From: Peter Zijlstra <peterz@infradead.org>
To: Peter Oskolkov <posk@posk.io>
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, posk@google.com, avagin@google.com,
jannh@google.com, tdelisle@uwaterloo.ca
Subject: Re: [RFC][PATCH 3/3] sched: User Mode Concurency Groups
Date: Fri, 14 Jan 2022 16:16:53 +0100 [thread overview]
Message-ID: <YeGT5dvA8KFeW+69@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <YeGEM7TP3tekBVEh@hirez.programming.kicks-ass.net>
On Fri, Jan 14, 2022 at 03:09:55PM +0100, Peter Zijlstra wrote:
> > I think the assumption is based on the idea that a process
> > using UMCG will get affined to N CPUs, will have N servers and
> > a number of workers, and they will all happily cooperate and not
> > get any extra threads running.
> >
> > Of course the pretty picture was not completely true, as the unblocked
> > tasks do consume extra threads in the kernel, though never in the
> > userspace.
>
> Right, there is some unmanaged time anyway.
Also, since we force wake to the same CPU, and overlapping runtime is
'short', they should all stick to the same CPU, even if we don't pin.
next prev parent reply other threads:[~2022-01-14 15:17 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-14 20:44 [RFC][PATCH 0/3] sched: User Managed Concurrency Groups Peter Zijlstra
2021-12-14 20:44 ` [RFC][PATCH 1/3] sched/umcg: add WF_CURRENT_CPU and externise ttwu Peter Zijlstra
2021-12-14 20:44 ` [RFC][PATCH 2/3] x86/uaccess: Implement unsafe_try_cmpxchg_user() Peter Zijlstra
2021-12-20 17:30 ` Sean Christopherson
2021-12-21 11:17 ` Peter Zijlstra
2021-12-14 20:44 ` [RFC][PATCH 3/3] sched: User Mode Concurency Groups Peter Zijlstra
2021-12-21 17:19 ` Peter Oskolkov
2022-01-14 14:09 ` Peter Zijlstra
2022-01-14 15:16 ` Peter Zijlstra [this message]
2022-01-14 17:15 ` Peter Zijlstra
2022-01-17 11:35 ` Peter Zijlstra
2022-01-17 12:22 ` Peter Zijlstra
2022-01-17 12:12 ` Peter Zijlstra
2022-01-18 10:09 ` Peter Zijlstra
2022-01-18 18:19 ` Peter Oskolkov
2022-01-19 8:47 ` Peter Zijlstra
2022-01-19 17:33 ` Peter Oskolkov
2022-01-19 8:51 ` Peter Zijlstra
2022-01-19 8:59 ` Peter Zijlstra
2022-01-19 17:52 ` Peter Oskolkov
2022-01-20 10:37 ` Peter Zijlstra
2022-01-17 13:04 ` Peter Zijlstra
2021-12-24 11:27 ` Peter Zijlstra
2021-12-14 21:00 ` [RFC][PATCH 0/3] sched: User Managed Concurrency Groups Peter Zijlstra
2021-12-15 3:46 ` Peter Oskolkov
2021-12-15 10:06 ` Peter Zijlstra
2021-12-15 13:03 ` Peter Zijlstra
2021-12-15 17:56 ` Peter Oskolkov
2021-12-15 18:18 ` Peter Zijlstra
2021-12-15 19:49 ` Peter Oskolkov
2021-12-15 22:25 ` Peter Zijlstra
2021-12-15 23:26 ` Peter Oskolkov
2021-12-16 13:23 ` Thomas Gleixner
2021-12-15 18:25 ` Peter Zijlstra
2021-12-15 21:04 ` Peter Oskolkov
2021-12-15 23:16 ` Peter Zijlstra
2021-12-15 23:31 ` Peter Oskolkov
2021-12-15 10:44 ` Peter Zijlstra
2021-12-15 13:49 ` Matthew Wilcox
2021-12-15 17:54 ` Peter Zijlstra
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