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Date:   Thu, 20 Oct 2022 17:48:25 -0700
From:   Andrei Vagin <avagin@gmail.com>
To:     Kees Cook <kees@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        Andy Lutomirski <luto@amacapital.net>,
        Christian Brauner <brauner@kernel.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Peter Oskolkov <posk@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Tycho Andersen <tycho@tycho.pizza>,
        Will Drewry <wad@chromium.org>,
        Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH 2/5] sched: add WF_CURRENT_CPU and externise ttwu
Message-ID: <Y1HsWddXgnYNH0aa@gmail.com>
References: <20221020011048.156415-1-avagin@gmail.com>
 <20221020011048.156415-3-avagin@gmail.com>
 <714DD165-E237-4599-9EE8-477B01AB4365@kernel.org>
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On Wed, Oct 19, 2022 at 09:54:15PM -0700, Kees Cook wrote:
> On October 19, 2022 6:10:45 PM PDT, Andrei Vagin <avagin@gmail.com> wrote:
> >From: Peter Oskolkov <posk@google.com>
> >
> >Add WF_CURRENT_CPU wake flag that advices the scheduler to
> >move the wakee to the current CPU. This is useful for fast on-CPU
> >context switching use cases such as UMCG.
> 
> UMCG is https://lwn.net/Articles/879398/ ?
> 

Yes, this is it. https://lkml.org/lkml/2021/11/4/830 is the most recent
version that I've seen.

> >In addition, make ttwu external rather than static so that
> >the flag could be passed to it from outside of sched/core.c.
> >
> >Signed-off-by: Peter Oskolkov <posk@google.com>
> >Signed-off-by: Andrei Vagin <avagin@gmail.com>
> >---
> > kernel/sched/core.c  |  3 +--
> > kernel/sched/fair.c  |  4 ++++
> > kernel/sched/sched.h | 13 ++++++++-----
> > 3 files changed, 13 insertions(+), 7 deletions(-)
> 
> This would need an Ack from the sched maintainers...