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From:   Peter Oskolkov <posk@google.com>
Date:   Mon, 24 Jan 2022 09:06:29 -0800
Message-ID: <CAPNVh5ftS=3+ip0Di=tT4Os+602Dwc4s3bbeim91nFh5iF+Vdg@mail.gmail.com>
Subject: Re: [RFC][PATCH v2 5/5] sched: User Mode Concurency Groups
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     mingo@redhat.com, tglx@linutronix.de, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-api@vger.kernel.org, x86@kernel.org,
        pjt@google.com, avagin@google.com, jannh@google.com,
        tdelisle@uwaterloo.ca, mark.rutland@arm.com, posk@posk.io
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On Mon, Jan 24, 2022 at 8:44 AM Peter Zijlstra <peterz@infradead.org> wrote:

[...]
> >
> > Oh how I hate signals... this can get scribbled by a syscall/fault from
> > sigcontext :/
> >
> > Maybe I can recover the timo argument from the original syscall
> > pt_regs.. let me try.

I don't think we need to do anything special with timeouts if a signal
happens - just normally return -EINTR (after a resume from a server)
and let the userspace figure things out.

Alternatively, in my version of the patchset UMCG tasks ignore
non-fatal signals. :)

[...]