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From:   Peter Oskolkov <posk@google.com>
Date:   Thu, 20 May 2021 14:38:33 -0700
Message-ID: <CAPNVh5eV+CtY74_JMv6_Bm5aCVBh_F9hkWLT6v3BT=H0UwodUg@mail.gmail.com>
Subject: Re: [RFC PATCH v0.1 0/9] UMCG early preview/RFC patchset
To:     Jonathan Corbet <corbet@lwn.net>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-api <linux-api@vger.kernel.org>,
        Paul Turner <pjt@google.com>, Ben Segall <bsegall@google.com>,
        Peter Oskolkov <posk@posk.io>,
        Joel Fernandes <joel@joelfernandes.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrei Vagin <avagin@google.com>,
        Jim Newsome <jnewsome@torproject.org>
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On Thu, May 20, 2021 at 2:17 PM Jonathan Corbet <corbet@lwn.net> wrote:
>
> Peter Oskolkov <posk@google.com> writes:
>
> > As indicated earlier in the FUTEX_SWAP patchset:
> >
> > https://lore.kernel.org/lkml/20200722234538.166697-1-posk@posk.io/
> >
> > "Google Fibers" is a userspace scheduling framework
> > used widely and successfully at Google to improve in-process workload
> > isolation and response latencies. We are working on open-sourcing
> > this framework, and UMCG (User-Managed Concurrency Groups) kernel
> > patches are intended as the foundation of this.
>
> So I have to ask...is there *any* documentation out there on what this
> is and how people are supposed to use it?  Shockingly, typing "Google
> fibers" into Google leads to a less than fully joyful outcome...  This
> won't be easy for anybody to review if they have to start by
> reverse-engineering what it's supposed to do.

Hi Jonathan,

There is this Linux Plumbers video: https://www.youtube.com/watch?v=KXuZi9aeGTw
And the pdf: http://pdxplumbers.osuosl.org/2013/ocw//system/presentations/1653/original/LPC%20-%20User%20Threading.pdf

I did not reference them in the patchset because links to sites other
than kernel.org are strongly discouraged... I will definitely add a
documentation patch.

Feel free to reach out to me directly or through this LKML thread if
you have any questions.

Do you think a documentation patch would be useful at this point, as
opposed to a free-form email discussion?

Thanks,
Peter

>
> Thanks,
>
> jon