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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 D1CD3C282CB for ; Tue, 5 Feb 2019 13:24:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7F332073D for ; Tue, 5 Feb 2019 13:24:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729489AbfBENYs (ORCPT ); Tue, 5 Feb 2019 08:24:48 -0500 Received: from mail-vs1-f66.google.com ([209.85.217.66]:41135 "EHLO mail-vs1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726276AbfBENYr (ORCPT ); Tue, 5 Feb 2019 08:24:47 -0500 Received: by mail-vs1-f66.google.com with SMTP id t17so2108581vsc.8; Tue, 05 Feb 2019 05:24:46 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mH2jC//BX4csPlxzLWPxIbl/VLPdX2MNzc/nlQzQz8Q=; b=g3YaCJcISPixq7aUuf35LNeOkryoASZsaYYP4JnvgSu6j8PtbZJj79oe743QGuXlM8 pSyh6fsgRGsh2/A6gIPEIWbTjIcZiKYnZdFGIwndaGo6vZA2JkwpU3rXX0mQjuKbJENA w9JEfYl/F8wPwKBVTCfeaCIleLQiUliSRuVV9Zu9+8dd8i9nshnEA8hKJbdFwN0PMy+A EUd6k0mcnsolXK80Dkgw2ISGJ0CgphTpWGvQkzHgui+43WmHPhOgp+L0ca5En/vgvr8N YF1CC1OgCBfwK19kOLJYXZ7eNuOpGHMpoDv2AQR0oUMLT/phHOTDsS4bfiWBuzkZgziY brAA== X-Gm-Message-State: AHQUAua3qL84bJA7OJQh2VJzz3L/kqfB8ikbELQqlPgIM7gp5h6nYNMR XWlcsWDxoFNY9PKyeP1tBvgr+D0MmqyRuEiK5cA= X-Google-Smtp-Source: AHgI3IZGiOTTw8sZiDzZNxEUVJfcek13r1NV7ffeSdfvgl9Jp03HBQFnX+NKK7wxVbto9ZhTYk3nwT3JsD0+hzp5ILU= X-Received: by 2002:a67:d119:: with SMTP id u25mr1891966vsi.63.1549373086077; Tue, 05 Feb 2019 05:24:46 -0800 (PST) MIME-Version: 1.0 References: <1548846984-2044-1-git-send-email-vincent.guittot@linaro.org> In-Reply-To: From: Geert Uytterhoeven Date: Tue, 5 Feb 2019 14:24:33 +0100 Message-ID: Subject: Re: [PATCH v2 ] PM-runtime: fix deadlock with ktime To: Ulf Hansson Cc: Vincent Guittot , Linux PM , Linux Kernel Mailing List , Linux ARM , linux-omap , "Rafael J. Wysocki" , Biju Das , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ulf, On Wed, Jan 30, 2019 at 1:15 PM Ulf Hansson wrote: > On Wed, 30 Jan 2019 at 12:16, Vincent Guittot > wrote: > > > > A deadlock has been seen when swicthing clocksources which use PM runtime. > > The call path is: > > change_clocksource > > ... > > write_seqcount_begin > > ... > > timekeeping_update > > ... > > sh_cmt_clocksource_enable > > ... > > rpm_resume > > Hmm, isn't this already a problem in genpd then? > > In genpd's ->runtime_resume() callback (genpd_runtime_resume()) we > call ktime_get() to measure the latency of running the callback. > > Or, perhaps irq_safe_dev_in_no_sleep_domain() returns true for the > genpd + device in question, which means the ktime thingy is skipped. > > Geert? Correct. After adding dev_info(dev, "%s: pm_runtime_is_irq_safe = %d, genpd_is_irq_safe(%s) = %d => %s\n", __func__, pm_runtime_is_irq_safe(dev), genpd->name, genpd_is_irq_safe(genpd), ret ? "true" : "false"); I see on R-Car M2-W: sh_cmt ffca0000.timer: irq_safe_dev_in_no_sleep_domain: pm_runtime_is_irq_safe = 1, genpd_is_irq_safe(always-on) = 0 => true For all other devices, the result is false. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds 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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 DD6DBC282CC for ; Tue, 5 Feb 2019 13:24:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A98C02073D for ; Tue, 5 Feb 2019 13:24:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kWQsTWT5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A98C02073D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sD+r9y9TYPIvv+mL9bETy8RIaLNj5ObqI2Y3iPNrlcA=; b=kWQsTWT5t+dj8f J2CkO8ZTLzHYn7YCddTU/OstdetCaXeZH4Dk+i/o7imwvQRbVSOhvQaICLNQjWPigPRbdoqSaZkQ9 4OWf3UEJZXIYASXY1XmzLToaTOruTLlC84dl44cPfQeqKVXO7onVxL25VP2yPlqP7AiK5jSTaxHjM TTQbmXIP4ltn/U+5YYKsp3qyrunV/D8iMzKNVM3o+0GPOtFXmYO4b9EJAkDmNrzWtddQYDM6S/t5m rUL7a62NlMBPBhgXRZVCyAyZTa44y0o5PHFf2H246vdomSrK9U0VAudGz+fWwiNUoLh9RvobPfwbP osqCsRevt2FyBSPorxDA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gr0iZ-0005nI-UY; Tue, 05 Feb 2019 13:24:51 +0000 Received: from mail-vs1-f66.google.com ([209.85.217.66]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gr0iW-0005my-CT for linux-arm-kernel@lists.infradead.org; Tue, 05 Feb 2019 13:24:49 +0000 Received: by mail-vs1-f66.google.com with SMTP id b74so2094026vsd.9 for ; Tue, 05 Feb 2019 05:24:46 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mH2jC//BX4csPlxzLWPxIbl/VLPdX2MNzc/nlQzQz8Q=; b=M5nfh9DHgf3yhYoKHrZAv5kud0hdFAXYitYONLqNEzgcIGdxh4jTwBmdEKSLKvAs9G 0UwM78rRrRyrLO9+Z3iUiMk9/D7oqzAbRKJ/bcSeMy1fC7s4xBN/BCm7ajNh29++vSup /u+SSqIff07TrZ8EHljPa413fRtDjbhEvDD16n/kRFSrD9G+pqydVkQWtw29hg0wsv5u pktItQtTuDmlx/iRXNfh5iuwO7OYfzWpNQ1DmuJibfbPYMb0dLHfDQ+jHVoFqjJSARrT K9sQk48FaKYIpGJe0O3dgTbbMUK1LPMxgcgguOCfoNvrvkp6eLTo99Q2rvVbCbmzfv9F NNUA== X-Gm-Message-State: AHQUAuY3Vtzt2BJInsqFBCUKdzYQUf/NDGlpJQCWgpFpW7784owwG4uz I/PZmTb7XNZ/P+X5z+RxZ1OklBuCUM9EUJ+yxIk= X-Google-Smtp-Source: AHgI3IZGiOTTw8sZiDzZNxEUVJfcek13r1NV7ffeSdfvgl9Jp03HBQFnX+NKK7wxVbto9ZhTYk3nwT3JsD0+hzp5ILU= X-Received: by 2002:a67:d119:: with SMTP id u25mr1891966vsi.63.1549373086077; Tue, 05 Feb 2019 05:24:46 -0800 (PST) MIME-Version: 1.0 References: <1548846984-2044-1-git-send-email-vincent.guittot@linaro.org> In-Reply-To: From: Geert Uytterhoeven Date: Tue, 5 Feb 2019 14:24:33 +0100 Message-ID: Subject: Re: [PATCH v2 ] PM-runtime: fix deadlock with ktime To: Ulf Hansson X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190205_052448_428122_7624A71E X-CRM114-Status: GOOD ( 12.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vincent Guittot , Linux PM , "Rafael J. Wysocki" , Linux Kernel Mailing List , Biju Das , Linux-Renesas , linux-omap , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ulf, On Wed, Jan 30, 2019 at 1:15 PM Ulf Hansson wrote: > On Wed, 30 Jan 2019 at 12:16, Vincent Guittot > wrote: > > > > A deadlock has been seen when swicthing clocksources which use PM runtime. > > The call path is: > > change_clocksource > > ... > > write_seqcount_begin > > ... > > timekeeping_update > > ... > > sh_cmt_clocksource_enable > > ... > > rpm_resume > > Hmm, isn't this already a problem in genpd then? > > In genpd's ->runtime_resume() callback (genpd_runtime_resume()) we > call ktime_get() to measure the latency of running the callback. > > Or, perhaps irq_safe_dev_in_no_sleep_domain() returns true for the > genpd + device in question, which means the ktime thingy is skipped. > > Geert? Correct. After adding dev_info(dev, "%s: pm_runtime_is_irq_safe = %d, genpd_is_irq_safe(%s) = %d => %s\n", __func__, pm_runtime_is_irq_safe(dev), genpd->name, genpd_is_irq_safe(genpd), ret ? "true" : "false"); I see on R-Car M2-W: sh_cmt ffca0000.timer: irq_safe_dev_in_no_sleep_domain: pm_runtime_is_irq_safe = 1, genpd_is_irq_safe(always-on) = 0 => true For all other devices, the result is false. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel