From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 71D875F871; Wed, 14 Feb 2024 16:06:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707926815; cv=none; b=ncEXcs6w7frit687tDZZkmA5DFuqzultu/thLRa9SfXtUWfLXPNYYBSscbz2aY61FiAgdpjiDGJmv1Jtt21Of6TjFDcIiHd8/opbtWcTq1EDBNdfekd/Bj3No33D5P0wWqTDXrucwrRdTbbWb/rm3iamdXz5meAUYRrXjwUSLmg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707926815; c=relaxed/simple; bh=7qfrnwneSTETdWc/MSsQJm5c32O3g3e00oMGNngWvdA=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=bd9/ZoVBs25oQxI4KFuXoF6IarmZVgFRA9pzQyrTp+jc0mbdtm8mSiroXJUPHc3nv+kOWXRtk2z7JcCLE8TQaTiw3zIwCheqe9CHInfgXa2isgsuXfMCy07vjpmr9toRgQdPR86OYdkYit5JAiINTgKoOVbBI2lviqhNeXuJrR0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U9tgLLbz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U9tgLLbz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF8A5C433F1; Wed, 14 Feb 2024 16:06:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707926815; bh=7qfrnwneSTETdWc/MSsQJm5c32O3g3e00oMGNngWvdA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=U9tgLLbzW1pYyi63ZIZJXqnQMdQ7wpz/W6lsEZg0Vj2Aiw25wTfuXXhU27ljokdqG Y9ZKkeN9rcDJTudtdXqjl/yNA4hXi1HNVEAQzx5PUMaNPkaSeI78Ym1La6TriopzGJ kEXTbA68dpMJmlr8smYAcoG+YGXrzsMo/I8dut7g3gGm9Ejs3WI2McNKY6o8TCAYC+ ffGE6h8GpLgpjv62GNDvgA5BSDP5gjj74dLGRotkxhiER3hMFkpqZMKKk14mnVihD9 BD6ecs/6mIGfo7m8XF7E1qk2bxg+EBTpHNf3ouJC1NLyCKk0TTfXnsBs9C6psV/G+v x3Qb+7cpL/ykw== Date: Wed, 14 Feb 2024 10:06:52 -0600 From: Bjorn Helgaas To: Raag Jadav Cc: Andy Shevchenko , bhelgaas@google.com, jarkko.nikula@linux.intel.com, mika.westerberg@linux.intel.com, stanislaw.gruszka@linux.intel.com, lukas@wunner.de, rafael@kernel.org, ilpo.jarvinen@linux.intel.com, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, sashal@kernel.org Subject: Re: [PATCH v1] PCI / PM: Really allow runtime PM without callback functions Message-ID: <20240214160652.GA1254564@bhelgaas> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Feb 14, 2024 at 03:20:35PM +0200, Raag Jadav wrote: > On Wed, Feb 14, 2024 at 03:01:29PM +0200, Andy Shevchenko wrote: > > On Wed, Feb 14, 2024 at 12:43:35PM +0200, Raag Jadav wrote: > > > On Tue, Feb 13, 2024 at 02:06:48PM -0600, Bjorn Helgaas wrote: > > > > On Mon, Feb 12, 2024 at 12:02:33PM +0530, Raag Jadav wrote: > > > > ... > > > > > > > 0) | pm_runtime_work() { > > > > > 0) | rpm_idle() { > > > > > 0) | rpm_check_suspend_allowed() { > > > > > 0) 1.500 us | __dev_pm_qos_resume_latency(); /* = 0x7fffffff */ > > > > > 0) 4.840 us | } /* rpm_check_suspend_allowed = 0x0 */ > > > > > 0) 1.550 us | __rpm_get_callback(); /* = 0xffffffffb4bc84f0 */ > > > > > 0) 1.800 us | pci_pm_runtime_idle(); /* = -38 */ > > > > > 0) + 17.070 us | } /* rpm_idle = -38 */ > > > > > 0) + 22.450 us | } /* pm_runtime_work = -38 */ > > > > > > > > What is this timing information telling me? > > > > > > It's a raw ftrace dump. > > > > (Told ya that people would be surprised with this without seeing how you get > > this and what fields mean) > > I can add stat headers in v2 which I think will be more helpful. That's not what I was asking. *Why* is the ftrace dump here? Is the point that we're calling a function we shouldn't? That this patch improves performance? Without some interpretation of what the dump shows, it's just noise. Bjorn