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 EA1144C70 for ; Thu, 8 Feb 2024 00:08:23 +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=1707350904; cv=none; b=dxqINc6JMqQNKb/A/KxHmsl3zZDtFt5uQEV5yzwLpDlykOrnBZXrDbe+c1DNrmNhtT+tHwwtkv5UzmPM0baKRmtwuZIaJLTMCEG5z629Hzn/++jaguUGJ9nJ8WtPXzJmYIekr9MuH1CfMa99ckpor/NjsCYQLJzpA1xjYCXZPBs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707350904; c=relaxed/simple; bh=zpFL9tuc+VckuTDiG9NM15A9S+EbfXl30c0elvw5tTM=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=r8AXYKaamPKCQSvmYMW0Ntyym3K/DPzFTifTc0PFpwVq4F46543tp8wUXU99JUOAijcPWUPyeX0FASjakafv1Tp4zPbbzZbOfCeXzHrZtbslfq4krFBnDG4eByTEeWeblzM/+tuPBW5iQRTCTyysMH88KYwrapuVN/TD7mUhVKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=osKux0YI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="osKux0YI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DC73C433C7; Thu, 8 Feb 2024 00:08:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1707350903; bh=zpFL9tuc+VckuTDiG9NM15A9S+EbfXl30c0elvw5tTM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=osKux0YIteV3Jlbv7wlzFCk3jUqr8BjkFANBLBePHJdbgi1La88MZKOHhp/PHu3kA dll2N1SW5QC14Adl5a4trJNJDWvhX85ucdeJQcJKXYvm0W2gGiZPVWO57HsmVnIKKY SOnn6r1fzBe/0v6v7xBXO98JckBHMVlZCsjEmW8E= Date: Wed, 7 Feb 2024 16:08:22 -0800 From: Andrew Morton To: Anshuman Khandual Cc: linux-mm@kvack.org, alexandru.elisei@arm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/cma: Add sysfs file 'release_pages_success' Message-Id: <20240207160822.c061cc98d6ffd2ab1ecac38a@linux-foundation.org> In-Reply-To: <8d9f2950-6805-481f-a5e7-e5ea45128fb5@arm.com> References: <20240206045731.472759-1-anshuman.khandual@arm.com> <20240206093857.d834af4f96d643c53e29e02d@linux-foundation.org> <8d9f2950-6805-481f-a5e7-e5ea45128fb5@arm.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 7 Feb 2024 10:04:31 +0530 Anshuman Khandual wrote: > > The changelog doesn't explain why Linux needs this feature. The value > > to our users. Perhaps that info is buried in the link which is buried > > below the ^---$, but as this is the most important part of a changelog, > > it really should be spelled out here, completely and carefully please. > > Does this look better ? > > mm/cma: Add sysfs file 'release_pages_success' > > This adds the following new sysfs file tracking the number of successfully > released pages from a given CMA heap area. This file will be available via > CONFIG_CMA_SYSFS and help in determining active CMA pages available on the > CMA heap area. This adds a new 'nr_pages_released' (CONFIG_CMA_SYSFS) into > 'struct cma' which gets updated during cma_release(). > > /sys/kernel/mm/cma//release_pages_success > > After this change, an user will be able to find active CMA pages available > in a given CMA heap area via the following method. > > Active pages = alloc_pages_success - release_pages_success > > That's valuable information for both software designers, and system admins > as it allows them to tune the number of CMA pages available in the system. > This increases user visibility for allocated CMA area and its utilization. yup, thanks. I added the patch with the above for a changelog.