From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Waiman.Long@hp.com, mingo@redhat.com
Subject: Re: [PATCH 6/9] locking/qrwlock: allow architectures to hook in to contended paths
Date: Wed, 8 Jul 2015 12:06:57 +0200 [thread overview]
Message-ID: <20150708100657.GD3644@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1436289865-2331-7-git-send-email-will.deacon@arm.com>
On Tue, Jul 07, 2015 at 06:24:22PM +0100, Will Deacon wrote:
> When contended, architectures may be able to reduce the polling overhead
> in ways which aren't expressible using a simple relax() primitive.
>
> This patch allows architectures to override the use of
> cpu_relax_lowlatency() in the qrwlock code and also implement their own
> unlock macros in case explicit signalling is required to wake up a
> `relaxed' CPU spinning on an unlock event.
No real objection, but could you do this _after_ you've converted
AARGH64 to use the normal qrwlock, such that you can show the benefit
with numbers?
WARNING: multiple messages have this Message-ID (diff)
From: peterz@infradead.org (Peter Zijlstra)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 6/9] locking/qrwlock: allow architectures to hook in to contended paths
Date: Wed, 8 Jul 2015 12:06:57 +0200 [thread overview]
Message-ID: <20150708100657.GD3644@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1436289865-2331-7-git-send-email-will.deacon@arm.com>
On Tue, Jul 07, 2015 at 06:24:22PM +0100, Will Deacon wrote:
> When contended, architectures may be able to reduce the polling overhead
> in ways which aren't expressible using a simple relax() primitive.
>
> This patch allows architectures to override the use of
> cpu_relax_lowlatency() in the qrwlock code and also implement their own
> unlock macros in case explicit signalling is required to wake up a
> `relaxed' CPU spinning on an unlock event.
No real objection, but could you do this _after_ you've converted
AARGH64 to use the normal qrwlock, such that you can show the benefit
with numbers?
next prev parent reply other threads:[~2015-07-08 10:07 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-07 17:24 [PATCH 0/9] locking/qrwlock: get qrwlocks up and running on arm64 Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-07 17:24 ` [PATCH 1/9] locking/qrwlock: include <linux/spinlock.h> for arch_spin_{lock,unlock} Will Deacon
2015-07-07 17:24 ` [PATCH 1/9] locking/qrwlock: include <linux/spinlock.h> for arch_spin_{lock, unlock} Will Deacon
2015-07-07 17:24 ` [PATCH 2/9] locking/qrwlock: avoid redundant atomic_add_return on read_lock_slowpath Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-07 17:51 ` Waiman Long
2015-07-07 17:51 ` Waiman Long
2015-07-07 18:19 ` Will Deacon
2015-07-07 18:19 ` Will Deacon
2015-07-07 19:28 ` Waiman Long
2015-07-07 19:28 ` Waiman Long
2015-07-08 9:59 ` Peter Zijlstra
2015-07-08 9:59 ` Peter Zijlstra
2015-07-08 13:37 ` Will Deacon
2015-07-08 13:37 ` Will Deacon
2015-07-07 21:30 ` Peter Zijlstra
2015-07-07 21:30 ` Peter Zijlstra
2015-07-07 17:24 ` [PATCH 3/9] locking/qrwlock: tidy up rspin_until_writer_unlock Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-07 17:24 ` [PATCH 4/9] locking/qrwlock: implement queue_write_unlock using smp_store_release Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-08 10:00 ` Peter Zijlstra
2015-07-08 10:00 ` Peter Zijlstra
2015-07-07 17:24 ` [PATCH 5/9] locking/qrwlock: remove redundant cmpxchg barriers on writer slow-path Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-08 10:05 ` Peter Zijlstra
2015-07-08 10:05 ` Peter Zijlstra
2015-07-08 13:34 ` Will Deacon
2015-07-08 13:34 ` Will Deacon
2015-07-07 17:24 ` [PATCH 6/9] locking/qrwlock: allow architectures to hook in to contended paths Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-08 10:06 ` Peter Zijlstra [this message]
2015-07-08 10:06 ` Peter Zijlstra
2015-07-08 13:35 ` Will Deacon
2015-07-08 13:35 ` Will Deacon
2015-07-07 17:24 ` [PATCH 7/9] locking/qrwlock: expose internal lock structure in qrwlock definition Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-07 17:24 ` [PATCH 8/9] arm64: cmpxchg: implement cmpxchg_relaxed Will Deacon
2015-07-07 17:24 ` Will Deacon
2015-07-07 17:24 ` [PATCH 9/9] arm64: locking: replace read/write locks with generic qrwlock code Will Deacon
2015-07-07 17:24 ` Will Deacon
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