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From:   Andrei Vagin <avagin@gmail.com>
Date:   Mon, 5 Dec 2022 22:52:48 -0800
Message-ID: <CANaxB-x=QMiTMf6-RCy1Vs8gyU=idqeK419y=BMpfeQ1oHL4XA@mail.gmail.com>
Subject: Re: [PATCH 0/5 v3] seccomp: add the synchronous mode for seccomp_unotify
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>
Cc:     Andrei Vagin <avagin@google.com>,
        Christian Brauner <brauner@kernel.org>,
        linux-kernel@vger.kernel.org,
        Andy Lutomirski <luto@amacapital.net>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Peter Oskolkov <posk@google.com>,
        Tycho Andersen <tycho@tycho.pizza>,
        Will Drewry <wad@chromium.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Kees Cook <keescook@chromium.org>
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On Mon, Nov 21, 2022 at 11:52 PM Andrei Vagin <avagin@gmail.com> wrote:
>
> On Fri, Nov 18, 2022 at 2:38 PM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Thu, Nov 10, 2022 at 11:31:49PM -0800, Andrei Vagin wrote:
> > > From: Andrei Vagin <avagin@gmail.com>
> > >
> > > seccomp_unotify allows more privileged processes do actions on behalf
> > > of less privileged processes.
> > >
> > > In many cases, the workflow is fully synchronous. It means a target
> > > process triggers a system call and passes controls to a supervisor
> > > process that handles the system call and returns controls back to the
> > > target process. In this context, "synchronous" means that only one
> > > process is running and another one is waiting.
> > >
> > > The new WF_CURRENT_CPU flag advises the scheduler to move the wakee t=
o
> > > the current CPU. For such synchronous workflows, it makes context
> > > switches a few times faster.
> > >
> > > Right now, each interaction takes 12=E7=9B=9C. With this patch, it ta=
kes about
> > > 3=E7=9B=9C.
> > >
> > > v2: clean up the first patch and add the test.
> > > v3: update commit messages and a few fixes suggested by Kees Cook.
> >
> > Thanks for the update! If I can get Acks from the sched folks, I think
> > this looks good to take.
>
> Peter, Ingo, could you take a look at this series?

Friendly ping

>
> Thanks,
> Andrei