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[209.132.180.67]) by mx.google.com with ESMTP id h126-v6si11436932pfg.126.2018.06.06.08.05.52; Wed, 06 Jun 2018 08:06:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=BuI1jTEi; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752384AbeFFPDU (ORCPT + 99 others); Wed, 6 Jun 2018 11:03:20 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:49518 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751973AbeFFPDS (ORCPT ); Wed, 6 Jun 2018 11:03:18 -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=F0xGeKUlqfCmWP/w1ynasr9DA6+c05nMrmrlZu+KWWw=; b=BuI1jTEigc4pjsDgClHkN9++w vCxnrcNEeXFPlc8PVdMADcHcVANu+zpIMa6dnE76l1IPcrwz6PGzqbY4Kpx7s0S6TWFvlJMyoir8G 5+QolsoYlyXeU+ylHOwD9KYpzMJBlYykcXGhm2jMTeTZomnSMf4S3qWpIPZ3Z4m9HaalpxylCgmo9 yiG9Fij62VaWGwIQAd8RZwYIjHXaUeRNTGEjEJ4fcgu4BAkwJneIFHD2om2v79ba1eaG1kDjvV83S LWRh07BITD2PLlnXX4s1G89clDXIIiLqlQiYkM/E4l9AF5K/vklxqvWhiSCQZTgtzMbAAGE7Rjpcn 65vm8ysmg==; 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 1fQZxw-0000ea-Oh; Wed, 06 Jun 2018 15:03:12 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id EEAEB201EA7AB; Wed, 6 Jun 2018 17:03:10 +0200 (CEST) Date: Wed, 6 Jun 2018 17:03:10 +0200 From: Peter Zijlstra To: Oleg Nesterov Cc: "Kohli, Gaurav" , tglx@linutronix.de, mpe@ellerman.id.au, mingo@kernel.org, bigeasy@linutronix.de, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Neeraj Upadhyay , Will Deacon Subject: Re: [PATCH v1] kthread/smpboot: Serialize kthread parking against wakeup Message-ID: <20180606150310.GF12180@hirez.programming.kicks-ass.net> References: <830d7225-af90-a55a-991a-bb2023d538f1@codeaurora.org> <55221a5b-dd52-3359-f582-86830dd9f205@codeaurora.org> <20180605150841.GA24053@redhat.com> <20180605152212.GY12180@hirez.programming.kicks-ass.net> <20180605154053.GB12235@hirez.programming.kicks-ass.net> <20180605163515.GB24053@redhat.com> <20180605201316.GZ12198@hirez.programming.kicks-ass.net> <20180606135115.GA4609@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180606135115.GA4609@redhat.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 06, 2018 at 03:51:16PM +0200, Oleg Nesterov wrote: > In particular, I think that kthread_park() on a parked kthread > must not be possible. It happens though; I put in a WARN and someone triggered it -- although I could not reproduce :/