From: Richard Henderson <rth@twiddle.net>
To: "Emilio G. Cota" <cota@braap.org>,
QEMU Developers <qemu-devel@nongnu.org>,
MTTCG Devel <mttcg@greensocs.com>
Cc: "Alex Bennée" <alex.bennee@linaro.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Peter Crosthwaite" <crosthwaite.peter@gmail.com>,
"Peter Maydell" <peter.maydell@linaro.org>,
"Sergey Fedorov" <serge.fdrv@gmail.com>
Subject: Re: [Qemu-devel] [PATCH v2 08/13] qemu-thread: optimize spin_lock for uncontended locks
Date: Fri, 8 Apr 2016 11:40:25 -0700 [thread overview]
Message-ID: <5707FB19.2020709@twiddle.net> (raw)
In-Reply-To: <1460050358-25025-9-git-send-email-cota@braap.org>
On 04/07/2016 10:32 AM, Emilio G. Cota wrote:
> static inline void qemu_spin_lock(QemuSpin *spin)
> {
> - do {
> + while (atomic_xchg(&spin->value, true)) {
> while (atomic_read(&spin->value)) {
> cpu_relax();
> }
> - } while (atomic_xchg(&spin->value, true));
> + }
> }
And merge this one as well, please. It's a good improvement, but there's
little point to keeping these separate.
r~
next prev parent reply other threads:[~2016-04-08 18:40 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-07 17:32 [Qemu-devel] [PATCH v2 00/10] tb hash improvements Emilio G. Cota
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 02/13] compiler.h: add QEMU_ALIGNED() to enforce struct alignment Emilio G. Cota
2016-04-08 18:26 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 03/13] seqlock: remove optional mutex Emilio G. Cota
2016-04-08 18:26 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 04/13] seqlock: rename write_lock/unlock to write_begin/end Emilio G. Cota
2016-04-08 18:27 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 05/13] include/processor.h: define cpu_relax() Emilio G. Cota
2016-04-08 18:33 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 06/13] qemu-thread: add simple test-and-set spinlock Emilio G. Cota
2016-04-08 13:02 ` Alex Bennée
2016-04-08 18:38 ` Richard Henderson
2016-04-08 21:24 ` Alex Bennée
2016-04-08 21:26 ` Paolo Bonzini
2016-04-08 21:31 ` Richard Henderson
2016-04-08 21:35 ` Sergey Fedorov
2016-04-08 18:35 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 07/13] qemu-thread: call cpu_relax() while spinning Emilio G. Cota
2016-04-08 18:39 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 08/13] qemu-thread: optimize spin_lock for uncontended locks Emilio G. Cota
2016-04-08 18:40 ` Richard Henderson [this message]
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 09/13] exec: add tb_hash_func5, derived from xxhash Emilio G. Cota
2016-04-08 18:45 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 10/13] tb hash: hash phys_pc, pc, and flags with xxhash Emilio G. Cota
2016-04-08 18:48 ` Richard Henderson
2016-04-07 17:32 ` [Qemu-devel] [PATCH v2 12/13] qht: add test program Emilio G. Cota
2016-04-08 12:41 ` [Qemu-devel] [PATCH v2 00/10] tb hash improvements Alex Bennée
[not found] ` <1460050358-25025-2-git-send-email-cota@braap.org>
2016-04-08 18:25 ` [Qemu-devel] [PATCH v2 01/13] translate-all: add missing fold of tb_ctx into tcg_ctx Richard Henderson
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