<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/Documentation/RCU, branch v3.12</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branches 'doc.2013.08.19a', 'fixes.2013.08.20a', 'sysidle.2013.08.31a' and 'torture.2013.08.20a' into HEAD</title>
<updated>2013-08-31T21:44:45+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-08-31T21:44:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25f27ce4a6a4995c8bdd69b4b2180465ed5ad2b8'/>
<id>25f27ce4a6a4995c8bdd69b4b2180465ed5ad2b8</id>
<content type='text'>
doc.2013.08.19a: Documentation updates
fixes.2013.08.20a: Miscellaneous fixes
sysidle.2013.08.31a: Detect system-wide idle state.
torture.2013.08.20a: rcutorture updates.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
doc.2013.08.19a: Documentation updates
fixes.2013.08.20a: Miscellaneous fixes
sysidle.2013.08.31a: Detect system-wide idle state.
torture.2013.08.20a: rcutorture updates.
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: Increase rcutorture test coverage</title>
<updated>2013-08-20T18:38:41+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-06-12T22:12:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2ec1f2d98752293f4831ce7d7bdbc3fc36bdd114'/>
<id>2ec1f2d98752293f4831ce7d7bdbc3fc36bdd114</id>
<content type='text'>
Currently, rcutorture has separate torture_types to test synchronous,
asynchronous, and expedited grace-period primitives.  This has
two disadvantages: (1) Three times the number of runs to cover the
combinations and (2) Little testing of concurrent combinations of the
three options.  This commit therefore adds a pair of module parameters
that control normal and expedited state, with the default being both
types, randomly selected, by the fakewriter processes, thus reducing
source-code size and increasing test coverage.  In addtion, the writer
task switches between asynchronous-normal and expedited grace-period
primitives driven by the same pair of module parameters.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, rcutorture has separate torture_types to test synchronous,
asynchronous, and expedited grace-period primitives.  This has
two disadvantages: (1) Three times the number of runs to cover the
combinations and (2) Little testing of concurrent combinations of the
three options.  This commit therefore adds a pair of module parameters
that control normal and expedited state, with the default being both
types, randomly selected, by the fakewriter processes, thus reducing
source-code size and increasing test coverage.  In addtion, the writer
task switches between asynchronous-normal and expedited grace-period
primitives driven by the same pair of module parameters.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: Update RTFP documentation</title>
<updated>2013-08-20T04:39:27+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-05-01T17:05:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6ae3771850910018c89b4ce063c52008bf2c8d6a'/>
<id>6ae3771850910018c89b4ce063c52008bf2c8d6a</id>
<content type='text'>
Note that this commit also updates the formatting of serveral of the
bibtex entries to conform to that of my .bib files.  I started
accumulating entries back in the 1980s, back when bibtex insisted
that comma (",") was a separator, not a terminator.  This rule forced
commas to the fronts of lines.  25 years later, bibtex allows commas
to be terminators, but I am too lazy to rework all my .bib files.
Keeping the same format as my .bib files allows my to simply
incorporate my RCU.bib file into Documentation/RCU/RTFP.txt, which
is much easier than my earlier practice of keeping track of what
had changed and adding individual entries.  (I sometimes find relevant
papers that were published some years back, for example.)

In addition, this change adds entries for papers published in the
last year or so.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Note that this commit also updates the formatting of serveral of the
bibtex entries to conform to that of my .bib files.  I started
accumulating entries back in the 1980s, back when bibtex insisted
that comma (",") was a separator, not a terminator.  This rule forced
commas to the fronts of lines.  25 years later, bibtex allows commas
to be terminators, but I am too lazy to rework all my .bib files.
Keeping the same format as my .bib files allows my to simply
incorporate my RCU.bib file into Documentation/RCU/RTFP.txt, which
is much easier than my earlier practice of keeping track of what
had changed and adding individual entries.  (I sometimes find relevant
papers that were published some years back, for example.)

In addition, this change adds entries for papers published in the
last year or so.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: Fix rcu_barrier() documentation</title>
<updated>2013-08-19T00:05:32+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-04-18T21:25:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d84297c99bd9f63baf92c9f2d36582f879858664'/>
<id>d84297c99bd9f63baf92c9f2d36582f879858664</id>
<content type='text'>
There was a time when rcu_barrier() was guaranteed to wait for at least
a grace period, but that time ended due to energy-efficiency concerns.
So now rcu_barrier() is a no-op if there are no RCU callbacks queued in
the system.  This commit updates the documentation to reflect this change.

Now, rcu_barrier() often does wait for a grace period, so, one could
imagine some modification to rcu_barrier() to more efficiently handle
cases where both rcu_barrier() and a grace period are needed.  But this
must wait until someone shows a real-world need for a change.

Reported-by: Bob Copeland &lt;bob@cozybit.com&gt;
Reported-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There was a time when rcu_barrier() was guaranteed to wait for at least
a grace period, but that time ended due to energy-efficiency concerns.
So now rcu_barrier() is a no-op if there are no RCU callbacks queued in
the system.  This commit updates the documentation to reflect this change.

Now, rcu_barrier() often does wait for a grace period, so, one could
imagine some modification to rcu_barrier() to more efficiently handle
cases where both rcu_barrier() and a grace period are needed.  But this
must wait until someone shows a real-world need for a change.

Reported-by: Bob Copeland &lt;bob@cozybit.com&gt;
Reported-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD</title>
<updated>2013-06-10T20:46:44+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-06-10T20:46:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=be77f87c001b770f13fe742becb08b847d9542f1'/>
<id>be77f87c001b770f13fe742becb08b847d9542f1</id>
<content type='text'>
cbnum.2013.06.10a: Apply simplifications stemming from the new callback
	numbering.

doc.2013.06.10a: Documentation updates.

fixes.2013.06.10a: Miscellaneous fixes.

srcu.2013.06.10a: Updates to SRCU.

tiny.2013.06.10a: Eliminate TINY_PREEMPT_RCU.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
cbnum.2013.06.10a: Apply simplifications stemming from the new callback
	numbering.

doc.2013.06.10a: Documentation updates.

fixes.2013.06.10a: Miscellaneous fixes.

srcu.2013.06.10a: Updates to SRCU.

tiny.2013.06.10a: Eliminate TINY_PREEMPT_RCU.
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: Remove TINY_PREEMPT_RCU tracing documentation</title>
<updated>2013-06-10T20:45:52+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-03-27T18:32:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7807acdb6b794b3af42dfa1912edd4fba8d0b622'/>
<id>7807acdb6b794b3af42dfa1912edd4fba8d0b622</id>
<content type='text'>
Because TINY_PREEMPT_RCU is no more, this commit removes its tracing
formats from the documentation.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Because TINY_PREEMPT_RCU is no more, this commit removes its tracing
formats from the documentation.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw().</title>
<updated>2013-06-10T20:45:25+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-03-12T23:54:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=99f88919f8fa8a8b01b5306c59c9977b94604df8'/>
<id>99f88919f8fa8a8b01b5306c59c9977b94604df8</id>
<content type='text'>
These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Lai Jiangshan &lt;laijs@cn.fujitsu.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Lai Jiangshan &lt;laijs@cn.fujitsu.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge commit '8700c95adb03' into timers/nohz</title>
<updated>2013-05-02T15:54:19+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2013-05-02T15:37:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c032862fba51a3ca504752d3a25186b324c5ce83'/>
<id>c032862fba51a3ca504752d3a25186b324c5ce83</id>
<content type='text'>
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has these
updates.

Conflicts:
	include/linux/perf_event.h
	kernel/rcutree.h
	kernel/rcutree_plugin.h

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has these
updates.

Conflicts:
	include/linux/perf_event.h
	kernel/rcutree.h
	kernel/rcutree_plugin.h

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON</title>
<updated>2013-04-03T11:56:03+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2011-08-10T21:21:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3451d0243c3cdfd729b36f9684a14659d4895ca3'/>
<id>3451d0243c3cdfd729b36f9684a14659d4895ca3</id>
<content type='text'>
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.

As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.

It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.

On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.

But we can't afford both at the same time or we run into
a circular dependency:

1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
   CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE

We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.

So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.

Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Geoff Levand &lt;geoff@infradead.org&gt;
Cc: Gilad Ben Yossef &lt;gilad@benyossef.com&gt;
Cc: Hakan Akkan &lt;hakanakkan@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Kevin Hilman &lt;khilman@linaro.org&gt;
Cc: Li Zhong &lt;zhong@linux.vnet.ibm.com&gt;
Cc: Namhyung Kim &lt;namhyung.kim@lge.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.

As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.

It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.

On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.

But we can't afford both at the same time or we run into
a circular dependency:

1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
   CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE

We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.

So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.

Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Geoff Levand &lt;geoff@infradead.org&gt;
Cc: Gilad Ben Yossef &lt;gilad@benyossef.com&gt;
Cc: Hakan Akkan &lt;hakanakkan@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Kevin Hilman &lt;khilman@linaro.org&gt;
Cc: Li Zhong &lt;zhong@linux.vnet.ibm.com&gt;
Cc: Namhyung Kim &lt;namhyung.kim@lge.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'doc.2013.03.12a', 'fixes.2013.03.13a' and 'idlenocb.2013.03.26b' into HEAD</title>
<updated>2013-03-26T15:07:38+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.vnet.ibm.com</email>
</author>
<published>2013-03-26T15:07:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6d87669357936bffa1e8fea7a4e7743e76905736'/>
<id>6d87669357936bffa1e8fea7a4e7743e76905736</id>
<content type='text'>
doc.2013.03.12a: Documentation changes.

fixes.2013.03.13a: Miscellaneous fixes.

idlenocb.2013.03.26b: Remove restrictions on no-CBs CPUs, make
	RCU_FAST_NO_HZ take advantage of numbered callbacks, add
	callback acceleration based on numbered callbacks.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
doc.2013.03.12a: Documentation changes.

fixes.2013.03.13a: Miscellaneous fixes.

idlenocb.2013.03.26b: Remove restrictions on no-CBs CPUs, make
	RCU_FAST_NO_HZ take advantage of numbered callbacks, add
	callback acceleration based on numbered callbacks.
</pre>
</div>
</content>
</entry>
</feed>
