<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/xen, branch v2.6.35-rc4</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>xen: avoid allocation causing potential swap activity on the resume path</title>
<updated>2010-06-03T08:34:45+00:00</updated>
<author>
<name>Ian Campbell</name>
<email>ian.campbell@citrix.com</email>
</author>
<published>2010-05-25T09:45:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=b3831cb55d383e8eb55d3b56c715fb48459b87c9'/>
<id>b3831cb55d383e8eb55d3b56c715fb48459b87c9</id>
<content type='text'>
Since the device we are resuming could be the device containing the
swap device we should ensure that the allocation cannot cause
IO.

On resume, this path is triggered when the running system tries to
continue using its devices.  If it cannot then the resume will fail;
to try to avoid this we let it dip into the emergency pools.

The majority of these changes were made when linux-2.6.18-xen.hg
changeset e8b49cfbdac0 was ported upstream in
a144ff09bc52ef3f3684ed23eadc9c7c0e57b3aa but somehow this hunk was
dropped.

Signed-off-by: Ian Campbell &lt;ian.campbell@citrix.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@goop.org&gt;
Cc: Stable Kernel &lt;stable@kernel.org&gt; # .32.x
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the device we are resuming could be the device containing the
swap device we should ensure that the allocation cannot cause
IO.

On resume, this path is triggered when the running system tries to
continue using its devices.  If it cannot then the resume will fail;
to try to avoid this we let it dip into the emergency pools.

The majority of these changes were made when linux-2.6.18-xen.hg
changeset e8b49cfbdac0 was ported upstream in
a144ff09bc52ef3f3684ed23eadc9c7c0e57b3aa but somehow this hunk was
dropped.

Signed-off-by: Ian Campbell &lt;ian.campbell@citrix.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@goop.org&gt;
Cc: Stable Kernel &lt;stable@kernel.org&gt; # .32.x
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: fix build when SYSRQ is disabled</title>
<updated>2010-05-25T15:07:07+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>randy.dunlap@oracle.com</email>
</author>
<published>2010-05-24T21:33:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f3bc3189a001ec85c7b1119ad4aa5e39eea0f05e'/>
<id>f3bc3189a001ec85c7b1119ad4aa5e39eea0f05e</id>
<content type='text'>
Fix build error when CONFIG_MAGIC_SYSRQ is not enabled:

drivers/xen/manage.c:223: error: implicit declaration of function 'handle_sysrq'

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@xensource.com&gt;
Cc: Chris Wright &lt;chrisw@sous-sol.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>
Fix build error when CONFIG_MAGIC_SYSRQ is not enabled:

drivers/xen/manage.c:223: error: implicit declaration of function 'handle_sysrq'

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@xensource.com&gt;
Cc: Chris Wright &lt;chrisw@sous-sol.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>stop_machine: reimplement using cpu_stop</title>
<updated>2010-05-06T16:49:20+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-05-06T16:49:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=3fc1f1e27a5b807791d72e5d992aa33b668a6626'/>
<id>3fc1f1e27a5b807791d72e5d992aa33b668a6626</id>
<content type='text'>
Reimplement stop_machine using cpu_stop.  As cpu stoppers are
guaranteed to be available for all online cpus,
stop_machine_create/destroy() are no longer necessary and removed.

With resource management and synchronization handled by cpu_stop, the
new implementation is much simpler.  Asking the cpu_stop to execute
the stop_cpu() state machine on all online cpus with cpu hotplug
disabled is enough.

stop_machine itself doesn't need to manage any global resources
anymore, so all per-instance information is rolled into struct
stop_machine_data and the mutex and all static data variables are
removed.

The previous implementation created and destroyed RT workqueues as
necessary which made stop_machine() calls highly expensive on very
large machines.  According to Dimitri Sivanich, preventing the dynamic
creation/destruction makes booting faster more than twice on very
large machines.  cpu_stop resources are preallocated for all online
cpus and should have the same effect.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Acked-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Reimplement stop_machine using cpu_stop.  As cpu stoppers are
guaranteed to be available for all online cpus,
stop_machine_create/destroy() are no longer necessary and removed.

With resource management and synchronization handled by cpu_stop, the
new implementation is much simpler.  Asking the cpu_stop to execute
the stop_cpu() state machine on all online cpus with cpu hotplug
disabled is enough.

stop_machine itself doesn't need to manage any global resources
anymore, so all per-instance information is rolled into struct
stop_machine_data and the mutex and all static data variables are
removed.

The previous implementation created and destroyed RT workqueues as
necessary which made stop_machine() calls highly expensive on very
large machines.  According to Dimitri Sivanich, preventing the dynamic
creation/destruction makes booting faster more than twice on very
large machines.  cpu_stop resources are preallocated for all online
cpus and should have the same effect.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Acked-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h</title>
<updated>2010-03-30T13:02:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-03-24T08:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>5a0e3ad6af8660be21ca98a971cd00f331318c05</id>
<content type='text'>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Driver core: Constify struct sysfs_ops in struct kobj_type</title>
<updated>2010-03-08T01:04:49+00:00</updated>
<author>
<name>Emese Revfy</name>
<email>re.emese@gmail.com</email>
</author>
<published>2010-01-19T01:58:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=52cf25d0ab7f78eeecc59ac652ed5090f69b619e'/>
<id>52cf25d0ab7f78eeecc59ac652ed5090f69b619e</id>
<content type='text'>
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy &lt;re.emese@gmail.com&gt;
Acked-by: David Teigland &lt;teigland@redhat.com&gt;
Acked-by: Matt Domsch &lt;Matt_Domsch@dell.com&gt;
Acked-by: Maciej Sosnowski &lt;maciej.sosnowski@intel.com&gt;
Acked-by: Hans J. Koch &lt;hjk@linutronix.de&gt;
Acked-by: Pekka Enberg &lt;penberg@cs.helsinki.fi&gt;
Acked-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
Acked-by: Stephen Hemminger &lt;shemminger@vyatta.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy &lt;re.emese@gmail.com&gt;
Acked-by: David Teigland &lt;teigland@redhat.com&gt;
Acked-by: Matt Domsch &lt;Matt_Domsch@dell.com&gt;
Acked-by: Maciej Sosnowski &lt;maciej.sosnowski@intel.com&gt;
Acked-by: Hans J. Koch &lt;hjk@linutronix.de&gt;
Acked-by: Pekka Enberg &lt;penberg@cs.helsinki.fi&gt;
Acked-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
Acked-by: Stephen Hemminger &lt;shemminger@vyatta.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>xen: add kconfig menu</title>
<updated>2010-03-06T19:26:46+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>randy.dunlap@oracle.com</email>
</author>
<published>2010-03-05T21:44:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=27fb7f009bdb1ff13d4e4c008a2fd36b2305055b'/>
<id>27fb7f009bdb1ff13d4e4c008a2fd36b2305055b</id>
<content type='text'>
Currently the xen support drivers are displayed in the main Device Drivers
menu of the config tools instead of in their own sub-menu, so move them to
their own sub-menu, like the rest of the driver world uses.

This keeps the main Device Drivers menu from becoming messy.

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Cc: Jeremy Fitzhardinge &lt;jeremy@xensource.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>
Currently the xen support drivers are displayed in the main Device Drivers
menu of the config tools instead of in their own sub-menu, so move them to
their own sub-menu, like the rest of the driver world uses.

This keeps the main Device Drivers menu from becoming messy.

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Cc: Jeremy Fitzhardinge &lt;jeremy@xensource.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>xen: Remove unnecessary arch specific xen irq functions.</title>
<updated>2010-02-19T01:17:58+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2010-02-18T02:49:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ca4dbc668412d5fe039be3e26e8e717a616d1ca5'/>
<id>ca4dbc668412d5fe039be3e26e8e717a616d1ca5</id>
<content type='text'>
Right now xen's use of the x86 and ia64 handle_irq is just bizarre and very
fragile as it is very non-obvious the function exists and is is used by
code out in drivers/....  Luckily using handle_irq is completely unnecessary,
and we can just use the generic irq apis instead.

This still leaves drivers/xen/events.c as a problematic user of the generic
irq apis it has "static struct irq_info irq_info[NR_IRQS]" but that can be
fixed some other time.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
LKML-Reference: &lt;4B7CAAD2.10803@kernel.org&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@goop.org&gt;
Cc: Ian Campbell &lt;Ian.Campbell@citrix.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Right now xen's use of the x86 and ia64 handle_irq is just bizarre and very
fragile as it is very non-obvious the function exists and is is used by
code out in drivers/....  Luckily using handle_irq is completely unnecessary,
and we can just use the generic irq apis instead.

This still leaves drivers/xen/events.c as a problematic user of the generic
irq apis it has "static struct irq_info irq_info[NR_IRQS]" but that can be
fixed some other time.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
LKML-Reference: &lt;4B7CAAD2.10803@kernel.org&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy@goop.org&gt;
Cc: Ian Campbell &lt;Ian.Campbell@citrix.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: fix hang on suspend.</title>
<updated>2010-01-13T10:01:35+00:00</updated>
<author>
<name>Ian Campbell</name>
<email>ian.campbell@citrix.com</email>
</author>
<published>2009-12-17T13:57:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=c5cae661d6cf808b6984762f763261adf35f3eb7'/>
<id>c5cae661d6cf808b6984762f763261adf35f3eb7</id>
<content type='text'>
In 65f63384 "xen: improve error handling in do_suspend" I said:
    - xs_suspend()/xs_resume() and dpm_suspend_noirq()/dpm_resume_noirq() were not
      nested in the obvious way.
and changed the ordering of the calls as so:
    BEFORE		AFTER
    xs_suspend		dpm_suspend_noirq
    dpm_suspend_noirq	xs_suspend
    *SUSPEND*		*SUSPEND*
    dpm_resume_noirq	dpm_resume_noirq
    xs_resume		xs_resume
Clearly this is not an improvement and I was talking rubbish.

In particular the new ordering is susceptible to a hang if a xenstore write is
in progress at the point at which the suspend kicks in. When the suspend
process calls xs_suspend it tries to take the request_mutex but if a write is
in progress it could be looping in xenbus_xs.c:read_reply() waiting for
something to arrive on &amp;xs_state.reply_list while holding the request_mutex
(taken in the caller of read_reply).

However if we have done dpm_suspend_noirq before xs_suspend then we won't get
any more xenstore interrupts and process_msg() will never be woken up to add
anything to the reply_list.

Fix this by calling xs_suspend before dpm_suspend_noirq. If dpm_suspend_noirq
fails then make sure we go through the xs_suspend_cancel() code path.

Signed-off-by: Ian Campbell &lt;ian.campbell@citrix.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy.fitzhardinge@citrix.com&gt;
Cc: Stable Kernel &lt;stable@kernel.org&gt;
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In 65f63384 "xen: improve error handling in do_suspend" I said:
    - xs_suspend()/xs_resume() and dpm_suspend_noirq()/dpm_resume_noirq() were not
      nested in the obvious way.
and changed the ordering of the calls as so:
    BEFORE		AFTER
    xs_suspend		dpm_suspend_noirq
    dpm_suspend_noirq	xs_suspend
    *SUSPEND*		*SUSPEND*
    dpm_resume_noirq	dpm_resume_noirq
    xs_resume		xs_resume
Clearly this is not an improvement and I was talking rubbish.

In particular the new ordering is susceptible to a hang if a xenstore write is
in progress at the point at which the suspend kicks in. When the suspend
process calls xs_suspend it tries to take the request_mutex but if a write is
in progress it could be looping in xenbus_xs.c:read_reply() waiting for
something to arrive on &amp;xs_state.reply_list while holding the request_mutex
(taken in the caller of read_reply).

However if we have done dpm_suspend_noirq before xs_suspend then we won't get
any more xenstore interrupts and process_msg() will never be woken up to add
anything to the reply_list.

Fix this by calling xs_suspend before dpm_suspend_noirq. If dpm_suspend_noirq
fails then make sure we go through the xs_suspend_cancel() code path.

Signed-off-by: Ian Campbell &lt;ian.campbell@citrix.com&gt;
Acked-by: Jeremy Fitzhardinge &lt;jeremy.fitzhardinge@citrix.com&gt;
Cc: Stable Kernel &lt;stable@kernel.org&gt;
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</entry>
<entry>
<title>Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6</title>
<updated>2009-12-11T20:18:16+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-12-11T20:18:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=11bd04f6f35621193311c32e0721142b073a7794'/>
<id>11bd04f6f35621193311c32e0721142b073a7794</id>
<content type='text'>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (109 commits)
  PCI: fix coding style issue in pci_save_state()
  PCI: add pci_request_acs
  PCI: fix BUG_ON triggered by logical PCIe root port removal
  PCI: remove ifdefed pci_cleanup_aer_correct_error_status
  PCI: unconditionally clear AER uncorr status register during cleanup
  x86/PCI: claim SR-IOV BARs in pcibios_allocate_resource
  PCI: portdrv: remove redundant definitions
  PCI: portdrv: remove unnecessary struct pcie_port_data
  PCI: portdrv: minor cleanup for pcie_port_device_register
  PCI: portdrv: add missing irq cleanup
  PCI: portdrv: enable device before irq initialization
  PCI: portdrv: cleanup service irqs initialization
  PCI: portdrv: check capabilities first
  PCI: portdrv: move PME capability check
  PCI: portdrv: remove redundant pcie type calculation
  PCI: portdrv: cleanup pcie_device registration
  PCI: portdrv: remove redundant pcie_port_device_probe
  PCI: Always set prefetchable base/limit upper32 registers
  PCI: read-modify-write the pcie device control register when initiating pcie flr
  PCI: show dma_mask bits in /sys
  ...

Fixed up conflicts in:
	arch/x86/kernel/amd_iommu_init.c
	drivers/pci/dmar.c
	drivers/pci/hotplug/acpiphp_glue.c
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* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (109 commits)
  PCI: fix coding style issue in pci_save_state()
  PCI: add pci_request_acs
  PCI: fix BUG_ON triggered by logical PCIe root port removal
  PCI: remove ifdefed pci_cleanup_aer_correct_error_status
  PCI: unconditionally clear AER uncorr status register during cleanup
  x86/PCI: claim SR-IOV BARs in pcibios_allocate_resource
  PCI: portdrv: remove redundant definitions
  PCI: portdrv: remove unnecessary struct pcie_port_data
  PCI: portdrv: minor cleanup for pcie_port_device_register
  PCI: portdrv: add missing irq cleanup
  PCI: portdrv: enable device before irq initialization
  PCI: portdrv: cleanup service irqs initialization
  PCI: portdrv: check capabilities first
  PCI: portdrv: move PME capability check
  PCI: portdrv: remove redundant pcie type calculation
  PCI: portdrv: cleanup pcie_device registration
  PCI: portdrv: remove redundant pcie_port_device_probe
  PCI: Always set prefetchable base/limit upper32 registers
  PCI: read-modify-write the pcie device control register when initiating pcie flr
  PCI: show dma_mask bits in /sys
  ...

Fixed up conflicts in:
	arch/x86/kernel/amd_iommu_init.c
	drivers/pci/dmar.c
	drivers/pci/hotplug/acpiphp_glue.c
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen</title>
<updated>2009-12-10T17:35:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-12-10T17:35:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ab1831b0b87851c874a75e4b3a8538e3d76b37d7'/>
<id>ab1831b0b87851c874a75e4b3a8538e3d76b37d7</id>
<content type='text'>
* 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: try harder to balloon up under memory pressure.
  Xen balloon: fix totalram_pages counting.
  xen: explicitly create/destroy stop_machine workqueues outside suspend/resume region.
  xen: improve error handling in do_suspend.
  xen: don't leak IRQs over suspend/resume.
  xen: call clock resume notifier on all CPUs
  xen: use iret for return from 64b kernel to 32b usermode
  xen: don't call dpm_resume_noirq() with interrupts disabled.
  xen: register runstate info for boot CPU early
  xen: register runstate on secondary CPUs
  xen: register timer interrupt with IRQF_TIMER
  xen: correctly restore pfn_to_mfn_list_list after resume
  xen: restore runstate_info even if !have_vcpu_info_placement
  xen: re-register runstate area earlier on resume.
  xen: wait up to 5 minutes for device connetion
  xen: improvement to wait_for_devices()
  xen: fix is_disconnected_device/exists_disconnected_device
  xen/xenbus: make DEVICE_ATTR()s static
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<pre>
* 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: try harder to balloon up under memory pressure.
  Xen balloon: fix totalram_pages counting.
  xen: explicitly create/destroy stop_machine workqueues outside suspend/resume region.
  xen: improve error handling in do_suspend.
  xen: don't leak IRQs over suspend/resume.
  xen: call clock resume notifier on all CPUs
  xen: use iret for return from 64b kernel to 32b usermode
  xen: don't call dpm_resume_noirq() with interrupts disabled.
  xen: register runstate info for boot CPU early
  xen: register runstate on secondary CPUs
  xen: register timer interrupt with IRQF_TIMER
  xen: correctly restore pfn_to_mfn_list_list after resume
  xen: restore runstate_info even if !have_vcpu_info_placement
  xen: re-register runstate area earlier on resume.
  xen: wait up to 5 minutes for device connetion
  xen: improvement to wait_for_devices()
  xen: fix is_disconnected_device/exists_disconnected_device
  xen/xenbus: make DEVICE_ATTR()s static
</pre>
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</entry>
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