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[193.205.81.5]) by smtp.gmail.com with ESMTPSA id 90-v6sm25374867wrg.86.2018.10.09.04.56.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Oct 2018 04:56:41 -0700 (PDT) Subject: Re: [RFD/RFC PATCH 0/8] Towards implementing proxy execution To: Sebastian Andrzej Siewior , Juri Lelli Cc: peterz@infradead.org, mingo@redhat.com, rostedt@goodmis.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, alessio.balsini@gmail.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 References: <20181009092434.26221-1-juri.lelli@redhat.com> <20181009105112.bhqlrabdt5ae5qmm@linutronix.de> From: Daniel Bristot de Oliveira Message-ID: <9837aa4b-1bd4-bc6a-84f7-0b8704995d44@redhat.com> Date: Tue, 9 Oct 2018 13:56:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20181009105112.bhqlrabdt5ae5qmm@linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/18 12:51 PM, Sebastian Andrzej Siewior wrote: >> The main concerns I have with the current approach is that, being based >> on mutex.c, it's both >> >> - not linked with futexes >> - not involving "legacy" priority inheritance (rt_mutex.c) >> >> I believe one of the main reasons Peter started this on mutexes is to >> have better coverage of potential problems (which I can assure everybody >> it had). I'm not yet sure what should we do moving forward, and this is >> exactly what I'd be pleased to hear your opinions on. > wasn't the idea that once it works to get rid of rt_mutex? As far as I know, it is. But there are some additional complexity involving a -rt version of this patch, for instance: What should the protocol do if the thread migrating is with migration disabled? The side effects of, for instance, ignoring the migrate_disable() would add noise for the initial implementation... too much complexity at once. IMHO, once it works in the non-rt, it will be easier to do the changes needed to integrate it with -rt. Thoughts? -- Daniel