From: Andrew Morton <akpm@linux-foundation•org>
To: Ankur Arora <ankur.a.arora@oracle•com>
Cc: linux-kernel@vger•kernel.org, linux-arch@vger•kernel.org,
linux-arm-kernel@lists•infradead.org, linux-pm@vger•kernel.org,
bpf@vger•kernel.org, arnd@arndb•de, catalin.marinas@arm•com,
will@kernel•org, peterz@infradead•org, mark.rutland@arm•com,
harisokn@amazon•com, cl@gentwo•org, ast@kernel•org,
rafael@kernel•org, daniel.lezcano@linaro•org, memxor@gmail•com,
zhenglifeng1@huawei•com, xueshuai@linux•alibaba.com,
rdunlap@infradead•org, david.laight.linux@gmail•com,
joao.m.martins@oracle•com, boris.ostrovsky@oracle•com,
konrad.wilk@oracle•com, ashok.bhat@arm•com
Subject: Re: [PATCH v11 00/14] barrier: Add smp_cond_load_{relaxed,acquire}_timeout()
Date: Thu, 23 Apr 2026 10:16:31 -0700 [thread overview]
Message-ID: <20260423101631.84f26592d629eee46fbde6f8@linux-foundation.org> (raw)
In-Reply-To: <20260408122538.3610871-1-ankur.a.arora@oracle.com>
On Wed, 8 Apr 2026 17:55:24 +0530 Ankur Arora <ankur.a.arora@oracle•com> wrote:
> The core kernel often uses smp_cond_load_{relaxed,acquire}() to spin
> on condition variables with architectural primitives used to avoid
> hammering the relevant cachelines.
>
> ...
>
> Accordingly add two interfaces (with their generic and arm64 specific
> implementations):
>
> smp_cond_load_relaxed_timeout(ptr, cond_expr, time_expr, timeout)
> smp_cond_load_acquire_timeout(ptr, cond_expr, time_expr, timeout)
>
> Also add tif_need_resched_relaxed_wait() which wraps the polling
> pattern and its scheduler specific details in poll_idle().
> In addition add atomic_cond_read_*_timeout(),
Thanks, I'll add this to mm.git's mm-new branch today.
This isn't am MM patchset, but mm-new isn't included in linux-next, and
linux-next isn't presently open for 7.1 material.
After -rc1 I'll move the series into mm.git's mm-nonmm-unstable branch,
where it will get linux-next exposure.
I see that further review/comment has been requested - hopefully this
will happen over the next couple of months, but please do continue to
chase this down if you feel the need.
> Haris Okanovic also saw improvement in real workloads due to the
> cpuidle changes: "observed 4-6% improvements in memcahed, cassandra,
> mysql, and postgresql under certain loads. Other applications likely
> benefit too." [12]
Those are significant improvements. Three years :(
next prev parent reply other threads:[~2026-04-23 17:16 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-08 12:25 [PATCH v11 00/14] barrier: Add smp_cond_load_{relaxed,acquire}_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 01/14] asm-generic: barrier: Add smp_cond_load_relaxed_timeout() Ankur Arora
2026-05-06 7:30 ` Ankur Arora
2026-05-06 8:58 ` David Laight
2026-05-06 20:54 ` Ankur Arora
2026-05-07 9:57 ` David Laight
2026-05-08 6:31 ` Ankur Arora
2026-05-08 8:32 ` David Laight
2026-04-08 12:25 ` [PATCH v11 02/14] arm64: barrier: Support smp_cond_load_relaxed_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 03/14] arm64/delay: move some constants out to a separate header Ankur Arora
2026-04-08 12:25 ` [PATCH v11 04/14] arm64: support WFET in smp_cond_load_relaxed_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 05/14] arm64: rqspinlock: Remove private copy of smp_cond_load_acquire_timewait() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 06/14] asm-generic: barrier: Add smp_cond_load_acquire_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 07/14] atomic: Add atomic_cond_read_*_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 08/14] locking/atomic: scripts: build atomic_long_cond_read_*_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 09/14] bpf/rqspinlock: switch check_timeout() to a clock interface Ankur Arora
2026-04-08 12:25 ` [PATCH v11 10/14] bpf/rqspinlock: Use smp_cond_load_acquire_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 11/14] sched: add need-resched timed wait interface Ankur Arora
2026-04-08 12:25 ` [PATCH v11 12/14] cpuidle/poll_state: Wait for need-resched via tif_need_resched_relaxed_wait() Ankur Arora
2026-04-20 16:57 ` Okanovic, Haris
2026-04-20 17:50 ` Ankur Arora
2026-04-21 7:15 ` Catalin Marinas
2026-04-20 22:12 ` Christoph Lameter (Ampere)
2026-04-08 12:25 ` [PATCH v11 13/14] kunit: enable testing smp_cond_load_relaxed_timeout() Ankur Arora
2026-04-08 12:25 ` [PATCH v11 14/14] kunit: add tests for smp_cond_load_relaxed_timeout() Ankur Arora
2026-05-21 8:30 ` [PATCH v11 1/2] kunit: add tests for smp_cond_load_*_timeout() Ankur Arora
2026-05-21 8:30 ` [PATCH v11 2/2] kunit: add clock tests for smp_cond_load_relaxed_timeout() Ankur Arora
2026-05-21 21:46 ` [PATCH v11 1/2] kunit: add tests for smp_cond_load_*_timeout() Andrew Morton
2026-05-21 21:57 ` Mark Brown
2026-05-22 5:10 ` Ankur Arora
2026-04-23 17:16 ` Andrew Morton [this message]
2026-04-23 19:29 ` [PATCH v11 00/14] barrier: Add smp_cond_load_{relaxed,acquire}_timeout() Ankur Arora
2026-04-24 14:16 ` [PATCH v11 00/14] barrier: Add smp_cond_load_{relaxed, acquire}_timeout() Okanovic, Haris
2026-04-24 14:10 ` Okanovic, Haris
2026-04-24 14:28 ` [PATCH v11 00/14] barrier: Add smp_cond_load_{relaxed,acquire}_timeout() Andrew Morton
2026-04-24 18:10 ` Ankur Arora
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