<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/time/timer_list.c, branch v5.10-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>timer_list: Guard procfs specific code</title>
<updated>2019-06-22T22:08:52+00:00</updated>
<author>
<name>Nathan Huckleberry</name>
<email>nhuck@google.com</email>
</author>
<published>2019-06-14T18:16:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a9314773a91a1d3b36270085246a6715a326ff00'/>
<id>a9314773a91a1d3b36270085246a6715a326ff00</id>
<content type='text'>
With CONFIG_PROC_FS=n the following warning is emitted:

kernel/time/timer_list.c:361:36: warning: unused variable
'timer_list_sops' [-Wunused-const-variable]
   static const struct seq_operations timer_list_sops = {

Add #ifdef guard around procfs specific code.

Signed-off-by: Nathan Huckleberry &lt;nhuck@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: clang-built-linux@googlegroups.com
Link: https://github.com/ClangBuiltLinux/linux/issues/534
Link: https://lkml.kernel.org/r/20190614181604.112297-1-nhuck@google.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With CONFIG_PROC_FS=n the following warning is emitted:

kernel/time/timer_list.c:361:36: warning: unused variable
'timer_list_sops' [-Wunused-const-variable]
   static const struct seq_operations timer_list_sops = {

Add #ifdef guard around procfs specific code.

Signed-off-by: Nathan Huckleberry &lt;nhuck@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: clang-built-linux@googlegroups.com
Link: https://github.com/ClangBuiltLinux/linux/issues/534
Link: https://lkml.kernel.org/r/20190614181604.112297-1-nhuck@google.com

</pre>
</div>
</content>
</entry>
<entry>
<title>hrtimers/tick/clockevents: Remove sloppy license references</title>
<updated>2018-11-23T10:51:21+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2018-10-31T18:21:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f49c174b5f431db9fa17315269e288d4548b651c'/>
<id>f49c174b5f431db9fa17315269e288d4548b651c</id>
<content type='text'>
"For licencing details see kernel-base/COPYING" and similar license
references have no value over the SPDX identifier. Remove them.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Nicolas Pitre &lt;nicolas.pitre@linaro.org&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181031182252.963632760@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
"For licencing details see kernel-base/COPYING" and similar license
references have no value over the SPDX identifier. Remove them.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Nicolas Pitre &lt;nicolas.pitre@linaro.org&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181031182252.963632760@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>time: Add SPDX license identifiers</title>
<updated>2018-11-23T10:51:20+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2018-10-31T18:21:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=35728b8209ee7d25b6241a56304ee926469bd154'/>
<id>35728b8209ee7d25b6241a56304ee926469bd154</id>
<content type='text'>
Update the time(r) core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of the
full boiler plate text.

This work is based on a script and data from Philippe Ombredanne, Kate
Stewart and myself. The data has been created with two independent license
scanners and manual inspection.

The following files do not contain any direct license information and have
been omitted from the big initial SPDX changes:

  timeconst.bc: The .bc files were not touched
  time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL

As those files do not contain direct license references they fall under the
project license, i.e. GPL V2 only.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: Nicolas Pitre &lt;nicolas.pitre@linaro.org&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update the time(r) core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of the
full boiler plate text.

This work is based on a script and data from Philippe Ombredanne, Kate
Stewart and myself. The data has been created with two independent license
scanners and manual inspection.

The following files do not contain any direct license information and have
been omitted from the big initial SPDX changes:

  timeconst.bc: The .bc files were not touched
  time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL

As those files do not contain direct license references they fall under the
project license, i.e. GPL V2 only.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: Nicolas Pitre &lt;nicolas.pitre@linaro.org&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>time: Remove useless filenames in top level comments</title>
<updated>2018-11-23T10:51:20+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2018-10-31T18:21:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=58c5fc2b96e4ae65068d815a1c3ca81da92fa1c9'/>
<id>58c5fc2b96e4ae65068d815a1c3ca81da92fa1c9</id>
<content type='text'>
Remove the pointless filenames in the top level comments. They have no
value at all and just occupy space. While at it tidy up some of the
comments and remove a stale one.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181031182252.794898238@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove the pointless filenames in the top level comments. They have no
value at all and just occupy space. While at it tidy up some of the
comments and remove a stale one.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Acked-by: John Stultz &lt;john.stultz@linaro.org&gt;
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Cc: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Cc: Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: David Riley &lt;davidriley@chromium.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181031182252.794898238@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2018-06-05T03:27:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-06-05T03:27:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0bbcce5d1ef3f771a349896f1c7574d20dc6f4bd'/>
<id>0bbcce5d1ef3f771a349896f1c7574d20dc6f4bd</id>
<content type='text'>
Pull timers and timekeeping updates from Thomas Gleixner:

 - Core infrastucture work for Y2038 to address the COMPAT interfaces:

     + Add a new Y2038 safe __kernel_timespec and use it in the core
       code

     + Introduce config switches which allow to control the various
       compat mechanisms

     + Use the new config switch in the posix timer code to control the
       32bit compat syscall implementation.

 - Prevent bogus selection of CPU local clocksources which causes an
   endless reselection loop

 - Remove the extra kthread in the clocksource code which has no value
   and just adds another level of indirection

 - The usual bunch of trivial updates, cleanups and fixlets all over the
   place

 - More SPDX conversions

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  clocksource/drivers/mxs_timer: Switch to SPDX identifier
  clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Remove outdated file path
  clocksource/drivers/arc_timer: Add comments about locking while read GFRC
  clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages
  clocksource/drivers/sprd: Fix Kconfig dependency
  clocksource: Move inline keyword to the beginning of function declarations
  timer_list: Remove unused function pointer typedef
  timers: Adjust a kernel-doc comment
  tick: Prefer a lower rating device only if it's CPU local device
  clocksource: Remove kthread
  time: Change nanosleep to safe __kernel_* types
  time: Change types to new y2038 safe __kernel_* types
  time: Fix get_timespec64() for y2038 safe compat interfaces
  time: Add new y2038 safe __kernel_timespec
  posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_64BIT_TIME in architectures
  compat: Enable compat_get/put_timespec64 always
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timers and timekeeping updates from Thomas Gleixner:

 - Core infrastucture work for Y2038 to address the COMPAT interfaces:

     + Add a new Y2038 safe __kernel_timespec and use it in the core
       code

     + Introduce config switches which allow to control the various
       compat mechanisms

     + Use the new config switch in the posix timer code to control the
       32bit compat syscall implementation.

 - Prevent bogus selection of CPU local clocksources which causes an
   endless reselection loop

 - Remove the extra kthread in the clocksource code which has no value
   and just adds another level of indirection

 - The usual bunch of trivial updates, cleanups and fixlets all over the
   place

 - More SPDX conversions

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  clocksource/drivers/mxs_timer: Switch to SPDX identifier
  clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Remove outdated file path
  clocksource/drivers/arc_timer: Add comments about locking while read GFRC
  clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages
  clocksource/drivers/sprd: Fix Kconfig dependency
  clocksource: Move inline keyword to the beginning of function declarations
  timer_list: Remove unused function pointer typedef
  timers: Adjust a kernel-doc comment
  tick: Prefer a lower rating device only if it's CPU local device
  clocksource: Remove kthread
  time: Change nanosleep to safe __kernel_* types
  time: Change types to new y2038 safe __kernel_* types
  time: Fix get_timespec64() for y2038 safe compat interfaces
  time: Add new y2038 safe __kernel_timespec
  posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_64BIT_TIME in architectures
  compat: Enable compat_get/put_timespec64 always
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>proc: introduce proc_create_seq_private</title>
<updated>2018-05-16T05:23:35+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2018-04-24T15:05:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=44414d82cfe0f68cb59d0a42f599ccd893ae0032'/>
<id>44414d82cfe0f68cb59d0a42f599ccd893ae0032</id>
<content type='text'>
Variant of proc_create_data that directly take a struct seq_operations
argument + a private state size and drastically reduces the boilerplate
code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Variant of proc_create_data that directly take a struct seq_operations
argument + a private state size and drastically reduces the boilerplate
code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>timer_list: Remove unused function pointer typedef</title>
<updated>2018-05-13T13:56:01+00:00</updated>
<author>
<name>Chen Lin</name>
<email>chen45464546@163.com</email>
</author>
<published>2018-05-11T15:47:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ed772ec873cb0d378c0329d266ae656ec1f2b511'/>
<id>ed772ec873cb0d378c0329d266ae656ec1f2b511</id>
<content type='text'>
Remove the 'printf_fn_t' typedef as it is not used.

Signed-off-by: Chen Lin &lt;chen45464546@163.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: sboyd@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/1526053649-24229-1-git-send-email-chen45464546@163.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove the 'printf_fn_t' typedef as it is not used.

Signed-off-by: Chen Lin &lt;chen45464546@163.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: sboyd@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/1526053649-24229-1-git-send-email-chen45464546@163.com
</pre>
</div>
</content>
</entry>
<entry>
<title>timer/debug: Change /proc/timer_list from 0444 to 0400</title>
<updated>2017-11-13T15:04:06+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-11-13T06:15:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8e7df2b5b7f245c9bd11064712db5cb69044a362'/>
<id>8e7df2b5b7f245c9bd11064712db5cb69044a362</id>
<content type='text'>
While it uses %pK, there's still few reasons to read this file
as non-root.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While it uses %pK, there's still few reasons to read this file
as non-root.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sysrq: Reset the watchdog timers while displaying high-resolution timers</title>
<updated>2017-03-23T19:46:53+00:00</updated>
<author>
<name>Tom Hromatka</name>
<email>tom.hromatka@oracle.com</email>
</author>
<published>2017-01-04T22:28:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0107042768658fea9f5f5a9c00b1c90f5dab6a06'/>
<id>0107042768658fea9f5f5a9c00b1c90f5dab6a06</id>
<content type='text'>
On systems with a large number of CPUs, running sysrq-&lt;q&gt; can cause
watchdog timeouts.  There are two slow sections of code in the sysrq-&lt;q&gt;
path in timer_list.c.

1. print_active_timers() - This function is called by print_cpu() and
   contains a slow goto loop.  On a machine with hundreds of CPUs, this
   loop took approximately 100ms for the first CPU in a NUMA node.
   (Subsequent CPUs in the same node ran much quicker.)  The total time
   to print all of the CPUs is ultimately long enough to trigger the
   soft lockup watchdog.

2. print_tickdevice() - This function outputs a large amount of textual
   information.  This function also took approximately 100ms per CPU.

Since sysrq-&lt;q&gt; is not a performance critical path, there should be no
harm in touching the nmi watchdog in both slow sections above.  Touching
it in just one location was insufficient on systems with hundreds of
CPUs as occasional timeouts were still observed during testing.

This issue was observed on an Oracle T7 machine with 128 CPUs, but I
anticipate it may affect other systems with similarly large numbers of
CPUs.

Signed-off-by: Tom Hromatka &lt;tom.hromatka@oracle.com&gt;
Reviewed-by: Rob Gardner &lt;rob.gardner@oracle.com&gt;
Signed-off-by: John Stultz &lt;john.stultz@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On systems with a large number of CPUs, running sysrq-&lt;q&gt; can cause
watchdog timeouts.  There are two slow sections of code in the sysrq-&lt;q&gt;
path in timer_list.c.

1. print_active_timers() - This function is called by print_cpu() and
   contains a slow goto loop.  On a machine with hundreds of CPUs, this
   loop took approximately 100ms for the first CPU in a NUMA node.
   (Subsequent CPUs in the same node ran much quicker.)  The total time
   to print all of the CPUs is ultimately long enough to trigger the
   soft lockup watchdog.

2. print_tickdevice() - This function outputs a large amount of textual
   information.  This function also took approximately 100ms per CPU.

Since sysrq-&lt;q&gt; is not a performance critical path, there should be no
harm in touching the nmi watchdog in both slow sections above.  Touching
it in just one location was insufficient on systems with hundreds of
CPUs as occasional timeouts were still observed during testing.

This issue was observed on an Oracle T7 machine with 128 CPUs, but I
anticipate it may affect other systems with similarly large numbers of
CPUs.

Signed-off-by: Tom Hromatka &lt;tom.hromatka@oracle.com&gt;
Reviewed-by: Rob Gardner &lt;rob.gardner@oracle.com&gt;
Signed-off-by: John Stultz &lt;john.stultz@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>timer_list: Remove useless cast when printing</title>
<updated>2017-02-10T10:15:08+00:00</updated>
<author>
<name>Mars Cheng</name>
<email>mars.cheng@mediatek.com</email>
</author>
<published>2017-02-09T07:50:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7551b02b94ad1daee3a79d667dc3c46d08328f87'/>
<id>7551b02b94ad1daee3a79d667dc3c46d08328f87</id>
<content type='text'>
hrtimer_resolution is already unsigned int, not necessary to cast
it when printing.

Signed-off-by: Mars Cheng &lt;mars.cheng@mediatek.com&gt;
Cc: CC Hwang &lt;cc.hwang@mediatek.com&gt;
Cc: wsd_upstream@mediatek.com
Cc: Loda Chou &lt;loda.chou@mediatek.com&gt;
Cc: Jades Shih &lt;jades.shih@mediatek.com&gt;
Cc: Miles Chen &lt;miles.chen@mediatek.com&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: My Chuang &lt;my.chuang@mediatek.com&gt;
Cc: Matthias Brugger &lt;matthias.bgg@gmail.com&gt;
Cc: Yingjoe Chen &lt;yingjoe.chen@mediatek.com&gt;
Link: http://lkml.kernel.org/r/1486626615-5879-1-git-send-email-mars.cheng@mediatek.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
hrtimer_resolution is already unsigned int, not necessary to cast
it when printing.

Signed-off-by: Mars Cheng &lt;mars.cheng@mediatek.com&gt;
Cc: CC Hwang &lt;cc.hwang@mediatek.com&gt;
Cc: wsd_upstream@mediatek.com
Cc: Loda Chou &lt;loda.chou@mediatek.com&gt;
Cc: Jades Shih &lt;jades.shih@mediatek.com&gt;
Cc: Miles Chen &lt;miles.chen@mediatek.com&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: My Chuang &lt;my.chuang@mediatek.com&gt;
Cc: Matthias Brugger &lt;matthias.bgg@gmail.com&gt;
Cc: Yingjoe Chen &lt;yingjoe.chen@mediatek.com&gt;
Link: http://lkml.kernel.org/r/1486626615-5879-1-git-send-email-mars.cheng@mediatek.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</pre>
</div>
</content>
</entry>
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