<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/spinlock.c, branch v2.6.23.12</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>lockstat: hook into spinlock_t, rwlock_t, rwsem and mutex</title>
<updated>2007-07-19T17:04:49+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2007-07-19T08:48:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4fe87745a6722d42ff27a60768c77958fa1fc498'/>
<id>4fe87745a6722d42ff27a60768c77958fa1fc498</id>
<content type='text'>
Call the new lockstat tracking functions from the various lock primitives.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Jason Baron &lt;jbaron@redhat.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>
Call the new lockstat tracking functions from the various lock primitives.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Jason Baron &lt;jbaron@redhat.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>lockdep: sanitise CONFIG_PROVE_LOCKING</title>
<updated>2007-07-19T17:04:49+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2007-07-19T08:48:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ca58abcb4a6d52ee2db1b1130cea3ca2a76677b9'/>
<id>ca58abcb4a6d52ee2db1b1130cea3ca2a76677b9</id>
<content type='text'>
Ensure that all of the lock dependency tracking code is under
CONFIG_PROVE_LOCKING.  This allows us to use the held lock tracking code for
other purposes.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Jason Baron &lt;jbaron@redhat.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>
Ensure that all of the lock dependency tracking code is under
CONFIG_PROVE_LOCKING.  This allows us to use the held lock tracking code for
other purposes.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Jason Baron &lt;jbaron@redhat.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>[PATCH] lockdep: spin_lock_irqsave_nested()</title>
<updated>2006-11-25T21:28:34+00:00</updated>
<author>
<name>Arjan van de Ven</name>
<email>arjan@linux.intel.com</email>
</author>
<published>2006-11-25T19:09:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cfd3ef2346f924d6c0e82236c20fdb3a8840136a'/>
<id>cfd3ef2346f924d6c0e82236c20fdb3a8840136a</id>
<content type='text'>
Introduce spin_lock_irqsave_nested(); implementation from:
 http://lkml.org/lkml/2006/6/1/122
Patch from:
 http://lkml.org/lkml/2006/9/13/258

[akpm@osdl.org: two compile fixes]
Signed-off-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Signed-off-by: Jiri Kosina &lt;jikos@jikos.cz&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce spin_lock_irqsave_nested(); implementation from:
 http://lkml.org/lkml/2006/6/1/122
Patch from:
 http://lkml.org/lkml/2006/9/13/258

[akpm@osdl.org: two compile fixes]
Signed-off-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Signed-off-by: Jiri Kosina &lt;jikos@jikos.cz&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] Directed yield: cpu_relax variants for spinlocks and rw-locks</title>
<updated>2006-10-01T07:39:21+00:00</updated>
<author>
<name>Martin Schwidefsky</name>
<email>schwidefsky@de.ibm.com</email>
</author>
<published>2006-10-01T06:27:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ef6edc9746dc2bfdacf44eefd5f881179971c478'/>
<id>ef6edc9746dc2bfdacf44eefd5f881179971c478</id>
<content type='text'>
On systems running with virtual cpus there is optimization potential in
regard to spinlocks and rw-locks.  If the virtual cpu that has taken a lock
is known to a cpu that wants to acquire the same lock it is beneficial to
yield the timeslice of the virtual cpu in favour of the cpu that has the
lock (directed yield).

With CONFIG_PREEMPT="n" this can be implemented by the architecture without
common code changes.  Powerpc already does this.

With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
_raw_read_trylock and _raw_write_trylock in kernel/spinlock.c.  If the lock
could not be taken cpu_relax is called.  A directed yield is not possible
because cpu_relax doesn't know anything about the lock.  To be able to
yield the lock in favour of the current lock holder variants of cpu_relax
for spinlocks and rw-locks are needed.  The new _raw_spin_relax,
_raw_read_relax and _raw_write_relax primitives differ from cpu_relax
insofar that they have an argument: a pointer to the lock structure.

Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@atmel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On systems running with virtual cpus there is optimization potential in
regard to spinlocks and rw-locks.  If the virtual cpu that has taken a lock
is known to a cpu that wants to acquire the same lock it is beneficial to
yield the timeslice of the virtual cpu in favour of the cpu that has the
lock (directed yield).

With CONFIG_PREEMPT="n" this can be implemented by the architecture without
common code changes.  Powerpc already does this.

With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
_raw_read_trylock and _raw_write_trylock in kernel/spinlock.c.  If the lock
could not be taken cpu_relax is called.  A directed yield is not possible
because cpu_relax doesn't know anything about the lock.  To be able to
yield the lock in favour of the current lock holder variants of cpu_relax
for spinlocks and rw-locks are needed.  The new _raw_spin_relax,
_raw_read_relax and _raw_write_relax primitives differ from cpu_relax
insofar that they have an argument: a pointer to the lock structure.

Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@atmel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] remove generic__raw_read_trylock()</title>
<updated>2006-09-29T16:18:03+00:00</updated>
<author>
<name>Matthew Wilcox</name>
<email>matthew@wil.cx</email>
</author>
<published>2006-09-29T08:58:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=910067d188d56d80801b71b0ca1f73aa400c7b8c'/>
<id>910067d188d56d80801b71b0ca1f73aa400c7b8c</id>
<content type='text'>
If the cpu has the lock held for write, is interrupted, and the interrupt
handler calls read_trylock(), it's an instant deadlock.

Now, Dave Miller has subsequently pointed out that we don't have any
situations where this can occur.  Nevertheless, we should delete
generic__raw_read_lock (and its associated EXPORT to make Arjan happy) so that
nobody thinks they can use it.

Acked-by: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the cpu has the lock held for write, is interrupted, and the interrupt
handler calls read_trylock(), it's an instant deadlock.

Now, Dave Miller has subsequently pointed out that we don't have any
situations where this can occur.  Nevertheless, we should delete
generic__raw_read_lock (and its associated EXPORT to make Arjan happy) so that
nobody thinks they can use it.

Acked-by: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] i386: Account spinlocks to the caller during profiling for !FP kernels</title>
<updated>2006-09-26T08:52:28+00:00</updated>
<author>
<name>Andi Kleen</name>
<email>ak@suse.de</email>
</author>
<published>2006-09-26T08:52:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0cb91a2293648507886563ccb91979cfc94d6a4b'/>
<id>0cb91a2293648507886563ccb91979cfc94d6a4b</id>
<content type='text'>
This ports the algorithm from x86-64 (with improvements) to i386.
Previously this only worked for frame pointer enabled kernels.
But spinlocks have a very simple stack frame that can be manually
analyzed. Do this.

Signed-off-by: Andi Kleen &lt;ak@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This ports the algorithm from x86-64 (with improvements) to i386.
Previously this only worked for frame pointer enabled kernels.
But spinlocks have a very simple stack frame that can be manually
analyzed. Do this.

Signed-off-by: Andi Kleen &lt;ak@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] lockdep ifdef fix</title>
<updated>2006-09-06T18:00:01+00:00</updated>
<author>
<name>Jarek Poplawski</name>
<email>jarkao2@o2.pl</email>
</author>
<published>2006-09-06T07:03:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fc47e7b592dc45b03c27b0a4c8f2d215dae9944d'/>
<id>fc47e7b592dc45b03c27b0a4c8f2d215dae9944d</id>
<content type='text'>
With

	CONFIG_SMP=y
	CONFIG_PREEMPT=y
	CONFIG_LOCKDEP=y
	CONFIG_DEBUG_LOCK_ALLOC=y
	# CONFIG_PROVE_LOCKING is not set

spin_unlock_irqrestore() goes through lockdep but spin_lock_irqsave() doesn't.
Apparently, bad things happen.

Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With

	CONFIG_SMP=y
	CONFIG_PREEMPT=y
	CONFIG_LOCKDEP=y
	CONFIG_DEBUG_LOCK_ALLOC=y
	# CONFIG_PROVE_LOCKING is not set

spin_unlock_irqrestore() goes through lockdep but spin_lock_irqsave() doesn't.
Apparently, bad things happen.

Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] lockdep: prove spinlock rwlock locking correctness</title>
<updated>2006-07-03T22:27:04+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2006-07-03T07:24:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8a25d5debff2daee280e83e09d8c25d67c26a972'/>
<id>8a25d5debff2daee280e83e09d8c25d67c26a972</id>
<content type='text'>
Use the lock validator framework to prove spinlock and rwlock locking
correctness.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the lock validator framework to prove spinlock and rwlock locking
correctness.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Remove obsolete #include &lt;linux/config.h&gt;</title>
<updated>2006-06-30T17:25:36+00:00</updated>
<author>
<name>Jörn Engel</name>
<email>joern@wohnheim.fh-wedel.de</email>
</author>
<published>2006-06-30T17:25:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6ab3d5624e172c553004ecc862bfeac16d9d68b7'/>
<id>6ab3d5624e172c553004ecc862bfeac16d9d68b7</id>
<content type='text'>
Signed-off-by: Jörn Engel &lt;joern@wohnheim.fh-wedel.de&gt;
Signed-off-by: Adrian Bunk &lt;bunk@stusta.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Jörn Engel &lt;joern@wohnheim.fh-wedel.de&gt;
Signed-off-by: Adrian Bunk &lt;bunk@stusta.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] BUILD_LOCK_OPS: cleanup preempt_disable() usage</title>
<updated>2006-03-23T15:38:16+00:00</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@tv-sign.ru</email>
</author>
<published>2006-03-23T11:00:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ee25e96fcd78837c9f192aa655ce12a88bfd63d4'/>
<id>ee25e96fcd78837c9f192aa655ce12a88bfd63d4</id>
<content type='text'>
This patch changes the code from:

	preempt_disable();
	for (;;) {
		...
		preempt_disable();
	}
to:
	for (;;) {
		preempt_disable();
		...
	}

which seems more clean to me and saves a couple of bytes for
each function.

Signed-off-by: Oleg Nesterov &lt;oleg@tv-sign.ru&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch changes the code from:

	preempt_disable();
	for (;;) {
		...
		preempt_disable();
	}
to:
	for (;;) {
		preempt_disable();
		...
	}

which seems more clean to me and saves a couple of bytes for
each function.

Signed-off-by: Oleg Nesterov &lt;oleg@tv-sign.ru&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
