From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Sebastian A. Siewior" <bigeasy@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
LKML <linux-kernel@vger.kernel.org>,
"Ahmed S. Darwish" <a.darwish@linutronix.de>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org
Subject: [PATCH v1 09/25] Documentation: locking: Describe seqlock design and usage
Date: Tue, 19 May 2020 23:45:31 +0200 [thread overview]
Message-ID: <20200519214547.352050-10-a.darwish@linutronix.de> (raw)
In-Reply-To: <20200519214547.352050-1-a.darwish@linutronix.de>
Proper documentation for the design and usage of sequence counters and
sequential locks does not exist. Complete the seqlock.h documentation as
follows:
- Divide all documentation on a seqcount_t vs. seqlock_t basis. The
description for both mechanisms was intermingled, which is incorrect
since the usage constrains for each type are vastly different.
- Add an introductory paragraph describing the internal design of, and
rationale for, sequence counters.
- Document seqcount_t writer non-preemptibility requirement, which was
not previously documented anywhere, and provide a clear rationale.
- Provide template code for seqcount_t and seqlock_t initialization
and reader/writer critical sections.
- Recommend using seqlock_t by default. It implicitly handles the
serialization and non-preemptibility requirements of writers.
At seqlock.h:
- Remove references to brlocks as they've long been removed from the
kernel.
- Remove references to gcc-3.x since the kernel's minimum supported
gcc version is 4.6.
- Remove the severely lacking top comment and reference the newly
introduced Documentation/locking/seqlock.rst file instead.
References: 0f6ed63b1707 ("no need to keep brlock macros anymore...")
References: cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
---
Documentation/locking/index.rst | 1 +
Documentation/locking/seqlock.rst | 181 ++++++++++++++++++++++++++++++
include/linux/seqlock.h | 73 +++++-------
3 files changed, 213 insertions(+), 42 deletions(-)
create mode 100644 Documentation/locking/seqlock.rst
diff --git a/Documentation/locking/index.rst b/Documentation/locking/index.rst
index 5d6800a723dc..aad15fc81ccd 100644
--- a/Documentation/locking/index.rst
+++ b/Documentation/locking/index.rst
@@ -14,6 +14,7 @@ locking
mutex-design
rt-mutex-design
rt-mutex
+ seqlock
spinlocks
ww-mutex-design
diff --git a/Documentation/locking/seqlock.rst b/Documentation/locking/seqlock.rst
new file mode 100644
index 000000000000..2242ae00e7bf
--- /dev/null
+++ b/Documentation/locking/seqlock.rst
@@ -0,0 +1,181 @@
+======================================
+Sequence counters and sequential locks
+======================================
+
+Introduction
+============
+
+Sequence counters are a reader-writer consistency mechanism with
+lockless readers (read-only retry loops), and no writer starvation. They
+are used for data that's rarely written to (e.g. system time), where the
+reader wants a consistent set of information and is willing to retry if
+that information changes.
+
+A data set is consistent when the sequence count at the beginning of the
+read side critical section is even and the same sequence count value is
+read again at the end of the critical section. The data in the set must
+be copied out inside the read side critical section. If the sequence
+count has changed between the start and the end of the critical section,
+the reader must retry.
+
+Writers increment the sequence count at the start and the end of their
+critical section. After starting the critical section the sequence count
+is odd and indicates to the readers that an update is in progress. At
+the end of the write side critical section the sequence count becomes
+even again which lets readers make progress.
+
+A sequence counter write side critical section must never be preempted
+or interrupted by read side sections. Otherwise the reader will spin for
+the entire scheduler tick due to the odd sequence count value and the
+interrupted writer. If that reader belongs to a real-time scheduling
+class, it can spin forever and the kernel will livelock.
+
+.. _seqcount_t:
+
+Sequence counters (:c:type:`seqcount_t`)
+========================================
+
+This is the the raw counting mechanism, which does not protect against
+multiple writers. Write side critical sections must thus be serialized
+by an external lock.
+
+If the write serialization primitive is not implicitly disabling
+preemption, preemption must be explicitly disabled before entering the
+write side section. If the sequence counter read section can be invoked
+from hardirq or softirq contexts, interrupts or bottom halves must be
+respectively disabled before entering the write side section.
+
+If it's desired to automatically handle the sequence counter
+requirements of writer serialization and non-preemptibility, use a
+:ref:`sequential lock <seqlock_t>` instead.
+
+Initialization:
+
+.. code-block:: c
+
+ /* dynamic */
+ seqcount_t foo_seqcount;
+ seqcount_init(&foo_seqcount);
+
+ /* static */
+ static seqcount_t foo_seqcount = SEQCNT_ZERO(foo_seqcount);
+
+ /* C99 struct init */
+ struct {
+ .seq = SEQCNT_ZERO(foo.seq),
+ } foo;
+
+Write path:
+
+.. code-block:: c
+
+ /* Serialized context with disabled preemption */
+
+ write_seqcount_begin(&foo_seqcount);
+
+ /* ... [[write-side critical section]] ... */
+
+ write_seqcount_end(&foo_seqcount);
+
+Read path:
+
+.. code-block:: c
+
+ do {
+ seq = read_seqcount_begin(&foo_seqcount);
+
+ /* ... [[read-side critical section]] ... */
+
+ } while (read_seqcount_retry(&foo_seqcount, seq));
+
+.. _seqlock_t:
+
+Sequential locks (:c:type:`seqlock_t`)
+======================================
+
+This contains the :ref:`sequence counting mechanism <seqcount_t>`
+earlier discussed, plus an embedded spinlock for writer serialization
+and non-preemptibility.
+
+If the read side section can be invoked from hardirq or softirq context,
+use the write side function variants which respectively disable
+interrupts or bottom halves.
+
+Initialization:
+
+.. code-block:: c
+
+ /* dynamic */
+ seqlock_t foo_seqlock;
+ seqlock_init(&foo_seqlock);
+
+ /* static */
+ static DEFINE_SEQLOCK(foo_seqlock);
+
+ /* C99 struct init */
+ struct {
+ .seql = __SEQLOCK_UNLOCKED(foo.seql)
+ } foo;
+
+Write path:
+
+.. code-block:: c
+
+ write_seqlock(&foo_seqlock);
+
+ /* ... [[write-side critical section]] ... */
+
+ write_sequnlock(&foo_seqlock);
+
+Read path, three categories:
+
+1. Normal Sequence readers which never block a writer but they must
+ retry if a writer is in progress by detecting change in the sequence
+ number. Writers do not wait for a sequence reader.
+
+ .. code-block:: c
+
+ do {
+ seq = read_seqbegin(&foo_seqlock);
+
+ /* ... [[read-side critical section]] ... */
+
+ } while (read_seqretry(&foo_seqlock, seq));
+
+2. Locking readers which will wait if a writer or another locking reader
+ is in progress. A locking reader in progress will also block a writer
+ from entering its critical section. This read lock is
+ exclusive. Unlike rwlock_t, only one locking reader can acquire it.
+
+ .. code-block:: c
+
+ read_seqlock_excl(&foo_seqlock);
+
+ /* ... [[read-side critical section]] ... */
+
+ read_sequnlock_excl(&foo_seqlock);
+
+3. Conditional lockless reader (as in 1), or locking reader (as in 2),
+ according to a passed marker. This is used to avoid lockless readers
+ starvation (too much retry loops) in case of a sharp spike in write
+ activity. First, a lockless read is tried (even marker passed). If
+ that trial fails (odd sequence counter is returned, which is used as
+ the next iteration marker), the lockless read is transformed to a
+ full locking read and no retry loop is necessary.
+
+ .. code-block:: c
+
+ /* marker; even initialization */
+ int seq = 0;
+ do {
+ read_seqbegin_or_lock(&foo_seqlock, &seq);
+
+ /* ... [[read-side critical section]] ... */
+
+ } while (need_seqretry(&foo_seqlock, seq));
+ done_seqretry(&foo_seqlock, seq);
+
+API documentation
+=================
+
+.. kernel-doc:: include/linux/seqlock.h
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index d35be7709403..2a4af746b1da 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -1,36 +1,15 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_SEQLOCK_H
#define __LINUX_SEQLOCK_H
+
/*
- * Reader/writer consistent mechanism without starving writers. This type of
- * lock for data where the reader wants a consistent set of information
- * and is willing to retry if the information changes. There are two types
- * of readers:
- * 1. Sequence readers which never block a writer but they may have to retry
- * if a writer is in progress by detecting change in sequence number.
- * Writers do not wait for a sequence reader.
- * 2. Locking readers which will wait if a writer or another locking reader
- * is in progress. A locking reader in progress will also block a writer
- * from going forward. Unlike the regular rwlock, the read lock here is
- * exclusive so that only one locking reader can get it.
+ * seqcount_t / seqlock_t - a reader-writer consistency mechanism with
+ * lockless readers (read-only retry loops), and no writer starvation.
*
- * This is not as cache friendly as brlock. Also, this may not work well
- * for data that contains pointers, because any writer could
- * invalidate a pointer that a reader was following.
+ * See Documentation/locking/seqlock.rst for full description.
*
- * Expected non-blocking reader usage:
- * do {
- * seq = read_seqbegin(&foo);
- * ...
- * } while (read_seqretry(&foo, seq));
- *
- *
- * On non-SMP the spin locks disappear but the writer still needs
- * to increment the sequence variables because an interrupt routine could
- * change the state of the data.
- *
- * Based on x86_64 vsyscall gettimeofday
- * by Keith Owens and Andrea Arcangeli
+ * Copyrights:
+ * - Based on x86_64 vsyscall gettimeofday: Keith Owens, Andrea Arcangeli
*/
#include <linux/spinlock.h>
@@ -40,11 +19,23 @@
#include <asm/processor.h>
/*
- * Version using sequence counter only.
- * This can be used when code has its own mutex protecting the
- * updating starting before the write_seqcountbeqin() and ending
- * after the write_seqcount_end().
+ * Sequence counters (seqcount_t)
+ *
+ * The raw counting mechanism without any writer protection. Write side
+ * critical sections must be serialized and readers on the same CPU
+ * (e.g. through preemption or interrupts) must be excluded.
+ *
+ * If the write serialization mechanism is one of the common kernel
+ * locking primitives, use a sequence counter with associated lock
+ * (seqcount_LOCKTYPE_t) instead.
+ *
+ * If it's desired to automatically handle the sequence counter writer
+ * serialization and non-preemptibility requirements, use a sequential
+ * lock (seqlock_t) instead.
+ *
+ * See Documentation/locking/seqlock.rst
*/
+
typedef struct seqcount {
unsigned sequence;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -221,8 +212,6 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
return __read_seqcount_retry(s, start);
}
-
-
static inline void raw_write_seqcount_begin(seqcount_t *s)
{
s->sequence++;
@@ -367,11 +356,6 @@ static inline void raw_write_seqcount_latch(seqcount_t *s)
smp_wmb(); /* increment "sequence" before following stores */
}
-/*
- * Sequence counter only version assumes that callers are using their
- * own locking and preemption is disabled.
- */
-
static inline void __write_seqcount_begin_nested(seqcount_t *s, int subclass)
{
raw_write_seqcount_begin(s);
@@ -419,15 +403,20 @@ static inline void write_seqcount_invalidate(seqcount_t *s)
s->sequence+=2;
}
+/*
+ * Sequential locks (seqlock_t)
+ *
+ * Sequence counters with an embedded spinlock for writer serialization
+ * and non-preemptibility.
+ *
+ * See Documentation/locking/seqlock.rst
+ */
+
typedef struct {
struct seqcount seqcount;
spinlock_t lock;
} seqlock_t;
-/*
- * These macros triggered gcc-3.x compile-time problems. We think these are
- * OK now. Be cautious.
- */
#define __SEQLOCK_UNLOCKED(lockname) \
{ \
.seqcount = SEQCNT_ZERO(lockname), \
--
2.20.1
next prev parent reply other threads:[~2020-05-19 21:47 UTC|newest]
Thread overview: 258+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 21:45 [PATCH v1 00/25] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 01/25] net: core: device_rename: Use rwsem instead of a seqcount Ahmed S. Darwish
2020-05-19 22:01 ` Stephen Hemminger
2020-05-19 22:23 ` Thomas Gleixner
2020-05-19 23:11 ` Stephen Hemminger
2020-05-19 23:42 ` Thomas Gleixner
2020-05-20 0:06 ` Stephen Hemminger
2020-05-20 1:55 ` Thomas Gleixner
2020-05-20 2:57 ` David Miller
2020-05-20 3:18 ` Eric Dumazet
2020-05-20 4:36 ` Stephen Hemminger
2020-05-20 19:37 ` Thomas Gleixner
2020-05-20 21:36 ` Stephen Hemminger
2020-05-20 2:01 ` Eric Dumazet
2020-05-20 6:42 ` Ahmed S. Darwish
2020-05-20 12:51 ` Eric Dumazet
2020-06-03 14:33 ` Ahmed S. Darwish
2020-05-20 14:37 ` Dan Carpenter
2020-05-25 16:22 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 02/25] mm/swap: Don't abuse the seqcount latching API Ahmed S. Darwish
2020-05-20 12:22 ` Konstantin Khlebnikov
2020-05-20 13:05 ` Peter Zijlstra
2020-05-22 14:57 ` Peter Zijlstra
2020-05-22 15:17 ` Sebastian A. Siewior
2020-05-22 16:23 ` Peter Zijlstra
2020-05-25 15:24 ` Ahmed S. Darwish
2020-05-25 15:45 ` Peter Zijlstra
2020-05-25 16:10 ` John Ogness
2020-09-10 15:08 ` [tip: locking/core] mm/swap: Do not abuse the seqcount_t " tip-bot2 for Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 03/25] net: phy: fixed_phy: Remove unused seqcount Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 04/25] block: nr_sects_write(): Disable preemption on seqcount write Ahmed S. Darwish
2020-05-22 16:39 ` Peter Zijlstra
2020-05-25 9:56 ` Ahmed S. Darwish
[not found] ` <20200522001237.A00E8206BE@mail.kernel.org>
2020-05-25 10:12 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 05/25] u64_stats: Document writer non-preemptibility requirement Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 06/25] dma-buf: Remove custom seqcount lockdep class key Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 07/25] lockdep: Add preemption disabled assertion API Ahmed S. Darwish
2020-05-22 17:55 ` Peter Zijlstra
2020-05-23 14:59 ` Sebastian A. Siewior
2020-05-23 22:41 ` Peter Zijlstra
2020-05-24 10:50 ` Sebastian A. Siewior
2020-05-25 10:22 ` Peter Zijlstra
2020-05-26 0:52 ` Ahmed S. Darwish
2020-05-26 8:13 ` Peter Zijlstra
2020-05-26 9:45 ` Ahmed S. Darwish
2020-06-03 15:30 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 08/25] seqlock: lockdep assert non-preemptibility on seqcount_t write Ahmed S. Darwish
2020-05-19 21:45 ` Ahmed S. Darwish [this message]
2020-05-22 18:01 ` [PATCH v1 09/25] Documentation: locking: Describe seqlock design and usage Peter Zijlstra
2020-05-22 22:24 ` Steven Rostedt
2020-05-25 10:50 ` Ahmed S. Darwish
2020-05-25 11:02 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 10/25] seqlock: Add RST directives to kernel-doc code samples and notes Ahmed S. Darwish
2020-05-22 18:02 ` Peter Zijlstra
2020-05-22 18:03 ` Peter Zijlstra
2020-05-22 18:26 ` Thomas Gleixner
2020-05-22 18:32 ` Peter Zijlstra
2020-05-25 9:36 ` Ahmed S. Darwish
2020-05-25 13:44 ` Peter Zijlstra
2020-05-25 14:07 ` Peter Zijlstra
2020-05-19 21:45 ` [PATCH v1 11/25] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 12/25] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 13/25] dma-buf: Use sequence counter with associated wound/wait mutex Ahmed S. Darwish
2020-05-20 10:48 ` Christian König
2020-05-21 0:09 ` Ahmed S. Darwish
2020-05-21 13:20 ` Christian König
2020-05-19 21:45 ` [PATCH v1 14/25] sched: tasks: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 15/25] netfilter: conntrack: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 16/25] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 17/25] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 18/25] timekeeping: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 19/25] vfs: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 20/25] raid5: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 21/25] iocost: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 22/25] NFSv4: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 23/25] userfaultfd: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 24/25] kvm/eventfd: " Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 25/25] hrtimer: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 00/18] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 01/18] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 02/18] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 03/18] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 04/18] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 05/18] dma-buf: Remove custom seqcount lockdep class key Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 06/18] dma-buf: Use sequence counter with associated wound/wait mutex Ahmed S. Darwish
2020-06-08 14:32 ` Daniel Vetter
2020-06-08 0:57 ` [PATCH v2 07/18] sched: tasks: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 08/18] netfilter: conntrack: " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 09/18] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 10/18] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 11/18] timekeeping: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 12/18] vfs: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 13/18] raid5: " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 14/18] iocost: " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 15/18] NFSv4: " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 16/18] userfaultfd: " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 17/18] kvm/eventfd: " Ahmed S. Darwish
2020-06-08 12:57 ` Paolo Bonzini
2020-06-08 0:57 ` [PATCH v2 18/18] hrtimer: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 00/20] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 01/20] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-07-06 21:04 ` Peter Zijlstra
2020-07-06 21:12 ` Jonathan Corbet
2020-07-06 21:16 ` Peter Zijlstra
2020-07-07 10:12 ` Ahmed S. Darwish
2020-07-07 12:47 ` Peter Zijlstra
2020-06-30 5:44 ` [PATCH v3 02/20] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 03/20] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 04/20] lockdep: Add preemption enabled/disabled assertion APIs Ahmed S. Darwish
2020-07-06 20:50 ` Peter Zijlstra
2020-07-07 7:34 ` Sebastian A. Siewior
2020-06-30 5:44 ` [PATCH v3 05/20] seqlock: lockdep assert non-preemptibility on seqcount_t write Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 06/20] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-07-06 21:21 ` Peter Zijlstra
2020-07-07 8:40 ` Ahmed S. Darwish
2020-07-07 13:04 ` Peter Zijlstra
2020-07-07 14:37 ` Peter Zijlstra
2020-07-08 9:12 ` Peter Zijlstra
2020-07-08 10:43 ` Ahmed S. Darwish
2020-07-08 10:33 ` Ahmed S. Darwish
2020-07-08 12:29 ` Peter Zijlstra
2020-07-08 14:13 ` Peter Zijlstra
2020-07-08 14:25 ` Peter Zijlstra
2020-07-08 15:09 ` Ahmed S. Darwish
2020-07-08 15:35 ` Peter Zijlstra
2020-07-08 15:58 ` Ahmed S. Darwish
2020-07-08 16:16 ` Peter Zijlstra
2020-07-08 16:18 ` Peter Zijlstra
2020-07-08 16:01 ` Peter Zijlstra
2020-06-30 5:44 ` [PATCH v3 07/20] dma-buf: Remove custom seqcount lockdep class key Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 08/20] dma-buf: Use sequence counter with associated wound/wait mutex Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 09/20] sched: tasks: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 10/20] netfilter: conntrack: " Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 11/20] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 12/20] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 13/20] timekeeping: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 14/20] vfs: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 15/20] raid5: " Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 16/20] iocost: " Ahmed S. Darwish
2020-06-30 7:11 ` Daniel Wagner
2020-06-30 5:44 ` [PATCH v3 17/20] NFSv4: " Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 18/20] userfaultfd: " Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 19/20] kvm/eventfd: " Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 20/20] hrtimer: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 01/24] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-07-21 1:35 ` Steven Rostedt
2020-07-21 1:37 ` Steven Rostedt
2020-07-21 5:34 ` Ahmed S. Darwish
2020-07-21 1:44 ` Steven Rostedt
2020-07-21 1:51 ` Steven Rostedt
2020-07-21 7:15 ` Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 02/24] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 03/24] seqlock: seqcount_t latch: End read sections with read_seqcount_retry() Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 04/24] seqlock: Reorder seqcount_t and seqlock_t API definitions Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 05/24] seqlock: Add kernel-doc for seqcount_t and seqlock_t APIs Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 06/24] seqlock: Implement raw_seqcount_begin() in terms of raw_read_seqcount() Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 07/24] lockdep: Add preemption enabled/disabled assertion APIs Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 08/24] seqlock: lockdep assert non-preemptibility on seqcount_t write Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-08 23:21 ` [PATCH v4 08/24] " Guenter Roeck
2020-08-08 23:23 ` Guenter Roeck
2020-08-09 18:42 ` Ahmed S. Darwish
2020-08-10 8:59 ` Greg KH
2020-08-10 9:48 ` peterz
2020-08-10 10:03 ` Greg KH
2020-08-10 9:54 ` [PATCH] Revert "seqlock: lockdep assert non-preemptibility on seqcount_t write" Ahmed S. Darwish
2020-08-10 10:05 ` Greg KH
2020-08-10 10:35 ` Ahmed S. Darwish
2020-08-10 14:10 ` Guenter Roeck
2020-08-18 22:51 ` Valdis Klētnieks
2020-08-19 0:56 ` Guenter Roeck
2020-08-19 7:00 ` Sebastian Andrzej Siewior
2020-08-19 7:34 ` Valdis Klētnieks
2020-08-19 16:15 ` Guenter Roeck
2020-08-10 19:55 ` [PATCH v4 08/24] seqlock: lockdep assert non-preemptibility on seqcount_t write Thomas Gleixner
2020-08-11 10:06 ` Greg KH
2020-07-20 15:55 ` [PATCH v4 09/24] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 10/24] seqlock: Align multi-line macros newline escapes at 72 columns Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 11/24] dma-buf: Remove custom seqcount lockdep class key Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 12/24] dma-buf: Use sequence counter with associated wound/wait mutex Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 13/24] sched: tasks: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 14/24] netfilter: conntrack: " Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 15/24] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 16/24] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 17/24] timekeeping: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 18/24] vfs: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 19/24] raid5: " Ahmed S. Darwish
2020-07-22 6:40 ` Song Liu
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 20/24] iocost: " Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 21/24] NFSv4: " Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 22/24] userfaultfd: " Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 23/24] kvm/eventfd: " Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 24/24] hrtimer: Use sequence counter with associated raw spinlock Ahmed S. Darwish
2020-07-29 14:33 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-07-20 16:49 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Eric Biggers
2020-07-20 17:33 ` Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 0/8] seqlock: Introduce seqcount_latch_t Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 1/8] time/sched_clock: Use raw_read_seqcount_latch() during suspend Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 2/8] mm/swap: Do not abuse the seqcount_t latching API Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 3/8] seqlock: Introduce seqcount_latch_t Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 4/8] time/sched_clock: Use seqcount_latch_t Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 5/8] timekeeping: " Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 6/8] x86/tsc: " Ahmed S. Darwish
2020-09-04 7:41 ` peterz
2020-09-04 8:03 ` peterz
2020-09-07 16:29 ` Ahmed S. Darwish
2020-09-07 17:30 ` peterz
2020-09-08 6:23 ` Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 7/8] rbtree_latch: " Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-27 11:40 ` [PATCH v1 8/8] seqlock: seqcount latch APIs: Only allow seqcount_latch_t Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] " tip-bot2 for Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 0/5] seqlock: Introduce PREEMPT_RT support Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 1/5] seqlock: seqcount_LOCKTYPE_t: Standardize naming convention Ahmed S. Darwish
2020-08-28 8:18 ` peterz
2020-08-28 8:24 ` Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 2/5] seqlock: Use unique prefix for seqcount_t property accessors Ahmed S. Darwish
2020-08-28 8:27 ` peterz
2020-08-28 8:59 ` Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 3/5] seqlock: seqcount_t: Implement all read APIs as statement expressions Ahmed S. Darwish
2020-08-28 8:30 ` peterz
2020-08-28 8:37 ` Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 4/5] seqlock: seqcount_LOCKTYPE_t: Introduce PREEMPT_RT support Ahmed S. Darwish
2020-08-28 8:57 ` peterz
2020-08-28 8:59 ` peterz
2020-08-28 9:31 ` Ahmed S. Darwish
2020-08-28 14:36 ` Ahmed S. Darwish
2020-08-28 1:07 ` [PATCH v1 5/5] seqlock: PREEMPT_RT: Do not starve seqlock_t writers Ahmed S. Darwish
2020-09-04 6:52 ` [PATCH v1 0/5] seqlock: Introduce PREEMPT_RT support peterz
2020-09-04 7:30 ` Ahmed S. Darwish
2020-09-10 15:08 ` [tip: locking/core] seqlock: seqcount_LOCKNAME_t: " tip-bot2 for Ahmed S. Darwish
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