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 8F63215E5A6; Mon, 1 Jul 2024 14:12:33 +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=1719843153; cv=none; b=AWpDw4D2yabVnV19QO82sTjVeSWTTkU+Nvp3AnkAFeKKIhEsYUEc9B3JKGjukhoYj9Dw6c045GUXjy72t8qwWcQOBK9dXbtRycLedAuMajJTfDZqBD3rP5G3UlIIMgD+ht8pqM6YAyjxWm+bkMmpHwpY4Nmrfq9mmeKlfr7upqs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719843153; c=relaxed/simple; bh=1VVWwQxpbYpxgTGynZjIRizmv2vMmvHZ76g/uhUNoXw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=DbQjITkpBzwUGgslzg1pvc3threVNDOtfsKznridTMqOi5Kt4drcQ299g2X6gYM9XgQOvkGwazjCjMXMMTXAaRYvKC1TK6Yqfj+jYI3ZZBQp/Xmsyq+u0fZwQUihGrM/GPOC7i8QQ5Wf5gt1f4Jf6hTo2a6LddUhA7r6fsXIXIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bx6gl0u0; 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="Bx6gl0u0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4F24C116B1; Mon, 1 Jul 2024 14:12:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719843153; bh=1VVWwQxpbYpxgTGynZjIRizmv2vMmvHZ76g/uhUNoXw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=Bx6gl0u0KpVIjrIpzrfYuY6WoBWEJEEFsy7b/cg2a/dYiOrt9fM/DJGDrY4QzS/z2 BtJ2c2Y8K4NKN+etRhqcUQVzjCCN2h5D7xdOOXxL5/4RUam5MFz6a5hFvUmmHrbjSW GBdgrvmiHCBMiiPg8KwsHfBQSvqTTXGjspMQ8+oIkERaDsrnslkOSLiNDBbJCCVNht /HKEoG8hniCJoiHW0rvXZ6VGbyPTaEMa8dRiFPRr0P5g4yDZ+n/Rir8GoP0agHiEDr zbOJgH3sUJKUT1OpmSMSjDXDkXEvDtLAmCs0lSDgEg0QZPn/+DDoPCdTUZUf/Qmq/8 RZQkXLVyvBeww== Message-ID: <1c3cee9f7ef81e1da09e0c7b4ee1e47dc9161a75.camel@kernel.org> Subject: Re: [PATCH v2 00/11] fs: multigrain timestamp redux From: Jeff Layton To: Josef Bacik Cc: 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 , David Sterba , Hugh Dickins , Andrew Morton , Andi Kleen , 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 Date: Mon, 01 Jul 2024 10:12:29 -0400 In-Reply-To: <20240701135332.GD504479@perftesting> References: <20240701-mgtime-v2-0-19d412a940d9@kernel.org> <20240701135332.GD504479@perftesting> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.4 (3.50.4-1.fc39) Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2024-07-01 at 09:53 -0400, Josef Bacik wrote: > On Mon, Jul 01, 2024 at 06:26:36AM -0400, Jeff Layton wrote: > > This set is essentially unchanged from the last one, aside from the > > new file in Documentation/. I had a review comment from Andi Kleen > > suggesting that the ctime_floor should be per time_namespace, but I > > think that's incorrect as the realtime clock is not namespaced. > >=20 > > At LSF/MM this year, we had a discussion about the inode change > > attribute. At the time I mentioned that I thought I could salvage the > > multigrain timestamp work that had to be reverted last year [1].=C2=A0 = That > > version had to be reverted because it was possible for a file to get a > > coarse grained timestamp that appeared to be earlier than another file > > that had recently gotten a fine-grained stamp. > >=20 > > This version corrects the problem by establishing a per-time_namespace > > ctime_floor value that should prevent this from occurring. In the above > > situation that was problematic before, the two files might end up with > > the same timestamp value, but they won't appear to have been modified i= n > > the wrong order. > >=20 > > That problem was discovered by the test-stat-time gnulib test. Note tha= t > > that test still fails on multigrain timestamps, but that's because its > > method of determining the minimum delay that will show a timestamp > > change will no longer work with multigrain timestamps. I have a patch t= o > > change the testcase to use a different method that I've posted to the > > bug-gnulib mailing list. > >=20 > > The big question with this set is whether the performance will be > > suitable. The testing I've done seems to show performance parity with > > multigrain timestamps enabled, but it's hard to rule this out regressin= g > > some workload. > >=20 > > This set is based on top of Christian's vfs.misc branch (which has the > > earlier change to track inode timestamps as discrete integers). If ther= e > > are no major objections, I'd like to let this soak in linux-next for a > > bit to see if any problems shake out. > >=20 > > [1]: https://lore.kernel.org/linux-fsdevel/20230807-mgctime-v7-0-d1dec1= 43a704@kernel.org/ > >=20 > > Signed-off-by: Jeff Layton >=20 > I have a few nits that need to be addressed, but you can add >=20 > Reviewed-by: Josef Bacik >=20 > to the series once they're addressed.=C2=A0 Thanks, >=20 Thanks! Fixed them up in my tree. I left the IS_I_VERSION check out as well, and added a note to the changelog on the btrfs patch. --=20 Jeff Layton