From: "Christoph Lameter (Ampere)" <cl@gentwo.org>
To: Ankur Arora <ankur.a.arora@oracle.com>
Cc: linux-pm@vger.kernel.org, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
will@kernel.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
hpa@zytor.com, pbonzini@redhat.com, wanpengli@tencent.com,
vkuznets@redhat.com, rafael@kernel.org,
daniel.lezcano@linaro.org, peterz@infradead.org, arnd@arndb.de,
lenb@kernel.org, mark.rutland@arm.com, harisokn@amazon.com,
mtosatti@redhat.com, sudeep.holla@arm.com,
misono.tomohiro@fujitsu.com, joao.m.martins@oracle.com,
boris.ostrovsky@oracle.com, konrad.wilk@oracle.com
Subject: Re: [PATCH v6 02/10] cpuidle: rename ARCH_HAS_CPU_RELAX to ARCH_HAS_OPTIMIZED_POLL
Date: Mon, 5 Aug 2024 16:09:58 -0700 (PDT) [thread overview]
Message-ID: <43b24caf-2ade-e229-21f4-8c01a47f37ed@gentwo.org> (raw)
In-Reply-To: <20240726201332.626395-3-ankur.a.arora@oracle.com>
On Fri, 26 Jul 2024, Ankur Arora wrote:
> However, recent changes in poll_idle() mean that a higher level
> primitive -- smp_cond_load_relaxed() is used for polling. This would
> in-turn use cpu_relax() or an architecture specific implementation.
Maybe explain here that smp_cond_load_relaxed will potentially wait for
important events such as a cacheline changing. Thereby making the busy
poll unnecessary and optimizing power use.
next prev parent reply other threads:[~2024-08-06 1:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-26 20:13 [PATCH v6 00/10] Enable haltpoll on arm64 Ankur Arora
2024-07-26 20:13 ` [PATCH v6 01/10] cpuidle/poll_state: poll via smp_cond_load_relaxed() Ankur Arora
2024-08-05 23:07 ` Christoph Lameter (Ampere)
2024-08-12 22:35 ` Ankur Arora
2024-08-09 5:54 ` Tomohiro Misono (Fujitsu)
2024-08-12 22:36 ` Ankur Arora
2024-07-26 20:13 ` [PATCH v6 02/10] cpuidle: rename ARCH_HAS_CPU_RELAX to ARCH_HAS_OPTIMIZED_POLL Ankur Arora
2024-08-05 23:09 ` Christoph Lameter (Ampere) [this message]
2024-07-26 20:21 ` [PATCH v6 03/10] Kconfig: move ARCH_HAS_OPTIMIZED_POLL to arch/Kconfig Ankur Arora
2024-07-26 20:21 ` [PATCH v6 04/10] cpuidle-haltpoll: define arch_haltpoll_want() Ankur Arora
2024-07-26 20:21 ` [PATCH v6 05/10] governors/haltpoll: drop kvm_para_available() check Ankur Arora
2024-07-26 20:21 ` [PATCH v6 06/10] cpuidle-haltpoll: condition on ARCH_CPUIDLE_HALTPOLL Ankur Arora
2024-07-26 20:21 ` [PATCH v6 07/10] arm64: define TIF_POLLING_NRFLAG Ankur Arora
2024-07-26 20:21 ` [PATCH v6 08/10] arm64: idle: export arch_cpu_idle Ankur Arora
2024-07-26 20:21 ` [PATCH v6 09/10] arm64: support cpuidle-haltpoll Ankur Arora
2024-07-29 17:20 ` Okanovic, Haris
2024-07-29 18:02 ` Ankur Arora
2024-08-13 15:26 ` Okanovic, Haris
2024-08-13 18:56 ` Ankur Arora
2024-08-13 21:14 ` Okanovic, Haris
2024-08-06 1:37 ` maobibo
2024-08-12 22:48 ` Ankur Arora
2024-08-13 0:54 ` maobibo
2024-08-09 6:08 ` Tomohiro Misono (Fujitsu)
2024-07-26 20:21 ` [PATCH v6 10/10] cpuidle/poll_state: limit POLL_IDLE_RELAX_COUNT on arm64 Ankur Arora
2024-08-09 6:02 ` [PATCH v6 00/10] Enable haltpoll " Tomohiro Misono (Fujitsu)
2024-08-12 22:43 ` Ankur Arora
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