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  1. 05 10月, 2011 10 次提交
  3. 04 10月, 2011 12 次提交
  5. 03 10月, 2011 5 次提交
  7. 02 10月, 2011 1 次提交
  9. 01 10月, 2011 3 次提交
  11. 30 9月, 2011 9 次提交
    • P
      posix-cpu-timers: Cure SMP wobbles · d670ec13
      由 Peter Zijlstra 提交于 
      David reported:

  Attached below is a watered-down version of rt/tst-cpuclock2.c from
  GLIBC.  Just build it with "gcc -o test test.c -lpthread -lrt" or
  similar.

  Run it several times, and you will see cases where the main thread
  will measure a process clock difference before and after the nanosleep
  which is smaller than the cpu-burner thread's individual thread clock
  difference.  This doesn't make any sense since the cpu-burner thread
  is part of the top-level process's thread group.

  I've reproduced this on both x86-64 and sparc64 (using both 32-bit and
  64-bit binaries).

  For example:

  [davem@boricha build-x86_64-linux]$ ./test
  process: before(0.001221967) after(0.498624371) diff(497402404)
  thread:  before(0.000081692) after(0.498316431) diff(498234739)
  self:    before(0.001223521) after(0.001240219) diff(16698)
  [davem@boricha build-x86_64-linux]$ 

  The diff of 'process' should always be >= the diff of 'thread'.

  I make sure to wrap the 'thread' clock measurements the most tightly
  around the nanosleep() call, and that the 'process' clock measurements
  are the outer-most ones.

  ---
  #include <unistd.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <time.h>
  #include <fcntl.h>
  #include <string.h>
  #include <errno.h>
  #include <pthread.h>

  static pthread_barrier_t barrier;

  static void *chew_cpu(void *arg)
  {
	  pthread_barrier_wait(&barrier);
	  while (1)
		  __asm__ __volatile__("" : : : "memory");
	  return NULL;
  }

  int main(void)
  {
	  clockid_t process_clock, my_thread_clock, th_clock;
	  struct timespec process_before, process_after;
	  struct timespec me_before, me_after;
	  struct timespec th_before, th_after;
	  struct timespec sleeptime;
	  unsigned long diff;
	  pthread_t th;
	  int err;

	  err = clock_getcpuclockid(0, &process_clock);
	  if (err)
		  return 1;

	  err = pthread_getcpuclockid(pthread_self(), &my_thread_clock);
	  if (err)
		  return 1;

	  pthread_barrier_init(&barrier, NULL, 2);
	  err = pthread_create(&th, NULL, chew_cpu, NULL);
	  if (err)
		  return 1;

	  err = pthread_getcpuclockid(th, &th_clock);
	  if (err)
		  return 1;

	  pthread_barrier_wait(&barrier);

	  err = clock_gettime(process_clock, &process_before);
	  if (err)
		  return 1;

	  err = clock_gettime(my_thread_clock, &me_before);
	  if (err)
		  return 1;

	  err = clock_gettime(th_clock, &th_before);
	  if (err)
		  return 1;

	  sleeptime.tv_sec = 0;
	  sleeptime.tv_nsec = 500000000;
	  nanosleep(&sleeptime, NULL);

	  err = clock_gettime(th_clock, &th_after);
	  if (err)
		  return 1;

	  err = clock_gettime(my_thread_clock, &me_after);
	  if (err)
		  return 1;

	  err = clock_gettime(process_clock, &process_after);
	  if (err)
		  return 1;

	  diff = process_after.tv_nsec - process_before.tv_nsec;
	  printf("process: before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n",
		 process_before.tv_sec, process_before.tv_nsec,
		 process_after.tv_sec, process_after.tv_nsec, diff);
	  diff = th_after.tv_nsec - th_before.tv_nsec;
	  printf("thread:  before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n",
		 th_before.tv_sec, th_before.tv_nsec,
		 th_after.tv_sec, th_after.tv_nsec, diff);
	  diff = me_after.tv_nsec - me_before.tv_nsec;
	  printf("self:    before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n",
		 me_before.tv_sec, me_before.tv_nsec,
		 me_after.tv_sec, me_after.tv_nsec, diff);

	  return 0;
  }

This is due to us using p->se.sum_exec_runtime in
thread_group_cputime() where we iterate the thread group and sum all
data. This does not take time since the last schedule operation (tick
or otherwise) into account. We can cure this by using
task_sched_runtime() at the cost of having to take locks.

This also means we can (and must) do away with
thread_group_sched_runtime() since the modified thread_group_cputime()
is now more accurate and would deadlock when called from
thread_group_sched_runtime().

Aside of that it makes the function safe on 32 bit systems. The old
code added t->se.sum_exec_runtime unprotected. sum_exec_runtime is a
64bit value and could be changed on another cpu at the same time.
Reported-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1314874459.7945.22.camel@twinsTested-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      d670ec13
    • T
      ALSA: hda - Fix a regression of the position-buffer check · 798cb7e8
      由 Takashi Iwai 提交于 
      The commit a810364a
    ALSA: hda - Handle -1 as invalid position, too
caused a regression on some machines that require the position-buffer
instead of LPIB, e.g. resulting in noises with mic recording with
PulseAudio.

This patch fixes the detection by delaying the test at the timing as
same as 3.0, i.e. doing the position check only when requested in
azx_position_ok().
Reported-and-tested-by: NRocko Requin <rockorequin@hotmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      798cb7e8
    • R
      Resource: fix wrong resource window calculation · 47ea91b4
      由 Ram Pai 提交于 
      __find_resource() incorrectly returns a resource window which overlaps
an existing allocated window.  This happens when the parent's
resource-window spans 0x00000000 to 0xffffffff and is entirely allocated
to all its children resource-windows.

__find_resource() looks for gaps in resource allocation among the
children resource windows.  When it encounters the last child window it
blindly tries the range next to one allocated to the last child.  Since
the last child's window ends at 0xffffffff the calculation overflows,
leading the algorithm to believe that any window in the range 0x0000000
to 0xfffffff is available for allocation.  This leads to a conflicting
window allocation.

Michal Ludvig reported this issue seen on his platform.  The following
patch fixes the problem and has been verified by Michal.  I believe this
bug has been there for ages.  It got exposed by git commit 2bbc6942
("PCI : ability to relocate assigned pci-resources")
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Tested-by: NMichal Ludvig <mludvig@logix.net.nz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      47ea91b4
    • L
      Merge branch 'for-linus' of git://github.com/NewDreamNetwork/ceph-client · 92bb062f
      由 Linus Torvalds 提交于 
      * 'for-linus' of git://github.com/NewDreamNetwork/ceph-client:
  libceph: fix pg_temp mapping update
  libceph: fix pg_temp mapping calculation
  libceph: fix linger request requeuing
  libceph: fix parse options memory leak
  libceph: initialize ack_stamp to avoid unnecessary connection reset
      92bb062f
    • L
      Merge branch 'v4l_for_linus' of git://linuxtv.org/mchehab/for_linus · 7409b713
      由 Linus Torvalds 提交于 
      * 'v4l_for_linus' of git://linuxtv.org/mchehab/for_linus:
  [media] omap3isp: Fix build error in ispccdc.c
  [media] uvcvideo: Fix crash when linking entities
  [media] v4l: Make sure we hold a reference to the v4l2_device before using it
  [media] v4l: Fix use-after-free case in v4l2_device_release
  [media] uvcvideo: Set alternate setting 0 on resume if the bus has been reset
  [media] OMAP_VOUT: Fix build break caused by update_mode removal in DSS2
      7409b713
    • L
      Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 · 0ecdb12a
      由 Linus Torvalds 提交于 
      * 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] cio: fix cio_tpi ignoring adapter interrupts
  [S390] gmap: always up mmap_sem properly
  [S390] Do not clobber personality flags on exec
      0ecdb12a
    • L
      Merge git://github.com/davem330/sparc · 5fe858b5
      由 Linus Torvalds 提交于 
      * git://github.com/davem330/sparc:
  sparc64: Force the execute bit in OpenFirmware's translation entries.
  sparc: Make '-p' boot option meaningful again.
  sparc, exec: remove redundant addr_limit assignment
  sparc64: Future proof Niagara cpu detection.
      5fe858b5
    • L
      Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~keithp/linux · 8e8e500f
      由 Linus Torvalds 提交于 
      * 'drm-intel-fixes' of git://people.freedesktop.org/~keithp/linux:
  drm/i915: FBC off for ironlake and older, otherwise on by default
  drm/i915: Enable SDVO hotplug interrupts for HDMI and DVI
  drm/i915: Enable dither whenever display bpc < frame buffer bpc
      8e8e500f
    • B
      powerpc: Fix device-tree matching for Apple U4 bridge · 16fa42af
      由 Benjamin Herrenschmidt 提交于 
      Apple Quad G5 has some oddity in it's device-tree which causes the new
generic matching code to fail to relate nodes for PCI-E devices below U4
with their respective struct pci_dev.  This breaks graphics on those
machines among others.

This fixes it using a quirk which copies the node pointer from the host
bridge for the root complex, which makes the generic code work for the
children afterward.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      16fa42af