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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3721AC43331 for ; Mon, 30 Mar 2020 17:08:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CC40A20776 for ; Mon, 30 Mar 2020 17:08:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC40A20776 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=SDF.ORG Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1F2698E0001; Mon, 30 Mar 2020 13:08:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 17C676B0037; Mon, 30 Mar 2020 13:08:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 01D2E8E0001; Mon, 30 Mar 2020 13:08:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id DB5066B0032 for ; Mon, 30 Mar 2020 13:08:43 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7613E8248047 for ; Mon, 30 Mar 2020 17:08:43 +0000 (UTC) X-FDA: 76652662926.12.step49_11df83e8f3f06 X-HE-Tag: step49_11df83e8f3f06 X-Filterd-Recvd-Size: 5184 Received: from mx.sdf.org (mx.sdf.org [205.166.94.20]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Mon, 30 Mar 2020 17:08:42 +0000 (UTC) Received: from sdf.org (IDENT:lkml@sdf.lonestar.org [205.166.94.16]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02UH3W3Y003279 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Mon, 30 Mar 2020 17:03:32 GMT Received: (from lkml@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02UH3Lda022564; Mon, 30 Mar 2020 17:03:21 GMT Date: Mon, 30 Mar 2020 17:03:21 +0000 From: George Spelvin To: Jan Kara Cc: linux-kernel@vger.kernel.org, Dave Hansen , Andy Lutomirski , Peter Zijlstra , Herbert Xu , "David S. Miller" , Atul Gupta , linux-crypto@vger.kernel.org, Doug Ledford , Jason Gunthorpe , Potnuri Bharat Teja , linux-rdma@vger.kernel.org, Ulf Hansson , linux-mmc@vger.kernel.org, Miquel Raynal , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Vignesh Raghavendra , Artem Bityutskiy , linux-mtd@lists.infradead.org, netdev@vger.kernel.org, Arend van Spriel , Franky Lin , Hante Meuleman , Chi-Hsien Lin , Wright Feng , brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com, Kalle Valo , Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , linux-wireless@vger.kernel.org, Hannes Reinecke , QLogic-Storage-Upstream@cavium.com, linux-scsi@vger.kernel.org, Jeff Layton , Sage Weil , Ilya Dryomov , ceph-devel@vger.kernel.org, Jan Kara , "Theodore Ts'o" , Andreas Dilger , linux-ext4@vger.kernel.org, Adrian Hunter , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Andrew Morton , linux-mm@kvack.org, Marek Lindner , Simon Wunderlich , Antonio Quartulli , Sven Eckelmann , b.a.t.m.a.n@diktynna.open-mesh.org, Alexey Kuznetsov , Hideaki YOSHIFUJI , Jamal Hadi Salim , Cong Wang , Jiri Pirko , Stephen Hemminger , netem@lists.linux-foundation.org, Vlad Yasevich , Neil Horman , Marcelo Ricardo Leitner , linux-sctp@vger.kernel.org, "J. Bruce Fields" , Chuck Lever , Trond Myklebust , Anna Schumaker , linux-nfs@vger.kernel.org, Jon Maloy , Ying Xue , tipc-discussion@lists.sourceforge.net, Steffen Klassert , lkml@sdf.org Subject: Re: [RFC PATCH v1 11/50] Treewide: Extirpate "prandom_u32() % range" Message-ID: <20200330170321.GC2459@SDF.ORG> References: <202003281643.02SGhAN9009531@sdf.org> <20200330133331.GB26544@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200330133331.GB26544@quack2.suse.cz> 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 Mon, Mar 30, 2020 at 03:33:31PM +0200, Jan Kara wrote: > Honestly, I think that a microoptimization like this will bring any benefit > only in the fast paths and e.g. most of the filesystem places aren't like > that as far as I've checked. OTOH it doesn't hurt readability so I'm not > opposed either. So feel free to add: > > Acked-by: Jan Kara > > for ext2 and ext4 bits. Thank you! I fully agree with you, but - Figuring out whether a particular site is a fast path or not is a lot more work than simply fixing it, - It's also smaller, which is what we care about for slow-path code. and - I wish people would stop copying the slow code to fast paths. If I make sure the kernel is full of good examples and devoid of bad examples, the odds improve.