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>, "Sebastian A. Siewior" <bigeasy@linutronix.de>, "Paul E. McKenney" <paulmck@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, LKML <linux-kernel@vger.kernel.org>, "Ahmed S. Darwish" <a.darwish@linutronix.de> Subject: [PATCH v1 4/5] seqlock: seqcount_LOCKTYPE_t: Introduce PREEMPT_RT support Date: Fri, 28 Aug 2020 03:07:09 +0200 Message-ID: <20200828010710.5407-5-a.darwish@linutronix.de> (raw) In-Reply-To: <20200828010710.5407-1-a.darwish@linutronix.de> Preemption must be disabled before entering a sequence counter write side critical section. Failing to do so, the read side section can preempt the write side section and spin for the entire scheduler tick. If that reader belongs to a real-time scheduling class, it can spin forever and the kernel will livelock. Disabling preemption cannot be done for PREEMPT_RT. It can lead to higher latencies and the write side sections will not be able to acquire locks which become sleeping locks (e.g. spinlock_t). To solve this dilemma, do not disable preemption for seqcount_LOCKTYPE_t writers. Rather, detect if a seqcount_LOCKTYPE_t writer is in progress. If that is the case, acquire then release the associated LOCKTYPE writer serialization lock. This will allow any preempted writer to make progress until the end of its writer serialization lock critical section. Implement this technique for all of PREEMPT_RT sleeping locks. Link: https://lkml.kernel.org/r/159708609435.2571.13948681727529247231.tglx@nanos Link: https://lkml.kernel.org/r/20200519214547.352050-1-a.darwish@linutronix.de References: 55f3560df975 ("seqlock: Extend seqcount API with associated locks") Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> --- include/linux/seqlock.h | 72 +++++++++++++++++++++++++++++++++-------- 1 file changed, 59 insertions(+), 13 deletions(-) diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index d114a9f4e9d9..8d4bf12272ba 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -17,6 +17,7 @@ #include <linux/kcsan-checks.h> #include <linux/lockdep.h> #include <linux/mutex.h> +#include <linux/ww_mutex.h> #include <linux/preempt.h> #include <linux/spinlock.h> @@ -131,7 +132,23 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s) * See Documentation/locking/seqlock.rst */ -#ifdef CONFIG_LOCKDEP +/* + * For PREEMPT_RT, seqcount_LOCKTYPE_t write side critical sections cannot + * disable preemption. It can lead to higher latencies, and the write side + * sections will not be able to acquire locks which become sleeping locks + * (e.g. spinlock_t). + * + * To remain preemptible while avoiding a possible livelock caused by the + * read side preempting the write side, use a different technique: detect + * if a seqcount_LOCKTYPE_t writer is in progress. If that is the case, + * acquire then release the associated LOCKTYPE writer serialization + * lock. This will allow any preempted writer to make progress until the + * end of its writer serialization lock critical section. + * + * This lock-unlock technique must be implemented for all of PREEMPT_RT + * sleeping locks. See Documentation/locking/locktypes.rst + */ +#if defined(CONFIG_LOCKDEP) || defined(CONFIG_PREEMPT_RT) #define __SEQ_LOCK(expr) expr #else #define __SEQ_LOCK(expr) @@ -162,8 +179,10 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s) * @locktype_t: canonical/full LOCKTYPE C data type * @preemptible: preemptibility of above locktype * @lockmember: argument for lockdep_assert_held() + * @lockbase: associated lock release function (prefix only) + * @lock_acquire: associated lock acquisition function (full call) */ -#define SEQCOUNT_LOCKTYPE(locktype, locktype_t, preemptible, lockmember) \ +#define SEQCOUNT_LOCKTYPE(locktype, locktype_t, preemptible, lockmember, lockbase, lock_acquire) \ typedef struct seqcount_##locktype { \ seqcount_t seqcount; \ __SEQ_LOCK(locktype_t *lock); \ @@ -185,7 +204,23 @@ __seqcount_##locktype##_ptr(seqcount_##locktype##_t *s) \ static __always_inline unsigned \ __seqcount_##locktype##_sequence(const seqcount_##locktype##_t *s) \ { \ - return READ_ONCE(s->seqcount.sequence); \ + unsigned seq = READ_ONCE(s->seqcount.sequence); \ + \ + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) \ + return seq; \ + \ + if (preemptible && unlikely(seq & 1)) { \ + __SEQ_LOCK(lock_acquire); \ + __SEQ_LOCK(lockbase##_unlock(s->lock)); \ + \ + /* \ + * Re-read the sequence counter since the (possibly \ + * preempted) writer made progress. \ + */ \ + seq = READ_ONCE(s->seqcount.sequence); \ + } \ + \ + return seq; \ } \ \ static __always_inline bool \ @@ -224,11 +259,13 @@ static inline void __seqcount_t_assert(const seqcount_t *s) lockdep_assert_preemption_disabled(); } -SEQCOUNT_LOCKTYPE(raw_spinlock, raw_spinlock_t, false, s->lock) -SEQCOUNT_LOCKTYPE(spinlock, spinlock_t, false, s->lock) -SEQCOUNT_LOCKTYPE(rwlock, rwlock_t, false, s->lock) -SEQCOUNT_LOCKTYPE(mutex, struct mutex, true, s->lock) -SEQCOUNT_LOCKTYPE(ww_mutex, struct ww_mutex, true, &s->lock->base) +#define __SEQ_RT IS_ENABLED(CONFIG_PREEMPT_RT) + +SEQCOUNT_LOCKTYPE(raw_spinlock, raw_spinlock_t, false, s->lock, raw_spin, raw_spin_lock(s->lock)) +SEQCOUNT_LOCKTYPE(spinlock, spinlock_t, __SEQ_RT, s->lock, spin, spin_lock(s->lock)) +SEQCOUNT_LOCKTYPE(rwlock, rwlock_t, __SEQ_RT, s->lock, read, read_lock(s->lock)) +SEQCOUNT_LOCKTYPE(mutex, struct mutex, true, s->lock, mutex, mutex_lock(s->lock)) +SEQCOUNT_LOCKTYPE(ww_mutex, struct ww_mutex, true, &s->lock->base, ww_mutex, ww_mutex_lock(s->lock, NULL)) /** * SEQCNT_LOCKTYPE_ZERO - static initializer for seqcount_LOCKTYPE_t @@ -408,13 +445,22 @@ static inline int read_seqcount_t_retry(const seqcount_t *s, unsigned start) return __read_seqcount_t_retry(s, start); } +/* + * Automatically disable preemption for seqcount_LOCKTYPE_t writers, if the + * associated lock does not implicitly disable preemption. + * + * Don't do it for PREEMPT_RT. Check __SEQ_LOCK(). + */ +#define __seq_enforce_preemption_protection(s) \ + (!IS_ENABLED(CONFIG_PREEMPT_RT) && __seqcount_lock_preemptible(s)) + /** * raw_write_seqcount_begin() - start a seqcount_t write section w/o lockdep * @s: Pointer to seqcount_t or any of the seqcount_LOCKTYPE_t variants */ #define raw_write_seqcount_begin(s) \ do { \ - if (__seqcount_lock_preemptible(s)) \ + if (__seq_enforce_preemption_protection(s)) \ preempt_disable(); \ \ raw_write_seqcount_t_begin(__seqcount_ptr(s)); \ @@ -435,7 +481,7 @@ static inline void raw_write_seqcount_t_begin(seqcount_t *s) do { \ raw_write_seqcount_t_end(__seqcount_ptr(s)); \ \ - if (__seqcount_lock_preemptible(s)) \ + if (__seq_enforce_preemption_protection(s)) \ preempt_enable(); \ } while (0) @@ -458,7 +504,7 @@ static inline void raw_write_seqcount_t_end(seqcount_t *s) do { \ __seqcount_assert_lock_held(s); \ \ - if (__seqcount_lock_preemptible(s)) \ + if (__seq_enforce_preemption_protection(s)) \ preempt_disable(); \ \ write_seqcount_t_begin_nested(__seqcount_ptr(s), subclass); \ @@ -485,7 +531,7 @@ static inline void write_seqcount_t_begin_nested(seqcount_t *s, int subclass) do { \ __seqcount_assert_lock_held(s); \ \ - if (__seqcount_lock_preemptible(s)) \ + if (__seq_enforce_preemption_protection(s)) \ preempt_disable(); \ \ write_seqcount_t_begin(__seqcount_ptr(s)); \ @@ -506,7 +552,7 @@ static inline void write_seqcount_t_begin(seqcount_t *s) do { \ write_seqcount_t_end(__seqcount_ptr(s)); \ \ - if (__seqcount_lock_preemptible(s)) \ + if (__seq_enforce_preemption_protection(s)) \ preempt_enable(); \ } while (0) -- 2.28.0
next prev parent reply index 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 ` [PATCH v1 09/25] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish 2020-05-22 18:01 ` 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 ` Ahmed S. Darwish [this message] 2020-08-28 8:57 ` [PATCH v1 4/5] seqlock: seqcount_LOCKTYPE_t: Introduce PREEMPT_RT support 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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