From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 D97901474BE; Tue, 9 Jul 2024 23:51:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720569064; cv=none; b=TFvvw2c/yr6PwYfrGzm6e1X5N/XUsWe2WItObIjs2vjViq9ID1xxFxLYHEd15GReIPunxWkAJpg+eR5iv4qftlpHDkkmAlxBt+N1fD5ex+L9etrXb97uHhGmV9ZdAfmgOnh2OXFkguOpnxM9eHSSl1l0qR6X5CrjLcJfqXJQKvg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720569064; c=relaxed/simple; bh=06szhZhvI5y/0ml1HztEAZfKngl9g/YYJWu9WNQ4sLM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rI+84Xf2G2rgFW86L2Zm+CaVFbcWAOIddwGqcFuW3PFvXG158EE3UuvVWI2bS9S2T+3Fy8Ii4WSpCg5yrDIJKu8pZgiPXCIWcBiZepm8uPvj+9eFzRhhlsc8i4kNrQEkMWZbuILInTWRCiF6gSxpigOPwAX40AGoaZHbzdrBjSI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=DCzTmhwt; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="DCzTmhwt" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description; bh=1MnKJi0jeAHhcjlp5AtWFQ8iIjqs+OJI3rZ7gK/CmMU=; b=DCzTmhwt94ownkzIzPjjLO9YFf eu92ryb30Y5fTRUbNpYryFLMftlaguCeCXoN5EOazjbAsFOs+tBSCQRNU7Q9+73B6Auj6hO18pDHa tVqNTGWjeWJdyOsHdlhu3/6ety3pwwmck57aAkc4fbaq1wmZauOvq+WLqpISS8yRZqCLos8OaPI4C hs61AA6++huLcis6+2wfhFY8FKzdLoiDZGfl8hPNz2QPC/0WLP/nmKUoFVXt2uML9oLLHVZjGnISQ SNynxgD4UGwrFpzo35YzDs92U2UM4UsY3+jCn/D4vFLAhvCA1+Qv96t7MNQa7spkBp1odrX3/w5pV UYTO+k7A==; Received: from [50.53.4.147] (helo=[192.168.254.17]) by casper.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sRKbT-00000008U6L-2tpi; Tue, 09 Jul 2024 23:50:35 +0000 Message-ID: <420ac42f-dad2-4fd9-b36a-6405d14b6e25@infradead.org> Date: Tue, 9 Jul 2024 16:50:24 -0700 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 5/9] Documentation: add a new file documenting multigrain timestamps To: Jeff Layton , Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Chandan Babu R , "Darrick J. Wong" , Theodore Ts'o , Andreas Dilger , Chris Mason , Josef Bacik , David Sterba , Hugh Dickins , Andrew Morton , Jonathan Corbet Cc: Dave Chinner , Andi Kleen , Christoph Hellwig , Uros Bizjak , Kent Overstreet , kernel-team@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-doc@vger.kernel.org References: <20240708-mgtime-v4-0-a0f3c6fb57f3@kernel.org> <20240708-mgtime-v4-5-a0f3c6fb57f3@kernel.org> Content-Language: en-US From: Randy Dunlap In-Reply-To: <20240708-mgtime-v4-5-a0f3c6fb57f3@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/8/24 8:53 AM, Jeff Layton wrote: > Add a high-level document that describes how multigrain timestamps work, > rationale for them, and some info about implementation and tradeoffs. > > Signed-off-by: Jeff Layton > --- > Documentation/filesystems/multigrain-ts.rst | 120 ++++++++++++++++++++++++++++ > 1 file changed, 120 insertions(+) > > diff --git a/Documentation/filesystems/multigrain-ts.rst b/Documentation/filesystems/multigrain-ts.rst > new file mode 100644 > index 000000000000..e4f52a9e3c51 > --- /dev/null > +++ b/Documentation/filesystems/multigrain-ts.rst > @@ -0,0 +1,120 @@ > +Inode Timestamp Ordering > +======================== > + > +In addition just providing info about changes to individual files, file In addition to just > +timestamps also serve an important purpose in applications like "make". These > +programs measure timestamps in order to determine whether source files might be > +newer than cached objects.