<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/interrupt.h, branch v3.4.67</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.4.67</id>
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<updated>2012-03-28T17:30:03Z</updated>
<entry>
<title>Remove all #inclusions of asm/system.h</title>
<updated>2012-03-28T17:30:03Z</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2012-03-28T17:30:03Z</published>
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<id>urn:sha1:9ffc93f203c18a70623f21950f1dd473c9ec48cd</id>
<content type='text'>
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*&lt;asm/system[.]h&gt;.*\n!!' `grep -Irl '^#\s*include\s*&lt;asm/system[.]h&gt;' *`

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
</entry>
<entry>
<title>tracing/softirq: Move __raise_softirq_irqoff() out of header</title>
<updated>2012-02-03T14:48:19Z</updated>
<author>
<name>Steven Rostedt</name>
<email>srostedt@redhat.com</email>
</author>
<published>2012-01-26T01:18:55Z</published>
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<id>urn:sha1:f069686e4bdc60a637d210ea3eea25fcdb82df88</id>
<content type='text'>
The __raise_softirq_irqoff() contains a tracepoint. As tracepoints in headers
can cause issues, and not to mention, bloats the kernel when they are
in a static inline, it is best to move the function that contains the
tracepoint out of the header and into softirq.c.

Link: http://lkml.kernel.org/r/20120118120711.GB14863@elte.hu

Suggested-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier</title>
<updated>2011-10-17T09:42:49Z</updated>
<author>
<name>Ian Campbell</name>
<email>ian.campbell@citrix.com</email>
</author>
<published>2011-10-03T14:37:00Z</published>
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<id>urn:sha1:9bab0b7fbaceec47d32db51cd9e59c82fb071f5a</id>
<content type='text'>
This adds a mechanism to resume selected IRQs during syscore_resume
instead of dpm_resume_noirq.

Under Xen we need to resume IRQs associated with IPIs early enough
that the resched IPI is unmasked and we can therefore schedule
ourselves out of the stop_machine where the suspend/resume takes
place.

This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME".

Signed-off-by: Ian Campbell &lt;ian.campbell@citrix.com&gt;
Cc: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Cc: Jeremy Fitzhardinge &lt;Jeremy.Fitzhardinge@citrix.com&gt;
Cc: xen-devel &lt;xen-devel@lists.xensource.com&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk
Cc: stable@kernel.org (at least to 2.6.32.y)
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
</entry>
<entry>
<title>genirq: percpu: allow interrupt type to be set at enable time</title>
<updated>2011-10-03T13:35:27Z</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2011-09-30T09:48:47Z</published>
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<id>urn:sha1:1e7c5fd29487ee88cb3abac945bafa60ae026146</id>
<content type='text'>
As request_percpu_irq() doesn't allow for a percpu interrupt to have
its type configured (it is generally impossible to configure it on all
CPUs at once), add a 'type' argument to enable_percpu_irq().

This allows some low-level, board specific init code to be switched to
a generic API.

[ tglx: Added WARN_ON argument ]

Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Abhijeet Dharmapurikar &lt;adharmap@codeaurora.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
</entry>
<entry>
<title>genirq: Add support for per-cpu dev_id interrupts</title>
<updated>2011-10-03T13:35:26Z</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2011-09-23T16:03:06Z</published>
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<id>urn:sha1:31d9d9b6d83030f748d013e61502fa5477e2ac0e</id>
<content type='text'>
The ARM GIC interrupt controller offers per CPU interrupts (PPIs),
which are usually used to connect local timers to each core. Each CPU
has its own private interface to the GIC, and only sees the PPIs that
are directly connect to it.

While these timers are separate devices and have a separate interrupt
line to a core, they all use the same IRQ number.

For these devices, request_irq() is not the right API as it assumes
that an IRQ number is visible by a number of CPUs (through the
affinity setting), but makes it very awkward to express that an IRQ
number can be handled by all CPUs, and yet be a different interrupt
line on each CPU, requiring a different dev_id cookie to be passed
back to the handler.

The *_percpu_irq() functions is designed to overcome these
limitations, by providing a per-cpu dev_id vector:

int request_percpu_irq(unsigned int irq, irq_handler_t handler,
		   const char *devname, void __percpu *percpu_dev_id);
void free_percpu_irq(unsigned int, void __percpu *);
int setup_percpu_irq(unsigned int irq, struct irqaction *new);
void remove_percpu_irq(unsigned int irq, struct irqaction *act);
void enable_percpu_irq(unsigned int irq);
void disable_percpu_irq(unsigned int irq);

The API has a number of limitations:
- no interrupt sharing
- no threading
- common handler across all the CPUs

Once the interrupt is requested using setup_percpu_irq() or
request_percpu_irq(), it must be enabled by each core that wishes its
local interrupt to be delivered.

Based on an initial patch by Thomas Gleixner.

Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
</entry>
<entry>
<title>atomic: use &lt;linux/atomic.h&gt;</title>
<updated>2011-07-26T23:49:47Z</updated>
<author>
<name>Arun Sharma</name>
<email>asharma@fb.com</email>
</author>
<published>2011-07-26T23:09:06Z</published>
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<id>urn:sha1:60063497a95e716c9a689af3be2687d261f115b4</id>
<content type='text'>
This allows us to move duplicated code in &lt;asm/atomic.h&gt;
(atomic_inc_not_zero() for now) to &lt;linux/atomic.h&gt;

Signed-off-by: Arun Sharma &lt;asharma@fb.com&gt;
Reviewed-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Acked-by: Mike Frysinger &lt;vapier@gentoo.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>
</entry>
<entry>
<title>rcu: Use softirq to address performance regression</title>
<updated>2011-06-14T22:25:39Z</updated>
<author>
<name>Shaohua Li</name>
<email>shaohua.li@intel.com</email>
</author>
<published>2011-06-14T05:26:25Z</published>
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<id>urn:sha1:09223371deac67d08ca0b70bd18787920284c967</id>
<content type='text'>
Commit a26ac2455ffcf3(rcu: move TREE_RCU from softirq to kthread)
introduced performance regression. In an AIM7 test, this commit degraded
performance by about 40%.

The commit runs rcu callbacks in a kthread instead of softirq. We observed
high rate of context switch which is caused by this. Out test system has
64 CPUs and HZ is 1000, so we saw more than 64k context switch per second
which is caused by RCU's per-CPU kthread.  A trace showed that most of
the time the RCU per-CPU kthread doesn't actually handle any callbacks,
but instead just does a very small amount of work handling grace periods.
This means that RCU's per-CPU kthreads are making the scheduler do quite
a bit of work in order to allow a very small amount of RCU-related
processing to be done.

Alex Shi's analysis determined that this slowdown is due to lock
contention within the scheduler.  Unfortunately, as Peter Zijlstra points
out, the scheduler's real-time semantics require global action, which
means that this contention is inherent in real-time scheduling.  (Yes,
perhaps someone will come up with a workaround -- otherwise, -rt is not
going to do well on large SMP systems -- but this patch will work around
this issue in the meantime.  And "the meantime" might well be forever.)

This patch therefore re-introduces softirq processing to RCU, but only
for core RCU work.  RCU callbacks are still executed in kthread context,
so that only a small amount of RCU work runs in softirq context in the
common case.  This should minimize ksoftirqd execution, allowing us to
skip boosting of ksoftirqd for CONFIG_RCU_BOOST=y kernels.

Signed-off-by: Shaohua Li &lt;shaohua.li@intel.com&gt;
Tested-by: "Alex,Shi" &lt;alex.shi@intel.com&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
</content>
</entry>
<entry>
<title>rcu: move TREE_RCU from softirq to kthread</title>
<updated>2011-05-06T06:16:54Z</updated>
<author>
<name>Paul E. McKenney</name>
<email>paul.mckenney@linaro.org</email>
</author>
<published>2011-01-12T22:10:23Z</published>
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<id>urn:sha1:a26ac2455ffcf3be5c6ef92bc6df7182700f2114</id>
<content type='text'>
If RCU priority boosting is to be meaningful, callback invocation must
be boosted in addition to preempted RCU readers.  Otherwise, in presence
of CPU real-time threads, the grace period ends, but the callbacks don't
get invoked.  If the callbacks don't get invoked, the associated memory
doesn't get freed, so the system is still subject to OOM.

But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit
moves the callback invocations to a kthread, which can be boosted easily.

Also add comments and properly synchronized all accesses to
rcu_cpu_kthread_task, as suggested by Lai Jiangshan.

Signed-off-by: Paul E. McKenney &lt;paul.mckenney@linaro.org&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
</entry>
<entry>
<title>Fix common misspellings</title>
<updated>2011-03-31T14:26:23Z</updated>
<author>
<name>Lucas De Marchi</name>
<email>lucas.demarchi@profusion.mobi</email>
</author>
<published>2011-03-31T01:57:33Z</published>
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<id>urn:sha1:25985edcedea6396277003854657b5f3cb31a628</id>
<content type='text'>
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi &lt;lucas.demarchi@profusion.mobi&gt;
</content>
</entry>
<entry>
<title>genirq: Remove now obsolete set_irq_wake()</title>
<updated>2011-03-29T22:35:34Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2011-03-29T22:35:34Z</published>
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<id>urn:sha1:380a26be7d5af83f3831c3b6697031dffbb1c8f3</id>
<content type='text'>
Missed that one in the big compat remval patch

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
</entry>
</feed>
