From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Julia Cartwright <julia@ni.com>,
Daniel Wagner <daniel.wagner@siemens.com>,
tom.zanussi@linux.intel.com, stable-rt@vger.kernel.org
Subject: [PATCH RT 07/22] seqlock: provide the same ordering semantics as mainline
Date: Wed, 05 Sep 2018 08:28:01 -0400 [thread overview]
Message-ID: <20180905122835.375399705@goodmis.org> (raw)
In-Reply-To: 20180905122754.443196118@goodmis.org
4.14.63-rt41-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Julia Cartwright <julia@ni.com>
[ Upstream commit afa4c06b89a3c0fb7784ff900ccd707bef519cb7 ]
The mainline implementation of read_seqbegin() orders prior loads w.r.t.
the read-side critical section. Fixup the RT writer-boosting
implementation to provide the same guarantee.
Also, while we're here, update the usage of ACCESS_ONCE() to use
READ_ONCE().
Fixes: e69f15cf77c23 ("seqlock: Prevent rt starvation")
Cc: stable-rt@vger.kernel.org
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/seqlock.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index a59751276b94..107079a2d7ed 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -462,6 +462,7 @@ static inline unsigned read_seqbegin(seqlock_t *sl)
spin_unlock_wait(&sl->lock);
goto repeat;
}
+ smp_rmb();
return ret;
}
#endif
--
2.18.0
next prev parent reply other threads:[~2018-09-05 12:30 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 12:27 [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 01/22] sched/fair: Fix CFS bandwidth control lockdep DEADLOCK report Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 02/22] locallock: provide {get,put}_locked_ptr() variants Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 03/22] squashfs: make use of local lock in multi_cpu decompressor Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 04/22] PM / suspend: Prevent might sleep splats (updated) Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 05/22] PM / wakeup: Make events_lock a RAW_SPINLOCK Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 06/22] PM / s2idle: Make s2idle_wait_head swait based Steven Rostedt
2018-09-05 12:28 ` Steven Rostedt [this message]
2018-09-05 12:28 ` [PATCH RT 08/22] Revert "x86: UV: raw_spinlock conversion" Steven Rostedt
2018-09-06 7:35 ` Sebastian Andrzej Siewior
2018-09-06 8:38 ` Mike Galbraith
2018-09-06 12:58 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 09/22] Revert "timer: delay waking softirqs from the jiffy tick" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 10/22] irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 11/22] irqchip/gic-v3-its: Move ITS ->pend_page allocation into an early CPU up hook Steven Rostedt
2018-09-06 7:40 ` Sebastian Andrzej Siewior
2018-09-07 19:28 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 12/22] sched/migrate_disable: fallback to preempt_disable() instead barrier() Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 13/22] x86/ioapic: Dont let setaffinity unmask threaded EOI interrupt too early Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 14/22] efi: Allow efi=runtime Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 15/22] efi: Disable runtime services on RT Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 16/22] crypto: cryptd - add a lock instead preempt_disable/local_bh_disable Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 17/22] crypto: scompress - serialize RT percpu scratch buffer access with a local lock Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 18/22] sched/core: Avoid __schedule() being called twice in a row Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 19/22] Revert "arm64/xen: Make XEN depend on !RT" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 20/22] sched: Allow pinned user tasks to be awakened to the CPU they pinned Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 22/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
[not found] ` <20180905122837.830614967@goodmis.org>
2018-09-05 12:34 ` [PATCH RT 21/22] Drivers: hv: vmbus: include header for get_irq_regs() Steven Rostedt
2018-09-06 7:54 ` [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Sebastian Andrzej Siewior
2018-09-06 16:43 ` Steven Rostedt
2018-09-06 19:30 ` Sebastian Andrzej Siewior
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