From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32D33C64EAD for ; Tue, 9 Oct 2018 09:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D040021479 for ; Tue, 9 Oct 2018 09:44:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fTtEGEBS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D040021479 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726445AbeJIRBA (ORCPT ); Tue, 9 Oct 2018 13:01:00 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37424 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725823AbeJIRA7 (ORCPT ); Tue, 9 Oct 2018 13:00:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ULsf3qLVKhw0XY+gqJq+0f4hV7OmFUu9a7ZaHIAD8aw=; b=fTtEGEBSgkPPJyjhx3kkikslE WC6quQyhJ4pt4jBqN5s2RuLmpLvX/ynKkLttYmtvxbqXo8yHU6Y/ZBloz6xh558Fdb/Reptj4NKd5 FfWWUtN/vxhwXErn6Rfqh7nETdeRsbHwb5TMh/zUNuIjx6NK5GYQHHspY+DTj8/UKv5an2Dv4AY0I LCijSHraTf+/7+llWkLiVvX21v4jPU6EIysoiac6O02waVJcZm/HVjCvjvGBycjWdsixmp5ptOqxq RRhx/M/CkhDsoGNwkkNkK0aGcA5OueeQwZwNFNxBGVRTIuOQv+IhqPsdZlIUn4+8cH1eKaHxCYjHx UC3JTXGQg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g9oZJ-00036C-6v; Tue, 09 Oct 2018 09:44:45 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 441FF20281DC1; Tue, 9 Oct 2018 11:44:41 +0200 (CEST) Date: Tue, 9 Oct 2018 11:44:41 +0200 From: Peter Zijlstra To: Juri Lelli Cc: 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, 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 Message-ID: <20181009094441.GI5663@hirez.programming.kicks-ass.net> References: <20181009092434.26221-1-juri.lelli@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181009092434.26221-1-juri.lelli@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 09, 2018 at 11:24:26AM +0200, Juri Lelli 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. Well that, and mutex was 'simple', I didn't have to go rip out all the legacy PI crud. If this all ends up working well, the solution is 'simple' and we can simply copy mutex to rt_mutex or something along those lines if we want to keep the distinction between them. Alternatively we simply delete rt_mutex. Thanks for reviving this.. it's been an 'interesting' year and a half since I wrote all this and I've really not had time to work on it.