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 89E3AC76195 for ; Wed, 22 Mar 2023 18:49:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1CB9F6B0071; Wed, 22 Mar 2023 14:49:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 17B896B0072; Wed, 22 Mar 2023 14:49:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 06AB96B0075; Wed, 22 Mar 2023 14:49:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id EBAF66B0071 for ; Wed, 22 Mar 2023 14:49:43 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id C52DEAAEC6 for ; Wed, 22 Mar 2023 18:49:43 +0000 (UTC) X-FDA: 80597423046.10.1C4DC63 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf05.hostedemail.com (Postfix) with ESMTP id 7E6FE100003 for ; Wed, 22 Mar 2023 18:49:40 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="Jg+7Mh/3"; spf=none (imf05.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1679510981; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5ch/QuOr2IZ30W763hH9kORlChf/b8rQ2pXYI9kCiyM=; b=LmPpMrdMb3+yyc66W1sdbfg6+GSGm43oRLUvEsYMxYaBodpr98ik3HLH1AtuQt91jnSGp/ F8CyrYCMC1UdPNsGQxPbQnDoWcLMMJpp7/+LYsdtWEAKNyxTelYBl7HhUn8Xm+6SoL8Y6k iSb/tIJymJGeuaCSKoDgXTNVfT6/plc= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="Jg+7Mh/3"; spf=none (imf05.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1679510981; a=rsa-sha256; cv=none; b=bR/F1cruQ5L8Xi81QJzB/nFbBL3ZISgKmlGg0OqWeq5J85wxzZeUb74okNtZP6/inuVqt/ qG1hgTmDIXLxLcFOUOdQ7SUgBUmu/CIy7jOF5XqXzJMA8+vN6mZCdxKS2JXX6aVz9ePqpV RHbeaUD9v3PgAt5Zaq7ZiypupNwl4XM= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5ch/QuOr2IZ30W763hH9kORlChf/b8rQ2pXYI9kCiyM=; b=Jg+7Mh/3ttDZ569MnI38xXsm2M KgOQL4twwfiN/0R2VTr8Q+E6Q7BG5RVG5PQ51jZaxo2UwDyWAtBoOngLa0nDD9UdOuk905yFNRJcx bP8twzpPWKr6Hz/hYDZNWZyxeB+4n12owINGX84Uej0E6eobHvVFkRCdDM6zNxNWwzI1017gEIfSr fA1Zs/7xWDwt/bH1Vg83A2Zc8GjiNrb3+5SHWd8MYFMRFknWwKUr6s9iG34Zfws4qzN5NovEv3O76 d0tHhIxq4NdfGSstfThJxzufIS6d3bgdvBLfeTeSgLfw4SydRopROv43UIDvNQSd3BIwH2xecBwFW N5VO2O9Q==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pf3WX-003Fix-V1; Wed, 22 Mar 2023 18:49:26 +0000 Date: Wed, 22 Mar 2023 18:49:25 +0000 From: Matthew Wilcox To: David Howells Cc: Trond Myklebust , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexander Viro , Christoph Hellwig , Jens Axboe , Jeffrey Layton , Christian Brauner , Linus Torvalds , "netdev@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Anna Schumaker , Charles Edward Lever , "linux-nfs@vger.kernel.org" Subject: Re: [RFC PATCH] iov_iter: Add an iterator-of-iterators Message-ID: References: <9C741BDB-31B0-460C-8FE7-F1C9B49002D5@hammerspace.com> <8F8B62FD-0F16-4383-BB34-97E850DAA7AF@hammerspace.com> <3DFBF27C-A62B-4AFE-87FD-3DF53FC39E8E@hammerspace.com> <20230316152618.711970-1-dhowells@redhat.com> <20230316152618.711970-28-dhowells@redhat.com> <754534.1678983891@warthog.procyon.org.uk> <809995.1678990010@warthog.procyon.org.uk> <3416400.1679508945@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3416400.1679508945@warthog.procyon.org.uk> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 7E6FE100003 X-Rspam-User: X-Stat-Signature: c9uctzkrikk4nex733wiepykniu15gju X-HE-Tag: 1679510980-987211 X-HE-Meta: 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 O+Ri7w4O GLjc3eJa70Gjtln0z8UVh//Iub9gJLrSQMU5AQYBu2n6ofvHubUuIFKbfTyKPomJEZulOrMt1SahCP+unm8MGKe2MS11v8jDDoRHqb6vqh4avymc/fa7t42PCKEMucd7XClv9T1Tf2Y6tPI2Ury8WSct2wznNzqu1u8MrT+3TsUirINkAk881Foc56bFGCSyaXsvalRxIkluCDAxqdsBnF5N73Wd+v3dkOchuuxlw2cYHiXavuoPABz2b6Q== 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 Wed, Mar 22, 2023 at 06:15:45PM +0000, David Howells wrote: > @@ -43,17 +44,17 @@ struct iov_iter { > bool nofault; > bool data_source; > bool user_backed; > - union { > - size_t iov_offset; > - int last_offset; > - }; > + bool spliceable; We've now up to five u8s in a row here (iter_type, nofault, data_source, user_backed). Is it time to turn some/all of them into: bool nofault:1; bool data_source:1; bool user_backed:1; bool spliceable:1; You can't take the address of them then, but I don't believe we do that anywhere.