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  1. 04 Oct, 2011 10 commits
  3. 03 Oct, 2011 13 commits
  5. 02 Oct, 2011 1 commit
  7. 01 Oct, 2011 1 commit
  9. 30 Sep, 2011 12 commits
    • Josef Bacik's avatar
      Btrfs: force a page fault if we have a shorty copy on a page boundary · b6316429
      Josef Bacik authored 
      A user reported a problem where ceph was getting into 100% cpu usage while doing
some writing.  It turns out it's because we were doing a short write on a not
uptodate page, which means we'd fall back at one page at a time and fault the
page in.  The problem is our position is on the page boundary, so our fault in
logic wasn't actually reading the page, so we'd just spin forever or until the
page got read in by somebody else.  This will force a readpage if we end up
doing a short copy.  Alexandre could reproduce this easily with ceph and reports
it fixes his problem.  I also wrote a reproducer that no longer hangs my box
with this patch.  Thanks,
Reported-and-tested-by: default avatarAlexandre Oliva <aoliva@redhat.com>
Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      b6316429
    • Ingo Molnar's avatar
      Merge branch 'perf/urgent' of git://github.com/acmel/linux into perf/urgent · 9d3ec7a0
      Ingo Molnar authored
      9d3ec7a0
    • Peter Zijlstra's avatar
      posix-cpu-timers: Cure SMP wobbles · d670ec13
      Peter Zijlstra authored 
      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: default avatarDavid Miller <davem@davemloft.net>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1314874459.7945.22.camel@twinsTested-by: default avatarDavid Miller <davem@davemloft.net>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      d670ec13
    • Takashi Iwai's avatar
      ALSA: hda - Fix a regression of the position-buffer check · 798cb7e8
      Takashi Iwai authored 
      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: default avatarRocko Requin <rockorequin@hotmail.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      798cb7e8
    • Ram Pai's avatar
      Resource: fix wrong resource window calculation · 47ea91b4
      Ram Pai authored 
      __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: default avatarRam Pai <linuxram@us.ibm.com>
Tested-by: default avatarMichal Ludvig <mludvig@logix.net.nz>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      47ea91b4
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://github.com/NewDreamNetwork/ceph-client · 92bb062f
      Linus Torvalds authored 
      * '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
    • Linus Torvalds's avatar
      Merge branch 'v4l_for_linus' of git://linuxtv.org/mchehab/for_linus · 7409b713
      Linus Torvalds authored 
      * '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
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 · 0ecdb12a
      Linus Torvalds authored 
      * '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
    • Linus Torvalds's avatar
      Merge git://github.com/davem330/sparc · 5fe858b5
      Linus Torvalds authored 
      * 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
    • Linus Torvalds's avatar
      Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~keithp/linux · 8e8e500f
      Linus Torvalds authored 
      * '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
    • Benjamin Herrenschmidt's avatar
      powerpc: Fix device-tree matching for Apple U4 bridge · 16fa42af
      Benjamin Herrenschmidt authored 
      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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      16fa42af
    • wangyanqing's avatar
      bootup: move 'usermodehelper_enable()' a little earlier · b0f84374
      wangyanqing authored 
      Commit d5767c53 ("bootup: move 'usermodehelper_enable()' to the end
of do_basic_setup()") moved 'usermodehelper_enable()' to end of
do_basic_setup() to after the initcalls.  But then I get failed to let
uvesafb work on my computer, and lose the splash boot.

So maybe we could start usermodehelper_enable a little early to make
some task work that need eary init with the help of user mode.

[ I would *really* prefer that initcalls not call into user space - even
  the real 'init' hasn't been execve'd yet, after all! But for uvesafb
  it really does look like we don't have much choice.

  I considered doing this when we mount the root filesystem, but
  depending on config options that is in multiple places.  We could do
  the usermode helper enable as a rootfs_initcall()..

  So I'm just using wang yanqing's trivial patch.  It's not wonderful,
  but it's simple and should work.  We should revisit this some day,
  though.      - Linus ]
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b0f84374
  11. 29 Sep, 2011 2 commits
    • Jiri Olsa's avatar
      perf tools: Fix raw sample reading · 8e303f20
      Jiri Olsa authored 
      Wrong pointer is being passed for raw data sanity checking, when parsing
sample event.

This ends up with invalid event and perf record being stuck in
__perf_session__process_events function during processing build IDs
(process_buildids function).

Following command hangs up in my setup:
	./perf record -e raw_syscalls:sys_enter ls

The fix is to use proper pointer to the raw data instead of the 'u'
union.
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1317308709-9474-2-git-send-email-jolsa@redhat.comSigned-off-by: default avatarJiri Olsa <jolsa@redhat.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8e303f20
    • David S. Miller's avatar
      sparc64: Force the execute bit in OpenFirmware's translation entries. · f4142cba
      David S. Miller authored 
      In the OF 'translations' property, the template TTEs in the mappings
never specify the executable bit.  This is the case even though some
of these mappings are for OF's code segment.

Therefore, we need to force the execute bit on in every mapping.

This problem can only really trigger on Niagara/sun4v machines and the
history behind this is a little complicated.

Previous to sun4v, the sun4u TTE entries lacked a hardware execute
permission bit.  So OF didn't have to ever worry about setting
anything to handle executable pages.  Any valid TTE loaded into the
I-TLB would be respected by the chip.

But sun4v Niagara chips have a real hardware enforced executable bit
in their TTEs.  So it has to be set or else the I-TLB throws an
instruction access exception with type code 6 (protection violation).

We've been extremely fortunate to not get bitten by this in the past.

The best I can tell is that the OF's mappings for it's executable code
were mapped using permanent locked mappings on sun4v in the past.
Therefore, the fact that we didn't have the exec bit set in the OF
translations we would use did not matter in practice.

Thanks to Greg Onufer for helping me track this down.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f4142cba
  13. 28 Sep, 2011 1 commit
    • Linus Torvalds's avatar
      bootup: move 'usermodehelper_enable()' to the end of do_basic_setup() · d5767c53
      Linus Torvalds authored 
      Doing it just before starting to call into cpu_idle() made a sick kind
of sense only because the original bug we fixed (see commit
288d5abe: "Boot up with usermodehelper disabled") was about problems
with some scheduler data structures not being initialized, and they had
better be initialized at that point.

But it really didn't make any other conceptual sense, and doing it after
the initial "schedule()" call for the idle thread actually opened up a
race: what if the main initialization thread did everything without
needing to sleep, and got all the way into user land too? Without
actually having scheduled back to the idle thread?

Now, in normal circumstances that doesn't ever happen, but it looks like
Richard Cochran triggered exactly that on his ARM IXP4xx machines:

  "I have some ARM IXP4xx based machines that use the two on chip MAC
   ports (aka NPEs).  The NPE needs a firmware in order to function.
   Ever since the following commit [that 288d5abe one], it is no
   longer possible to bring up the interfaces during the init scripts."

with a call trace showing an ioctl coming from user space. Richard says:

  "The init is busybox, and the startup script does mount, syslogd, and
   then ifup, so that all can go by quickly."

The fix is to move the usermodehelper_enable() into the main 'init'
thread, and just put it after we've done all our initcalls.  By then,
everything really should be up, but we've obviously not actually started
the user-mode portion of init yet.
Reported-and-tested-by: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d5767c53
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