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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84369E732FB for ; Thu, 28 Sep 2023 17:06:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 043E66B0246; Thu, 28 Sep 2023 13:06:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F0FE86B0248; Thu, 28 Sep 2023 13:06:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D3E0E6B0249; Thu, 28 Sep 2023 13:06:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C521A6B0246 for ; Thu, 28 Sep 2023 13:06:22 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 9A0851C9CDC for ; Thu, 28 Sep 2023 17:06:22 +0000 (UTC) X-FDA: 81286634604.30.1137E0A Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf29.hostedemail.com (Postfix) with ESMTP id B74AB120023 for ; Thu, 28 Sep 2023 17:06:20 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=T1EG9wCs; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf29.hostedemail.com: domain of jlayton@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=jlayton@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695920780; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=DNM/VlOuUT51G0bnMvXw+94sqfHee3c68K5vLwQuau4=; b=uLIYefzxdYUCrAX9m1wkuNTR9G+XM0+Ljz0sgjWU12Y3qzInwpCCUzf5Ei1SfBQADX+FN+ abuiFhyND3NBXZseNIs22MgSuFJjJqr/NtUUuJFD07KXdvDpYiXZKKHncTmMk0mz3Ee3L1 7f18SvHZZzpLghPZ8A90Ie5z2zVuKlQ= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=T1EG9wCs; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf29.hostedemail.com: domain of jlayton@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=jlayton@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695920780; a=rsa-sha256; cv=none; b=r/z5ba7Ol1WiHjEth12NE3jS8Dkw8jzk+1aVLzgSOtcEt+Z/H2A9Tdf4it/dMvKU+Su87j hxyqgK7iSRTgYY070My2LtNBte01eJwEJrVsdFy/tQnmTLwBeuWLP4phqDZQx6wTzLQIJf 3ffhc7hkDH20qwc2uve4T6p7DsA4bn0= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A10FF61D47; Thu, 28 Sep 2023 17:06:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9B31C433C8; Thu, 28 Sep 2023 17:06:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695920779; bh=DNM/VlOuUT51G0bnMvXw+94sqfHee3c68K5vLwQuau4=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=T1EG9wCsmdavqbCDgZQmRYDY2hTjqQ8HvqU7HakqZRoba0+m8x7Xb0PPxNH54fTbK gxOvKBrhR/NUHAqOFYLgQFvCS4fbqqpdpyJ0meCz+VJBZB5WwUDXaofxixCnDwGA2b xVhvTR3lvjwhcUNCr4cL+zM4prum42dBj/EqssN3wQ5xwZohTtnO5wenm4djJ5rTsg au+O/I2DWLjGqSGQ9+pJFDrXNkgJ5uSZlH8zfxoOHymWjEqjSumVZbYplcXqZfm3+f KDfZ0aAr31be94G8szYCClaMWLFdZEYGpG76Y3w4tHoT3E7mgxWznMj5HFQTi8O+xa SaKUjb/2UX2Ww== Message-ID: Subject: Re: [PATCH 86/87] fs: switch timespec64 fields in inode to discrete integers From: Jeff Layton To: Arnd Bergmann , Alexander Viro , Christian Brauner , Linus Torvalds , David Sterba , Amir Goldstein , Theodore Ts'o , "Eric W. Biederman" , Kees Cook , Jeremy Kerr , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Greg Kroah-Hartman , Arve =?ISO-8859-1?Q?Hj=F8nnev=E5g?= , Todd Kjos , Martijn Coenen , Joel Fernandes , Carlos Llamas , Suren Baghdasaryan , Mattia Dongili , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Brad Warrum , Ritu Agarwal , Hans de Goede , Ilpo =?ISO-8859-1?Q?J=E4rvinen?= , Mark Gross , Jiri Slaby , Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck , David Sterba , David Howells , Marc Dionne , Ian Kent , Luis de Bethencourt , Salah Triki , "Tigran A. Aivazian" , Chris Mason , Josef Bacik , Xiubo Li , Ilya Dryomov , Jan Harkes , coda@cs.cmu.edu, Joel Becker , Christoph Hellwig , Nicolas Pitre , "Rafael J . Wysocki" , Ard Biesheuvel , Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu , Namjae Jeon , Sungjong Seo , Jan Kara , Andreas Dilger , Jaegeuk Kim , OGAWA Hirofumi , Christoph Hellwig , Miklos Szeredi , Bob Peterson , Andreas Gruenbacher , Richard Weinberger , Anton Ivanov , Johannes Berg , Mikulas Patocka , Mike Kravetz , Muchun Song , Jan Kara , David Woodhouse , Dave Kleikamp , Tejun Heo , Trond Myklebust , Anna Schumaker , Chuck Lever , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Ryusuke Konishi , Anton Altaparmakov , Konstantin Komarov , Mark Fasheh , Joseph Qi , Bob Copeland , Mike Marshall , Martin Brandenburg , Luis Chamberlain , Iurii Zaikin , Tony Luck , "Guilherme G. Piccoli" , Anders Larsen , Steve French , Paulo Alcantara , Ronnie Sahlberg , Shyam Prasad N , Sergey Senozhatsky , Phillip Lougher , Steven Rostedt , Masami Hiramatsu , Evgeniy Dushistov , Chandan Babu R , "Darrick J. 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Hallyn" , Stephen Smalley , Eric Paris Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-rdma@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, v9fs@lists.linux.dev, linux-afs@lists.infradead.org, autofs@vger.kernel.org, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-efi@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, gfs2@lists.linux.dev, linux-um@lists.infradead.org, linux-mtd@lists.infradead.org, jfs-discussion@lists.sourceforge.net, linux-nfs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, ntfs3@lists.linux.dev, ocfs2-devel@lists.linux.dev, linux-karma-devel@lists.sourceforge.net, devel@lists.orangefs.org, linux-unionfs@vger.kernel.org, linux-hardening@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-trace-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, bpf@vger.kernel.org, Netdev , apparmor@lists.ubuntu.com, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Date: Thu, 28 Sep 2023 13:06:03 -0400 In-Reply-To: <6020d6e7-b187-4abb-bf38-dc09d8bd0f6d@app.fastmail.com> References: <20230928110554.34758-1-jlayton@kernel.org> <20230928110554.34758-2-jlayton@kernel.org> <6020d6e7-b187-4abb-bf38-dc09d8bd0f6d@app.fastmail.com> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.48.4 (3.48.4-1.fc38) MIME-Version: 1.0 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B74AB120023 X-Stat-Signature: tohz611rq9bwetzra39o3zsf6k87kk7r X-Rspam-User: X-HE-Tag: 1695920780-871976 X-HE-Meta: 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 paYarrra O/pC4hRBaQm82JGu+dsATdU/usufIdkPIt63hS5mPwDTfdUIp/+p0mrYlvWXWdbgQheCJIHBQSequ7ji0EMdSAXXh33CaynNTKY2/Qp3O74j6FDefanQFPgUFuGCudq4gOvI7okyVWEdhSaHoBFWvXmVKdSZY/2/CYTyDbVRFjR6rRSbGWCVcoBcqEWAEkBOOX2uPX4X/h8ZF9xnStW0Xu9/9/PZwXgl3U2U+QAVUD3mCowfwFglmAPPoT5Bc0O8weUYLK0uTWznRQUCfOXJqtDSfp5dV6llvmhN3z+Nhdcas0G6wE3K4YJECxLAhqouFfwCvbMy1TuYadklajQ/mFEXkJaH5zzr4jQas/1gxbmUzCTtw/Cli9yENoDJ7+aBRfPRqXcCRnlw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 2023-09-28 at 11:48 -0400, Arnd Bergmann wrote: > On Thu, Sep 28, 2023, at 07:05, Jeff Layton wrote: > > This shaves 8 bytes off struct inode, according to pahole. > >=20 > > Signed-off-by: Jeff Layton >=20 > FWIW, this is similar to the approach that Deepa suggested > back in 2016: >=20 > https://lore.kernel.org/lkml/1452144972-15802-3-git-send-email-deepa.kern= el@gmail.com/ >=20 > It was NaKed at the time because of the added complexity, > though it would have been much easier to do it then, > as we had to touch all the timespec references anyway. >=20 > The approach still seems ok to me, but I'm not sure it's worth > doing it now if we didn't do it then. >=20 I remember seeing those patches go by. I don't remember that change being NaK'ed, but I wasn't paying close attention at the time=20 Looking at it objectively now, I think it's worth it to recover 8 bytes per inode and open a 4 byte hole that Amir can use to grow the i_fsnotify_mask. We might even able to shave off another 12 bytes eventually if we can move to a single 64-bit word per timestamp.=20 It is a lot of churn though. --=20 Jeff Layton