)
				return r;
			if (a == b)
				return a;

			if (a &lt; b)
				swap(a, b);
			a -= b;
			a &gt;&gt;= 1;
			if (a &amp; r)
				a += b;
			a &gt;&gt;= 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)&lt;&lt;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 &gt;= 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, &amp;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) &lt; 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() &lt;&lt; 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 &lt; loops; j++) {
			unsigned long a = get_rand();
			/* Do we have args? */
			unsigned long b = argc &gt; optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			unsigned long long min_elapsed[TEST_ENTRIES];
			for (k = 0; k &lt; repeats; k++) {
				for (i = 0; i &lt; TEST_ENTRIES; i++) {
					unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &amp;res[j][i]);
					if (k == 0 || min_elapsed[i] &gt; tmp)
						min_elapsed[i] = tmp;
				}
			}
			for (i = 0; i &lt; TEST_ENTRIES; i++)
				elapsed[i] += min_elapsed[i];
		}

		for (i = 0; i &lt; TEST_ENTRIES; i++)
			printf("gcd%d: elapsed %llu\n", i, elapsed[i]);

		k = 0;
		srand(seed);
		for (j = 0; j &lt; loops; j++) {
			unsigned long a = get_rand();
			unsigned long b = argc &gt; optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			for (i = 1; i &lt; TEST_ENTRIES; i++) {
				if (res[j][i] != res[j][0])
					break;
			}
			if (i &lt; TEST_ENTRIES) {
				if (k == 0) {
					k = 1;
					fprintf(stderr, "Error:\n");
				}
				fprintf(stderr, "gcd(%lu, %lu): ", a, b);
				for (i = 0; i &lt; TEST_ENTRIES; i++)
					fprintf(stderr, "%ld%s", res[j][i], i &lt; 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 &lt;zhaoxiu.zeng@gmail.com&gt;
Signed-off-by: George Spelvin &lt;linux@horizon.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>printk/nmi: generic solution for safe printk in NMI</title>
<updated>2016-05-21T00:58:30+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2016-05-21T00:00:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=42a0bb3f71383b457a7db362f1c69e7afb96732b'/>
<id>42a0bb3f71383b457a7db362f1c69e7afb96732b</id>
<content type='text'>
printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t-&gt;min - all types are size_t here]
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Suggested-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;	[arm part]
Cc: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Cc: Jiri Kosina &lt;jkosina@suse.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t-&gt;min - all types are size_t here]
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Suggested-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;	[arm part]
Cc: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Cc: Jiri Kosina &lt;jkosina@suse.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>exit_thread: accept a task parameter to be exited</title>
<updated>2016-05-21T00:58:30+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2016-05-21T00:00:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e64646946ed32902fd597fa6e514b1da84642de3'/>
<id>e64646946ed32902fd597fa6e514b1da84642de3</id>
<content type='text'>
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: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Aurelien Jacquiot &lt;a-jacquiot@ti.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@gmail.com&gt;
Cc: Hans-Christian Egtvedt &lt;egtvedt@samfundet.no&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Aurelien Jacquiot &lt;a-jacquiot@ti.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@gmail.com&gt;
Cc: Hans-Christian Egtvedt &lt;egtvedt@samfundet.no&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>exit_thread: remove empty bodies</title>
<updated>2016-05-21T00:58:30+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2016-05-21T00:00:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f56a5dfdb9bcb3bca03df59980d4d2f012cbb53'/>
<id>5f56a5dfdb9bcb3bca03df59980d4d2f012cbb53</id>
<content type='text'>
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: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Aurelien Jacquiot &lt;a-jacquiot@ti.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@gmail.com&gt;
Cc: Hans-Christian Egtvedt &lt;egtvedt@samfundet.no&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Aurelien Jacquiot &lt;a-jacquiot@ti.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@gmail.com&gt;
Cc: Hans-Christian Egtvedt &lt;egtvedt@samfundet.no&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Steven Miao &lt;realmz6@gmail.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf-core-for-mingo-20160516' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core</title>
<updated>2016-05-20T06:20:14+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2016-05-20T06:19:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=21f77d231fabd33c5de61fbff31818d93203353e'/>
<id>21f77d231fabd33c5de61fbff31818d93203353e</id>
<content type='text'>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Honour the kernel.perf_event_max_stack knob more precisely by not counting
  PERF_CONTEXT_{KERNEL,USER} when deciding when to stop adding entries to
  the perf_sample-&gt;ip_callchain[] array (Arnaldo Carvalho de Melo)

- Fix identation of 'stalled-backend-cycles' in 'perf stat' (Namhyung Kim)

- Update runtime using 'cpu-clock' event in 'perf stat' (Namhyung Kim)

- Use 'cpu-clock' for cpu targets in 'perf stat' (Namhyung Kim)

- Avoid fractional digits for integer scales in 'perf stat' (Andi Kleen)

- Store vdso buildid unconditionally, as it appears in callchains and
  we're not checking those when creating the build-id table, so we
  end up not being able to resolve VDSO symbols when doing analysis
  on a different machine than the one where recording was done, possibly
  of a different arch even (arm -&gt; x86_64) (He Kuang)

Infrastructure changes:

- Generalize max_stack sysctl handler, will be used for configuring
  multiple kernel knobs related to callchains (Arnaldo Carvalho de Melo)

Cleanups:

- Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE, to stop using
  open coded strings (Masami Hiramatsu)

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Honour the kernel.perf_event_max_stack knob more precisely by not counting
  PERF_CONTEXT_{KERNEL,USER} when deciding when to stop adding entries to
  the perf_sample-&gt;ip_callchain[] array (Arnaldo Carvalho de Melo)

- Fix identation of 'stalled-backend-cycles' in 'perf stat' (Namhyung Kim)

- Update runtime using 'cpu-clock' event in 'perf stat' (Namhyung Kim)

- Use 'cpu-clock' for cpu targets in 'perf stat' (Namhyung Kim)

- Avoid fractional digits for integer scales in 'perf stat' (Andi Kleen)

- Store vdso buildid unconditionally, as it appears in callchains and
  we're not checking those when creating the build-id table, so we
  end up not being able to resolve VDSO symbols when doing analysis
  on a different machine than the one where recording was done, possibly
  of a different arch even (arm -&gt; x86_64) (He Kuang)

Infrastructure changes:

- Generalize max_stack sysctl handler, will be used for configuring
  multiple kernel knobs related to callchains (Arnaldo Carvalho de Melo)

Cleanups:

- Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE, to stop using
  open coded strings (Masami Hiramatsu)

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio</title>
<updated>2016-05-18T00:39:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-18T00:39:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1eccc6e1529ec7ad1cebbd2c97ceb2a1a39f7d76'/>
<id>1eccc6e1529ec7ad1cebbd2c97ceb2a1a39f7d76</id>
<content type='text'>
Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...
</pre>
</div>
</content>
</entry>
</feed>
