From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <waiman.long@hp.com>
Cc: linux-arch@vger.kernel.org, Rik van Riel <riel@redhat.com>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
Gleb Natapov <gleb@redhat.com>,
kvm@vger.kernel.org,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
Scott J Norton <scott.norton@hp.com>,
x86@kernel.org, Paolo Bonzini <paolo.bonzini@gmail.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Ingo Molnar <mingo@redhat.com>, Chegu Vinod <chegu_vinod@hp.com>,
David Vrabel <david.vrabel@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
xen-devel@lists.xenproject.org,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v9 05/19] qspinlock: Optimize for smaller NR_CPUS
Date: Fri, 18 Apr 2014 09:46:16 +0200 [thread overview]
Message-ID: <20140418074616.GB13517@gmail.com> (raw)
In-Reply-To: <53504C4E.8060800@hp.com>
* Waiman Long <waiman.long@hp.com> wrote:
> On 04/17/2014 11:58 AM, Peter Zijlstra wrote:
> >On Thu, Apr 17, 2014 at 11:03:57AM -0400, Waiman Long wrote:
> >>+static __always_inline void
> >>+clear_pending_set_locked(struct qspinlock *lock, u32 val)
> >>+{
> >>+ struct __qspinlock *l = (void *)lock;
> >>+
> >>+ ACCESS_ONCE(l->locked_pending) = 1;
> >>+}
> >>@@ -157,8 +251,13 @@ static inline int trylock_pending(struct qspinlock *lock, u32 *pval)
> >> * we're pending, wait for the owner to go away.
> >> *
> >> * *,1,1 -> *,1,0
> >>+ *
> >>+ * this wait loop must be a load-acquire such that we match the
> >>+ * store-release that clears the locked bit and create lock
> >>+ * sequentiality; this because not all try_clear_pending_set_locked()
> >>+ * implementations imply full barriers.
> >You renamed the function referred in the above comment.
> >
>
> Sorry, will fix the comments.
I suggest not renaming the function instead.
try_clear_pending_set_locked() tells the intent in a clearer fashion.
Thanks,
Ingo
WARNING: multiple messages have this Message-ID (diff)
From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <waiman.long@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
linux-arch@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
xen-devel@lists.xenproject.org, kvm@vger.kernel.org,
Paolo Bonzini <paolo.bonzini@gmail.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
David Vrabel <david.vrabel@citrix.com>,
Oleg Nesterov <oleg@redhat.com>, Gleb Natapov <gleb@redhat.com>,
Scott J Norton <scott.norton@hp.com>,
Chegu Vinod <chegu_vinod@hp.com>
Subject: Re: [PATCH v9 05/19] qspinlock: Optimize for smaller NR_CPUS
Date: Fri, 18 Apr 2014 09:46:16 +0200 [thread overview]
Message-ID: <20140418074616.GB13517@gmail.com> (raw)
Message-ID: <20140418074616.0T8mj-sXi-QvixdUkIyYIQNknaI2AxfS3JR0DhzjHck@z> (raw)
In-Reply-To: <53504C4E.8060800@hp.com>
* Waiman Long <waiman.long@hp.com> wrote:
> On 04/17/2014 11:58 AM, Peter Zijlstra wrote:
> >On Thu, Apr 17, 2014 at 11:03:57AM -0400, Waiman Long wrote:
> >>+static __always_inline void
> >>+clear_pending_set_locked(struct qspinlock *lock, u32 val)
> >>+{
> >>+ struct __qspinlock *l = (void *)lock;
> >>+
> >>+ ACCESS_ONCE(l->locked_pending) = 1;
> >>+}
> >>@@ -157,8 +251,13 @@ static inline int trylock_pending(struct qspinlock *lock, u32 *pval)
> >> * we're pending, wait for the owner to go away.
> >> *
> >> * *,1,1 -> *,1,0
> >>+ *
> >>+ * this wait loop must be a load-acquire such that we match the
> >>+ * store-release that clears the locked bit and create lock
> >>+ * sequentiality; this because not all try_clear_pending_set_locked()
> >>+ * implementations imply full barriers.
> >You renamed the function referred in the above comment.
> >
>
> Sorry, will fix the comments.
I suggest not renaming the function instead.
try_clear_pending_set_locked() tells the intent in a clearer fashion.
Thanks,
Ingo
next prev parent reply other threads:[~2014-04-18 7:46 UTC|newest]
Thread overview: 211+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-17 15:03 [PATCH v9 00/19] qspinlock: a 4-byte queue spinlock with PV support Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` [PATCH v9 01/19] qspinlock: A simple generic 4-byte queue spinlock Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` [PATCH v9 02/19] qspinlock, x86: Enable x86-64 to use " Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` [PATCH v9 03/19] qspinlock: Add pending bit Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:42 ` Peter Zijlstra
2014-04-17 15:42 ` Peter Zijlstra
2014-04-17 15:42 ` Peter Zijlstra
2014-04-17 21:20 ` Waiman Long
2014-04-18 8:13 ` Peter Zijlstra
2014-04-18 8:13 ` Peter Zijlstra
2014-04-18 17:07 ` Waiman Long
2014-04-18 17:07 ` Waiman Long
2014-04-18 17:07 ` Waiman Long
2014-04-18 8:13 ` Peter Zijlstra
2014-04-17 21:20 ` Waiman Long
2014-04-17 21:20 ` Waiman Long
2014-04-18 7:42 ` Ingo Molnar
2014-04-18 7:42 ` Ingo Molnar
2014-04-18 7:42 ` Ingo Molnar
2014-04-18 16:23 ` Waiman Long
2014-04-18 16:23 ` Waiman Long
2014-04-18 16:35 ` Konrad Rzeszutek Wilk
2014-04-18 16:35 ` Konrad Rzeszutek Wilk
2014-04-18 16:35 ` Konrad Rzeszutek Wilk
2014-04-18 18:12 ` Waiman Long
2014-04-18 18:12 ` Waiman Long
2014-04-18 18:12 ` Waiman Long
2014-04-18 16:23 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` [PATCH v9 04/19] qspinlock: Extract out the exchange of tail code word Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:49 ` Peter Zijlstra
2014-04-17 15:49 ` Peter Zijlstra
2014-04-17 21:28 ` Waiman Long
2014-04-17 21:28 ` Waiman Long
2014-04-17 21:28 ` Waiman Long
2014-04-18 8:15 ` Peter Zijlstra
2014-04-18 8:15 ` Peter Zijlstra
2014-04-18 17:32 ` Waiman Long
2014-04-18 17:32 ` Waiman Long
2014-04-18 17:32 ` Waiman Long
2014-04-18 17:53 ` Peter Zijlstra
2014-04-18 17:53 ` Peter Zijlstra
2014-04-18 18:13 ` Waiman Long
2014-04-18 18:13 ` Waiman Long
2014-04-18 18:13 ` Waiman Long
2014-04-18 17:53 ` Peter Zijlstra
2014-04-18 8:15 ` Peter Zijlstra
2014-04-17 15:49 ` Peter Zijlstra
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` [PATCH v9 05/19] qspinlock: Optimize for smaller NR_CPUS Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:50 ` Peter Zijlstra
2014-04-17 15:50 ` Peter Zijlstra
2014-04-17 21:29 ` Waiman Long
2014-04-17 21:29 ` Waiman Long
2014-04-17 21:29 ` Waiman Long
2014-04-17 15:50 ` Peter Zijlstra
2014-04-17 15:51 ` Peter Zijlstra
2014-04-17 15:51 ` Peter Zijlstra
2014-04-17 21:33 ` Waiman Long
2014-04-17 21:33 ` Waiman Long
2014-04-17 21:33 ` Waiman Long
2014-04-17 15:51 ` Peter Zijlstra
2014-04-17 15:56 ` Peter Zijlstra
2014-04-17 15:56 ` Peter Zijlstra
2014-04-17 21:46 ` Waiman Long
2014-04-17 21:46 ` Waiman Long
2014-04-18 8:27 ` Peter Zijlstra
2014-04-18 8:27 ` Peter Zijlstra
2014-04-18 8:27 ` Peter Zijlstra
2014-04-18 17:52 ` Waiman Long
2014-04-18 17:52 ` Waiman Long
2014-04-18 19:05 ` Peter Zijlstra
2014-04-18 19:05 ` Peter Zijlstra
2014-04-18 21:40 ` Waiman Long
2014-04-18 21:40 ` Waiman Long
2014-04-23 14:23 ` Waiman Long
2014-04-23 14:23 ` Waiman Long
2014-04-23 14:56 ` Konrad Rzeszutek Wilk
2014-04-23 14:56 ` Konrad Rzeszutek Wilk
2014-04-23 14:56 ` Konrad Rzeszutek Wilk
2014-04-23 17:43 ` Waiman Long
2014-04-23 17:43 ` Waiman Long
2014-04-23 17:55 ` Konrad Rzeszutek Wilk
2014-04-23 17:55 ` Konrad Rzeszutek Wilk
2014-04-23 17:55 ` Konrad Rzeszutek Wilk
2014-04-23 22:24 ` Waiman Long
2014-04-23 22:24 ` Waiman Long
2014-04-23 23:48 ` Waiman Long
2014-04-23 23:48 ` Waiman Long
2014-04-23 23:48 ` Waiman Long
2014-04-23 22:24 ` Waiman Long
2014-04-23 17:43 ` Waiman Long
2014-04-23 14:23 ` Waiman Long
2014-04-18 21:40 ` Waiman Long
2014-04-18 19:05 ` Peter Zijlstra
2014-04-18 17:52 ` Waiman Long
2014-04-17 21:46 ` Waiman Long
2014-04-17 15:56 ` Peter Zijlstra
2014-04-17 15:58 ` Peter Zijlstra
2014-04-17 15:58 ` Peter Zijlstra
2014-04-17 21:49 ` Waiman Long
2014-04-17 21:49 ` Waiman Long
2014-04-17 21:49 ` Waiman Long
2014-04-18 7:46 ` Ingo Molnar [this message]
2014-04-18 7:46 ` Ingo Molnar
2014-04-18 16:26 ` Waiman Long
2014-04-18 16:26 ` Waiman Long
2014-04-19 9:24 ` Ingo Molnar
2014-04-19 9:24 ` Ingo Molnar
2014-04-19 9:24 ` Ingo Molnar
2014-04-18 16:26 ` Waiman Long
2014-04-18 7:46 ` Ingo Molnar
2014-04-17 15:58 ` Peter Zijlstra
2014-04-17 15:03 ` [PATCH v9 06/19] qspinlock: prolong the stay in the pending bit path Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 16:36 ` Peter Zijlstra
2014-04-17 16:36 ` Peter Zijlstra
2014-04-17 16:36 ` Peter Zijlstra
2014-04-18 1:46 ` Waiman Long
2014-04-18 1:46 ` Waiman Long
2014-04-18 1:46 ` Waiman Long
2014-04-18 8:33 ` Peter Zijlstra
2014-04-18 8:33 ` Peter Zijlstra
2014-04-18 18:07 ` Waiman Long
2014-04-18 18:07 ` Waiman Long
2014-04-18 18:07 ` Waiman Long
2014-04-18 8:33 ` Peter Zijlstra
2014-04-17 15:03 ` [PATCH v9 07/19] qspinlock: Use a simple write to grab the lock, if applicable Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 15:03 ` Waiman Long
2014-04-17 16:54 ` Peter Zijlstra
2014-04-17 16:54 ` Peter Zijlstra
2014-04-17 16:54 ` Peter Zijlstra
2014-04-17 15:04 ` [PATCH v9 08/19] qspinlock: Make a new qnode structure to support virtualization Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 09/19] qspinlock: Prepare for unfair lock support Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 10/19] qspinlock, x86: Allow unfair spinlock in a virtual guest Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 11/19] qspinlock: Split the MCS queuing code into a separate slowerpath Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 12/19] unfair qspinlock: Variable frequency lock stealing mechanism Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 13/19] unfair qspinlock: Enable lock stealing in lock waiters Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 14/19] pvqspinlock, x86: Rename paravirt_ticketlocks_enabled Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 15/19] pvqspinlock, x86: Add PV data structure & methods Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 16/19] pvqspinlock: Enable coexistence with the unfair lock Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 17/19] pvqspinlock: Add qspinlock para-virtualization support Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 18/19] pvqspinlock, x86: Enable PV qspinlock PV for KVM Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` [PATCH v9 19/19] pvqspinlock, x86: Enable PV qspinlock for XEN Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 15:04 ` Waiman Long
2014-04-17 17:23 ` [PATCH v9 00/19] qspinlock: a 4-byte queue spinlock with PV support Konrad Rzeszutek Wilk
2014-04-17 17:23 ` Konrad Rzeszutek Wilk
2014-04-17 17:40 ` Raghavendra K T
2014-04-17 17:40 ` Raghavendra K T
2014-04-18 1:50 ` Waiman Long
2014-04-18 1:50 ` Waiman Long
2014-04-18 1:50 ` Waiman Long
2014-04-17 17:40 ` Raghavendra K T
2014-04-18 1:48 ` Waiman Long
2014-04-18 1:48 ` Waiman Long
2014-04-18 13:18 ` Konrad Rzeszutek Wilk
2014-04-18 13:18 ` Konrad Rzeszutek Wilk
2014-04-18 17:05 ` Waiman Long
2014-04-18 17:05 ` Waiman Long
2014-04-18 17:05 ` Waiman Long
2014-04-18 13:18 ` Konrad Rzeszutek Wilk
2014-04-18 1:48 ` Waiman Long
2014-04-17 17:23 ` Konrad Rzeszutek Wilk
2014-04-27 18:09 ` Raghavendra K T
2014-04-27 18:09 ` Raghavendra K T
2014-05-07 15:00 ` Waiman Long
2014-05-07 15:00 ` Waiman Long
2014-05-07 15:00 ` Waiman Long
2014-04-27 18:09 ` Raghavendra K T
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