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From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org,
	oleg@redhat.com, paulmck@linux.vnet.ibm.com,
	rusty@rustcorp.com.au, mingo@kernel.org,
	akpm@linux-foundation.org, namhyung@kernel.org
Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com,
	xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu,
	fweisbec@gmail.com, linux@arm.linux.org.uk,
	nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com,
	linux-pm@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	walken@google.com, vincent.guittot@linaro.org
Subject: [PATCH v6 07/46] percpu_rwlock: Allow writers to be readers, and add lockdep annotations
Date: Mon, 18 Feb 2013 18:09:14 +0530	[thread overview]
Message-ID: <20130218123913.26245.7713.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com>

CPU hotplug (which will be the first user of per-CPU rwlocks) has a special
requirement with respect to locking: the writer, after acquiring the per-CPU
rwlock for write, must be allowed to take the same lock for read, without
deadlocking and without getting complaints from lockdep. In comparison, this
is similar to what get_online_cpus()/put_online_cpus() does today: it allows
a hotplug writer (who holds the cpu_hotplug.lock mutex) to invoke it without
locking issues, because it silently returns if the caller is the hotplug
writer itself.

This can be easily achieved with per-CPU rwlocks as well (even without a
"is this a writer?" check) by incrementing the per-CPU refcount of the writer
immediately after taking the global rwlock for write, and then decrementing
the per-CPU refcount before releasing the global rwlock.
This ensures that any reader that comes along on that CPU while the writer is
active (on that same CPU), notices the non-zero value of the nested counter
and assumes that it is a nested read-side critical section and proceeds by
just incrementing the refcount. Thus we prevent the reader from taking the
global rwlock for read, which prevents the writer from deadlocking itself.

Add that support and teach lockdep about this special locking scheme so
that it knows that this sort of usage is valid. Also add the required lockdep
annotations to enable it to detect common locking problems with per-CPU
rwlocks.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

 lib/percpu-rwlock.c |   33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/lib/percpu-rwlock.c b/lib/percpu-rwlock.c
index ed36531..bf95e40 100644
--- a/lib/percpu-rwlock.c
+++ b/lib/percpu-rwlock.c
@@ -102,6 +102,10 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 
 	if (likely(!writer_active(pcpu_rwlock))) {
 		this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/* Pretend that we take global_rwlock for lockdep */
+		rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+				    0, 0, _RET_IP_);
 	} else {
 		/* Writer is active, so switch to global rwlock. */
 
@@ -126,6 +130,12 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		if (!writer_active(pcpu_rwlock)) {
 			this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 			read_unlock(&pcpu_rwlock->global_rwlock);
+
+			/*
+			 * Pretend that we take global_rwlock for lockdep
+			 */
+			rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+					    0, 0, _RET_IP_);
 		}
 	}
 
@@ -162,6 +172,13 @@ void percpu_read_unlock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		 */
 		smp_mb();
 		this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/*
+		 * Since this is the last decrement, it is time to pretend
+		 * to lockdep that we are releasing the read lock.
+		 */
+		rwlock_release(&pcpu_rwlock->global_rwlock.dep_map,
+			       1, _RET_IP_);
 	} else {
 		read_unlock(&pcpu_rwlock->global_rwlock);
 	}
@@ -200,6 +217,16 @@ void percpu_write_lock_irqsave(struct percpu_rwlock *pcpu_rwlock,
 
 	smp_mb(); /* Complete the wait-for-readers, before taking the lock */
 	write_lock_irqsave(&pcpu_rwlock->global_rwlock, *flags);
+
+	/*
+	 * It is desirable to allow the writer to acquire the percpu-rwlock
+	 * for read (if necessary), without deadlocking or getting complaints
+	 * from lockdep. To achieve that, just increment the reader_refcnt of
+	 * this CPU - that way, any attempt by the writer to acquire the
+	 * percpu-rwlock for read, will get treated as a case of nested percpu
+	 * reader, which is safe, from a locking perspective.
+	 */
+	this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 }
 
 void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
@@ -207,6 +234,12 @@ void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
 {
 	unsigned int cpu;
 
+	/*
+	 * Undo the special increment that we had done in the write-lock path
+	 * in order to allow writers to be readers.
+	 */
+	this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
 	/* Complete the critical section before clearing ->writer_signal */
 	smp_mb();
 


WARNING: multiple messages have this Message-ID (diff)
From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org,
	oleg@redhat.com, paulmck@linux.vnet.ibm.com,
	rusty@rustcorp.com.au, mingo@kernel.org,
	akpm@linux-foundation.org, namhyung@kernel.org
Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk,
	nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org,
	fweisbec@gmail.com, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, rostedt@goodmis.org,
	xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu,
	wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com,
	netdev@vger.kernel.org, vincent.guittot@linaro.org,
	walken@google.com, linuxppc-dev@lists.ozlabs.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v6 07/46] percpu_rwlock: Allow writers to be readers, and add lockdep annotations
Date: Mon, 18 Feb 2013 18:09:14 +0530	[thread overview]
Message-ID: <20130218123913.26245.7713.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com>

CPU hotplug (which will be the first user of per-CPU rwlocks) has a special
requirement with respect to locking: the writer, after acquiring the per-CPU
rwlock for write, must be allowed to take the same lock for read, without
deadlocking and without getting complaints from lockdep. In comparison, this
is similar to what get_online_cpus()/put_online_cpus() does today: it allows
a hotplug writer (who holds the cpu_hotplug.lock mutex) to invoke it without
locking issues, because it silently returns if the caller is the hotplug
writer itself.

This can be easily achieved with per-CPU rwlocks as well (even without a
"is this a writer?" check) by incrementing the per-CPU refcount of the writer
immediately after taking the global rwlock for write, and then decrementing
the per-CPU refcount before releasing the global rwlock.
This ensures that any reader that comes along on that CPU while the writer is
active (on that same CPU), notices the non-zero value of the nested counter
and assumes that it is a nested read-side critical section and proceeds by
just incrementing the refcount. Thus we prevent the reader from taking the
global rwlock for read, which prevents the writer from deadlocking itself.

Add that support and teach lockdep about this special locking scheme so
that it knows that this sort of usage is valid. Also add the required lockdep
annotations to enable it to detect common locking problems with per-CPU
rwlocks.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

 lib/percpu-rwlock.c |   33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/lib/percpu-rwlock.c b/lib/percpu-rwlock.c
index ed36531..bf95e40 100644
--- a/lib/percpu-rwlock.c
+++ b/lib/percpu-rwlock.c
@@ -102,6 +102,10 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 
 	if (likely(!writer_active(pcpu_rwlock))) {
 		this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/* Pretend that we take global_rwlock for lockdep */
+		rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+				    0, 0, _RET_IP_);
 	} else {
 		/* Writer is active, so switch to global rwlock. */
 
@@ -126,6 +130,12 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		if (!writer_active(pcpu_rwlock)) {
 			this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 			read_unlock(&pcpu_rwlock->global_rwlock);
+
+			/*
+			 * Pretend that we take global_rwlock for lockdep
+			 */
+			rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+					    0, 0, _RET_IP_);
 		}
 	}
 
@@ -162,6 +172,13 @@ void percpu_read_unlock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		 */
 		smp_mb();
 		this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/*
+		 * Since this is the last decrement, it is time to pretend
+		 * to lockdep that we are releasing the read lock.
+		 */
+		rwlock_release(&pcpu_rwlock->global_rwlock.dep_map,
+			       1, _RET_IP_);
 	} else {
 		read_unlock(&pcpu_rwlock->global_rwlock);
 	}
@@ -200,6 +217,16 @@ void percpu_write_lock_irqsave(struct percpu_rwlock *pcpu_rwlock,
 
 	smp_mb(); /* Complete the wait-for-readers, before taking the lock */
 	write_lock_irqsave(&pcpu_rwlock->global_rwlock, *flags);
+
+	/*
+	 * It is desirable to allow the writer to acquire the percpu-rwlock
+	 * for read (if necessary), without deadlocking or getting complaints
+	 * from lockdep. To achieve that, just increment the reader_refcnt of
+	 * this CPU - that way, any attempt by the writer to acquire the
+	 * percpu-rwlock for read, will get treated as a case of nested percpu
+	 * reader, which is safe, from a locking perspective.
+	 */
+	this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 }
 
 void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
@@ -207,6 +234,12 @@ void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
 {
 	unsigned int cpu;
 
+	/*
+	 * Undo the special increment that we had done in the write-lock path
+	 * in order to allow writers to be readers.
+	 */
+	this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
 	/* Complete the critical section before clearing ->writer_signal */
 	smp_mb();
 

WARNING: multiple messages have this Message-ID (diff)
From: srivatsa.bhat@linux.vnet.ibm.com (Srivatsa S. Bhat)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v6 07/46] percpu_rwlock: Allow writers to be readers, and add lockdep annotations
Date: Mon, 18 Feb 2013 18:09:14 +0530	[thread overview]
Message-ID: <20130218123913.26245.7713.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com>

CPU hotplug (which will be the first user of per-CPU rwlocks) has a special
requirement with respect to locking: the writer, after acquiring the per-CPU
rwlock for write, must be allowed to take the same lock for read, without
deadlocking and without getting complaints from lockdep. In comparison, this
is similar to what get_online_cpus()/put_online_cpus() does today: it allows
a hotplug writer (who holds the cpu_hotplug.lock mutex) to invoke it without
locking issues, because it silently returns if the caller is the hotplug
writer itself.

This can be easily achieved with per-CPU rwlocks as well (even without a
"is this a writer?" check) by incrementing the per-CPU refcount of the writer
immediately after taking the global rwlock for write, and then decrementing
the per-CPU refcount before releasing the global rwlock.
This ensures that any reader that comes along on that CPU while the writer is
active (on that same CPU), notices the non-zero value of the nested counter
and assumes that it is a nested read-side critical section and proceeds by
just incrementing the refcount. Thus we prevent the reader from taking the
global rwlock for read, which prevents the writer from deadlocking itself.

Add that support and teach lockdep about this special locking scheme so
that it knows that this sort of usage is valid. Also add the required lockdep
annotations to enable it to detect common locking problems with per-CPU
rwlocks.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

 lib/percpu-rwlock.c |   33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/lib/percpu-rwlock.c b/lib/percpu-rwlock.c
index ed36531..bf95e40 100644
--- a/lib/percpu-rwlock.c
+++ b/lib/percpu-rwlock.c
@@ -102,6 +102,10 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 
 	if (likely(!writer_active(pcpu_rwlock))) {
 		this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/* Pretend that we take global_rwlock for lockdep */
+		rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+				    0, 0, _RET_IP_);
 	} else {
 		/* Writer is active, so switch to global rwlock. */
 
@@ -126,6 +130,12 @@ void percpu_read_lock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		if (!writer_active(pcpu_rwlock)) {
 			this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 			read_unlock(&pcpu_rwlock->global_rwlock);
+
+			/*
+			 * Pretend that we take global_rwlock for lockdep
+			 */
+			rwlock_acquire_read(&pcpu_rwlock->global_rwlock.dep_map,
+					    0, 0, _RET_IP_);
 		}
 	}
 
@@ -162,6 +172,13 @@ void percpu_read_unlock_irqsafe(struct percpu_rwlock *pcpu_rwlock)
 		 */
 		smp_mb();
 		this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
+		/*
+		 * Since this is the last decrement, it is time to pretend
+		 * to lockdep that we are releasing the read lock.
+		 */
+		rwlock_release(&pcpu_rwlock->global_rwlock.dep_map,
+			       1, _RET_IP_);
 	} else {
 		read_unlock(&pcpu_rwlock->global_rwlock);
 	}
@@ -200,6 +217,16 @@ void percpu_write_lock_irqsave(struct percpu_rwlock *pcpu_rwlock,
 
 	smp_mb(); /* Complete the wait-for-readers, before taking the lock */
 	write_lock_irqsave(&pcpu_rwlock->global_rwlock, *flags);
+
+	/*
+	 * It is desirable to allow the writer to acquire the percpu-rwlock
+	 * for read (if necessary), without deadlocking or getting complaints
+	 * from lockdep. To achieve that, just increment the reader_refcnt of
+	 * this CPU - that way, any attempt by the writer to acquire the
+	 * percpu-rwlock for read, will get treated as a case of nested percpu
+	 * reader, which is safe, from a locking perspective.
+	 */
+	this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);
 }
 
 void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
@@ -207,6 +234,12 @@ void percpu_write_unlock_irqrestore(struct percpu_rwlock *pcpu_rwlock,
 {
 	unsigned int cpu;
 
+	/*
+	 * Undo the special increment that we had done in the write-lock path
+	 * in order to allow writers to be readers.
+	 */
+	this_cpu_dec(pcpu_rwlock->rw_state->reader_refcnt);
+
 	/* Complete the critical section before clearing ->writer_signal */
 	smp_mb();
 

  parent reply	other threads:[~2013-02-18 12:41 UTC|newest]

Thread overview: 360+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-18 12:38 [PATCH v6 00/46] CPU hotplug: stop_machine()-free CPU hotplug Srivatsa S. Bhat
2013-02-18 12:38 ` Srivatsa S. Bhat
2013-02-18 12:38 ` Srivatsa S. Bhat
2013-02-18 12:38 ` [PATCH v6 01/46] percpu_rwlock: Introduce the global reader-writer lock backend Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38 ` [PATCH v6 02/46] percpu_rwlock: Introduce per-CPU variables for the reader and the writer Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38 ` [PATCH v6 03/46] percpu_rwlock: Provide a way to define and init percpu-rwlocks at compile time Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38 ` [PATCH v6 04/46] percpu_rwlock: Implement the core design of Per-CPU Reader-Writer Locks Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 12:38   ` Srivatsa S. Bhat
2013-02-18 15:45   ` Michel Lespinasse
2013-02-18 15:45     ` Michel Lespinasse
2013-02-18 15:45     ` Michel Lespinasse
2013-02-18 16:21     ` Srivatsa S. Bhat
2013-02-18 16:21       ` Srivatsa S. Bhat
2013-02-18 16:21       ` Srivatsa S. Bhat
2013-02-18 16:31       ` Steven Rostedt
2013-02-18 16:31         ` Steven Rostedt
2013-02-18 16:31         ` Steven Rostedt
2013-02-18 16:46         ` Srivatsa S. Bhat
2013-02-18 16:46           ` Srivatsa S. Bhat
2013-02-18 16:46           ` Srivatsa S. Bhat
2013-02-18 17:56       ` Srivatsa S. Bhat
2013-02-18 17:56         ` Srivatsa S. Bhat
2013-02-18 17:56         ` Srivatsa S. Bhat
2013-02-18 18:07         ` Michel Lespinasse
2013-02-18 18:07           ` Michel Lespinasse
2013-02-18 18:07           ` Michel Lespinasse
2013-02-18 18:14           ` Srivatsa S. Bhat
2013-02-18 18:14             ` Srivatsa S. Bhat
2013-02-18 18:14             ` Srivatsa S. Bhat
2013-02-25 15:53             ` Lai Jiangshan
2013-02-25 15:53               ` Lai Jiangshan
2013-02-25 15:53               ` Lai Jiangshan
2013-02-25 15:53               ` Lai Jiangshan
2013-02-25 19:26               ` Srivatsa S. Bhat
2013-02-25 19:26                 ` Srivatsa S. Bhat
2013-02-25 19:26                 ` Srivatsa S. Bhat
2013-02-26  0:17                 ` Lai Jiangshan
2013-02-26  0:17                   ` Lai Jiangshan
2013-02-26  0:17                   ` Lai Jiangshan
2013-02-26  0:19                   ` Lai Jiangshan
2013-02-26  0:19                     ` Lai Jiangshan
2013-02-26  0:19                     ` Lai Jiangshan
2013-02-26  9:02                   ` Srivatsa S. Bhat
2013-02-26  9:02                     ` Srivatsa S. Bhat
2013-02-26  9:02                     ` Srivatsa S. Bhat
2013-02-26 12:59                     ` Lai Jiangshan
2013-02-26 12:59                       ` Lai Jiangshan
2013-02-26 12:59                       ` Lai Jiangshan
2013-02-26 14:22                       ` Srivatsa S. Bhat
2013-02-26 14:22                         ` Srivatsa S. Bhat
2013-02-26 14:22                         ` Srivatsa S. Bhat
2013-02-26 16:25                         ` Lai Jiangshan
2013-02-26 16:25                           ` Lai Jiangshan
2013-02-26 16:25                           ` Lai Jiangshan
2013-02-26 19:30                           ` Srivatsa S. Bhat
2013-02-26 19:30                             ` Srivatsa S. Bhat
2013-02-26 19:30                             ` Srivatsa S. Bhat
2013-02-27  0:33                             ` Lai Jiangshan
2013-02-27  0:33                               ` Lai Jiangshan
2013-02-27  0:33                               ` Lai Jiangshan
2013-02-27 21:19                               ` Srivatsa S. Bhat
2013-02-27 21:19                                 ` Srivatsa S. Bhat
2013-02-27 21:19                                 ` Srivatsa S. Bhat
2013-02-27 21:19                                 ` Srivatsa S. Bhat
2013-03-01 17:44                                 ` [PATCH] lglock: add read-preference local-global rwlock Lai Jiangshan
2013-03-01 17:44                                   ` Lai Jiangshan
2013-03-01 17:44                                   ` Lai Jiangshan
2013-03-01 17:44                                   ` Lai Jiangshan
2013-03-01 17:44                                   ` Lai Jiangshan
2013-03-01 17:44                                   ` Lai Jiangshan
2013-03-01 17:53                                   ` Tejun Heo
2013-03-01 17:53                                     ` Tejun Heo
2013-03-01 17:53                                     ` Tejun Heo
2013-03-01 20:06                                     ` Srivatsa S. Bhat
2013-03-01 20:06                                       ` Srivatsa S. Bhat
2013-03-01 20:06                                       ` Srivatsa S. Bhat
2013-03-01 18:28                                   ` Oleg Nesterov
2013-03-01 18:28                                     ` Oleg Nesterov
2013-03-01 18:28                                     ` Oleg Nesterov
2013-03-02 12:13                                     ` Michel Lespinasse
2013-03-02 12:13                                       ` Michel Lespinasse
2013-03-02 12:13                                       ` Michel Lespinasse
2013-03-02 12:13                                       ` Michel Lespinasse
2013-03-02 13:14                                       ` [PATCH V2] " Lai Jiangshan
2013-03-02 13:14                                         ` Lai Jiangshan
2013-03-02 13:14                                         ` Lai Jiangshan
2013-03-02 13:14                                         ` Lai Jiangshan
2013-03-02 13:14                                         ` Lai Jiangshan
2013-03-02 17:11                                         ` Srivatsa S. Bhat
2013-03-02 17:11                                           ` Srivatsa S. Bhat
2013-03-02 17:11                                           ` Srivatsa S. Bhat
2013-03-05 15:41                                           ` Lai Jiangshan
2013-03-05 15:41                                             ` Lai Jiangshan
2013-03-05 15:41                                             ` Lai Jiangshan
2013-03-05 17:55                                             ` Srivatsa S. Bhat
2013-03-05 17:55                                               ` Srivatsa S. Bhat
2013-03-05 17:55                                               ` Srivatsa S. Bhat
2013-03-02 17:20                                         ` Oleg Nesterov
2013-03-02 17:20                                           ` Oleg Nesterov
2013-03-02 17:20                                           ` Oleg Nesterov
2013-03-03 17:40                                           ` Oleg Nesterov
2013-03-03 17:40                                             ` Oleg Nesterov
2013-03-03 17:40                                             ` Oleg Nesterov
2013-03-05  1:37                                             ` Michel Lespinasse
2013-03-05  1:37                                               ` Michel Lespinasse
2013-03-05  1:37                                               ` Michel Lespinasse
2013-03-05 15:27                                           ` Lai Jiangshan
2013-03-05 15:27                                             ` Lai Jiangshan
2013-03-05 15:27                                             ` Lai Jiangshan
2013-03-05 16:19                                             ` Michel Lespinasse
2013-03-05 16:19                                               ` Michel Lespinasse
2013-03-05 16:19                                               ` Michel Lespinasse
2013-03-05 16:41                                             ` Oleg Nesterov
2013-03-05 16:41                                               ` Oleg Nesterov
2013-03-05 16:41                                               ` Oleg Nesterov
2013-03-02 17:06                                       ` [PATCH] " Oleg Nesterov
2013-03-02 17:06                                         ` Oleg Nesterov
2013-03-02 17:06                                         ` Oleg Nesterov
2013-03-05 15:54                                         ` Lai Jiangshan
2013-03-05 15:54                                           ` Lai Jiangshan
2013-03-05 15:54                                           ` Lai Jiangshan
2013-03-05 16:32                                           ` Michel Lespinasse
2013-03-05 16:32                                             ` Michel Lespinasse
2013-03-05 16:32                                             ` Michel Lespinasse
2013-03-05 16:35                                           ` Oleg Nesterov
2013-03-05 16:35                                             ` Oleg Nesterov
2013-03-05 16:35                                             ` Oleg Nesterov
2013-03-02 13:42                                     ` Lai Jiangshan
2013-03-02 13:42                                       ` Lai Jiangshan
2013-03-02 13:42                                       ` Lai Jiangshan
2013-03-02 17:01                                       ` Oleg Nesterov
2013-03-02 17:01                                         ` Oleg Nesterov
2013-03-02 17:01                                         ` Oleg Nesterov
2013-03-01 17:50                                 ` [PATCH v6 04/46] percpu_rwlock: Implement the core design of Per-CPU Reader-Writer Locks Lai Jiangshan
2013-03-01 17:50                                   ` Lai Jiangshan
2013-03-01 17:50                                   ` Lai Jiangshan
2013-03-01 17:50                                   ` Lai Jiangshan
2013-03-01 19:47                                   ` Srivatsa S. Bhat
2013-03-01 19:47                                     ` Srivatsa S. Bhat
2013-03-01 19:47                                     ` Srivatsa S. Bhat
2013-03-01 19:47                                     ` Srivatsa S. Bhat
2013-03-05 16:25                                     ` Lai Jiangshan
2013-03-05 16:25                                       ` Lai Jiangshan
2013-03-05 16:25                                       ` Lai Jiangshan
2013-03-05 16:25                                       ` Lai Jiangshan
2013-03-05 18:27                                       ` Srivatsa S. Bhat
2013-03-05 18:27                                         ` Srivatsa S. Bhat
2013-03-05 18:27                                         ` Srivatsa S. Bhat
2013-03-05 18:27                                         ` Srivatsa S. Bhat
2013-03-01 18:10                                 ` Tejun Heo
2013-03-01 18:10                                   ` Tejun Heo
2013-03-01 18:10                                   ` Tejun Heo
2013-03-01 19:59                                   ` Srivatsa S. Bhat
2013-03-01 19:59                                     ` Srivatsa S. Bhat
2013-03-01 19:59                                     ` Srivatsa S. Bhat
2013-02-27 11:11                             ` Michel Lespinasse
2013-02-27 11:11                               ` Michel Lespinasse
2013-02-27 11:11                               ` Michel Lespinasse
2013-02-27 19:25                               ` Oleg Nesterov
2013-02-27 19:25                                 ` Oleg Nesterov
2013-02-27 19:25                                 ` Oleg Nesterov
2013-02-28 11:34                                 ` Michel Lespinasse
2013-02-28 11:34                                   ` Michel Lespinasse
2013-02-28 11:34                                   ` Michel Lespinasse
2013-02-28 18:00                                   ` Oleg Nesterov
2013-02-28 18:00                                     ` Oleg Nesterov
2013-02-28 18:00                                     ` Oleg Nesterov
2013-02-28 18:20                                     ` Oleg Nesterov
2013-02-28 18:20                                       ` Oleg Nesterov
2013-02-28 18:20                                       ` Oleg Nesterov
2013-02-26 13:34                 ` Lai Jiangshan
2013-02-26 13:34                   ` Lai Jiangshan
2013-02-26 13:34                   ` Lai Jiangshan
2013-02-26 15:17                   ` Srivatsa S. Bhat
2013-02-26 15:17                     ` Srivatsa S. Bhat
2013-02-26 14:17   ` Lai Jiangshan
2013-02-26 14:17     ` Lai Jiangshan
2013-02-26 14:17     ` Lai Jiangshan
2013-02-26 14:37     ` Srivatsa S. Bhat
2013-02-26 14:37       ` Srivatsa S. Bhat
2013-02-26 14:37       ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 05/46] percpu_rwlock: Make percpu-rwlocks IRQ-safe, optimally Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 06/46] percpu_rwlock: Rearrange the read-lock code to fastpath nested percpu readers Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39 ` Srivatsa S. Bhat [this message]
2013-02-18 12:39   ` [PATCH v6 07/46] percpu_rwlock: Allow writers to be readers, and add lockdep annotations Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 15:51   ` Michel Lespinasse
2013-02-18 15:51     ` Michel Lespinasse
2013-02-18 15:51     ` Michel Lespinasse
2013-02-18 16:31     ` Srivatsa S. Bhat
2013-02-18 16:31       ` Srivatsa S. Bhat
2013-02-18 16:31       ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 08/46] CPU hotplug: Provide APIs to prevent CPU offline from atomic context Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 16:23   ` Michel Lespinasse
2013-02-18 16:23     ` Michel Lespinasse
2013-02-18 16:23     ` Michel Lespinasse
2013-02-18 16:43     ` Srivatsa S. Bhat
2013-02-18 16:43       ` Srivatsa S. Bhat
2013-02-18 16:43       ` Srivatsa S. Bhat
2013-02-18 17:21       ` Michel Lespinasse
2013-02-18 17:21         ` Michel Lespinasse
2013-02-18 17:21         ` Michel Lespinasse
2013-02-18 18:50         ` Srivatsa S. Bhat
2013-02-18 18:50           ` Srivatsa S. Bhat
2013-02-18 18:50           ` Srivatsa S. Bhat
2013-02-19  9:40           ` Michel Lespinasse
2013-02-19  9:40             ` Michel Lespinasse
2013-02-19  9:40             ` Michel Lespinasse
2013-02-19  9:55             ` Srivatsa S. Bhat
2013-02-19  9:55               ` Srivatsa S. Bhat
2013-02-19  9:55               ` Srivatsa S. Bhat
2013-02-19 10:42               ` David Laight
2013-02-19 10:42                 ` David Laight
2013-02-19 10:42                 ` David Laight
2013-02-19 10:42                 ` David Laight
2013-02-19 10:58                 ` Srivatsa S. Bhat
2013-02-19 10:58                   ` Srivatsa S. Bhat
2013-02-19 10:58                   ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 09/46] CPU hotplug: Convert preprocessor macros to static inline functions Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 10/46] smp, cpu hotplug: Fix smp_call_function_*() to prevent CPU offline properly Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39 ` [PATCH v6 11/46] smp, cpu hotplug: Fix on_each_cpu_*() " Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:39   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 12/46] sched/timer: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 13/46] sched/migration: Use raw_spin_lock/unlock since interrupts are already disabled Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 14/46] sched/rt: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 15/46] tick: " Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 16/46] time/clocksource: " Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 17/46] clockevents: Use get/put_online_cpus_atomic() in clockevents_notify() Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 18/46] softirq: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40 ` [PATCH v6 19/46] irq: " Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:40   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 20/46] net: " Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 21/46] block: " Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 22/46] crypto: pcrypt - Protect access to cpu_online_mask with get/put_online_cpus() Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 23/46] infiniband: ehca: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 24/46] [SCSI] fcoe: " Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 25/46] staging: octeon: " Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41 ` [PATCH v6 26/46] x86: " Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:41   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 27/46] perf/x86: " Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 28/46] KVM: Use get/put_online_cpus_atomic() to prevent CPU offline from atomic context Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 29/46] kvm/vmx: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 30/46] x86/xen: " Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 31/46] alpha/smp: " Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 32/46] blackfin/smp: " Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42 ` [PATCH v6 33/46] cris/smp: " Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 12:42   ` Srivatsa S. Bhat
2013-02-18 13:07   ` Jesper Nilsson
2013-02-18 13:07     ` Jesper Nilsson
2013-02-18 13:07     ` Jesper Nilsson
2013-02-18 12:43 ` [PATCH v6 34/46] hexagon/smp: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 35/46] ia64: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 36/46] m32r: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 37/46] MIPS: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 38/46] mn10300: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 39/46] parisc: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43 ` [PATCH v6 40/46] powerpc: " Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:43   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 41/46] sh: " Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 42/46] sparc: " Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 43/46] tile: " Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 44/46] cpu: No more __stop_machine() in _cpu_down() Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 45/46] CPU hotplug, stop_machine: Decouple CPU hotplug from stop_machine() in Kconfig Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44 ` [PATCH v6 46/46] Documentation/cpu-hotplug: Remove references to stop_machine() Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-18 12:44   ` Srivatsa S. Bhat
2013-02-22  0:31 ` [PATCH v6 00/46] CPU hotplug: stop_machine()-free CPU hotplug Rusty Russell
2013-02-22  0:31   ` Rusty Russell
2013-02-22  0:31   ` Rusty Russell
2013-02-22  0:31   ` Rusty Russell
2013-02-22  0:31   ` Rusty Russell
2013-02-25 21:45   ` Srivatsa S. Bhat
2013-02-25 21:45     ` Srivatsa S. Bhat
2013-02-25 21:45     ` Srivatsa S. Bhat
2013-03-01 12:05 ` Vincent Guittot
2013-03-01 12:05   ` Vincent Guittot
2013-03-01 12:05   ` Vincent Guittot

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