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From: luca abeni <luca.abeni@santannapisa.it>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: peterz@infradead.org, mingo@redhat.com, rostedt@goodmis.org,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it,
	alessio.balsini@gmail.com, bristot@redhat.com,
	will.deacon@arm.com, andrea.parri@amarulasolutions.com,
	dietmar.eggemann@arm.com, patrick.bellasi@arm.com,
	henrik@austad.us, linux-rt-users@vger.kernel.org
Subject: Re: [RFD/RFC PATCH 0/8] Towards implementing proxy execution
Date: Wed, 10 Oct 2018 12:34:17 +0200	[thread overview]
Message-ID: <20181010123417.26c682ef@luca64> (raw)
In-Reply-To: <20181009092434.26221-1-juri.lelli@redhat.com>

Hi all,

On Tue,  9 Oct 2018 11:24:26 +0200
Juri Lelli <juri.lelli@redhat.com> wrote:

> Hi all,
> 
> Proxy Execution (also goes under several other names) isn't a new
> concept, it has been mentioned already in the past to this community
> (both in email discussions and at conferences [1, 2]), but no actual
> implementation that applies to a fairly recent kernel exists as of
> today (of which I'm aware of at least - happy to be proven wrong).
> 
> Very broadly speaking, more info below, proxy execution enables a task
> to run using the context of some other task that is "willing" to
> participate in the mechanism, as this helps both tasks to improve
> performance (w.r.t. the latter task not participating to proxy
> execution).

First of all, thanks to Juri for working on this!

I am looking at the patchset, and I have some questions / comments
(maybe some of my questions are really stupid, I do not know... :)


To begin, I have a very high-level comment about proxy execution: I
believe proxy execution is a very powerful concept, that can be used in
many cases, not only to do inheritance on mutual exclusion (think, for
example, about pipelines of tasks: a task implementing a stage of the
pipeline can act as a proxy for the task implementing the previous
stage).

So, I would propose to make the proxy() function of patch more generic,
and not strictly bound to mutexes. Maybe a task structure can contain a
list of tasks for which the task can act as a proxy, and we can have a
function like "I want to act as a proxy for task T" to be invoked when
a task blocks?



			Luca

  parent reply	other threads:[~2018-10-10 10:34 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-09  9:24 [RFD/RFC PATCH 0/8] Towards implementing proxy execution Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 1/8] locking/mutex: Convert mutex::wait_lock to raw_spinlock_t Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 2/8] locking/mutex: Removes wakeups from under mutex::wait_lock Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 3/8] locking/mutex: Rework task_struct::blocked_on Juri Lelli
2018-10-10 10:43   ` luca abeni
2018-10-10 11:06     ` Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 4/8] sched: Split scheduler execution context Juri Lelli
2019-05-06 11:06   ` Claudio Scordino
2018-10-09  9:24 ` [RFD/RFC PATCH 5/8] sched: Add proxy execution Juri Lelli
2018-10-10 11:10   ` luca abeni
2018-10-11 12:34     ` Juri Lelli
2018-10-11 12:53       ` Peter Zijlstra
2018-10-11 13:42         ` Juri Lelli
2018-10-12  7:22         ` luca abeni
2018-10-12  8:30           ` Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 6/8] locking/mutex: make mutex::wait_lock irq safe Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 7/8] sched: Ensure blocked_on is always guarded by blocked_lock Juri Lelli
2018-10-09  9:24 ` [RFD/RFC PATCH 8/8] sched: Fixup task CPUs for potential proxies Juri Lelli
2018-10-09  9:44 ` [RFD/RFC PATCH 0/8] Towards implementing proxy execution Peter Zijlstra
2018-10-09  9:58   ` Juri Lelli
2018-10-09 10:51 ` Sebastian Andrzej Siewior
2018-10-09 11:56   ` Daniel Bristot de Oliveira
2018-10-09 12:35     ` Juri Lelli
2018-10-10 10:34 ` luca abeni [this message]
2018-10-10 10:57   ` Peter Zijlstra
2018-10-10 11:16     ` luca abeni
2018-10-10 11:23       ` Peter Zijlstra
2018-10-10 12:27         ` Juri Lelli
2018-10-10 11:56 ` Henrik Austad
2018-10-10 12:24   ` Peter Zijlstra
2018-10-10 13:48     ` Daniel Bristot de Oliveira
2018-10-10 12:36   ` Juri Lelli

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