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 4AF4FC00140 for ; Sat, 6 Aug 2022 01:43:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 326326B0071; Fri, 5 Aug 2022 21:43:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D4B06B0072; Fri, 5 Aug 2022 21:43:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1EB078E0001; Fri, 5 Aug 2022 21:43:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 107BF6B0071 for ; Fri, 5 Aug 2022 21:43:36 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id D6A9C1606F1 for ; Sat, 6 Aug 2022 01:43:35 +0000 (UTC) X-FDA: 79767470790.01.F43AC81 Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by imf15.hostedemail.com (Postfix) with ESMTP id 74FE0A0138 for ; Sat, 6 Aug 2022 01:43:35 +0000 (UTC) Received: from omf13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 8EF7A406F2; Sat, 6 Aug 2022 01:43:34 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf13.hostedemail.com (Postfix) with ESMTPA id C544920010; Sat, 6 Aug 2022 01:43:32 +0000 (UTC) Message-ID: <12695fa86c0e3e062077b5e11a66234d9404e4a2.camel@perches.com> Subject: Re: [GIT PULL] MM updates for 5.20-rc1 From: Joe Perches To: Andrew Morton , Roman Gushchin Cc: Linus Torvalds , Kent Overstreet , mm-commits@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Chinner Date: Fri, 05 Aug 2022 18:43:32 -0700 In-Reply-To: <20220805170752.d609551360017d60903e5e75@linux-foundation.org> References: <20220803133541.18b82ec9344ed0e8b975fe5b@linux-foundation.org> <20220805170752.d609551360017d60903e5e75@linux-foundation.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.1-0ubuntu1 MIME-Version: 1.0 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX1/PQT5mEc4qSatyOMKaUxBPL8ydPsKALW0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659750215; 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; bh=9o6mnoHNcMJEZMz+runQ24xyja4nmNd6y9msxp/eUPU=; b=qxB/vs9uZfntEDuvBXVuvn2xfK2e1eq9AdnGiCO6lURb6htjvJTTkLVVESbUGONPD0cjVa wrKhtEGqpElRIKWqzzLOCLyBiWWdmplsyLduma7RF56/pqlDcCn/BCshe8S3YND36TdOS7 IzHtbsO5Fh0B9IRi05kPbhumMLCycFA= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=none; spf=none (imf15.hostedemail.com: domain of joe@perches.com has no SPF policy when checking 216.40.44.12) smtp.mailfrom=joe@perches.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659750215; a=rsa-sha256; cv=none; b=5JBX9EtfL9bYvfD7iS2x09QkM9ETNNUZVA2xOrKPuSI/jtLFRyGrnHQeRRHlX6mbT/nU0H NSXliYm4rR7AHXdhFupnTEBJbXg5a+wDo7EGkAKQAr+0YVBDXve9gNef6Zj5oCewYPt03d UI/0FNl7zSLiu+KH1Qz0WmeXkI8MAJg= X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=none; spf=none (imf15.hostedemail.com: domain of joe@perches.com has no SPF policy when checking 216.40.44.12) smtp.mailfrom=joe@perches.com; dmarc=none X-HE-Tag-Orig: 1659750212-509346 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 74FE0A0138 X-Stat-Signature: e6zqe6ami4c89drkrdowk3dxx6b6n5ro X-HE-Tag: 1659750215-943057 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 Fri, 2022-08-05 at 17:07 -0700, Andrew Morton wrote: > On Fri, 5 Aug 2022 17:04:28 -0700 Roman Gushchin wrote: >=20 > > On Fri, Aug 05, 2022 at 04:32:34PM -0700, Linus Torvalds wrote: > > > On Wed, Aug 3, 2022 at 1:35 PM Andrew Morton wrote: > > > >=20 > > > > - memcg debug/visibility work from Roman Gushchin > > >=20 > > > Well, not just memcg. > > >=20 > > > There's that new CONFIG_SHRINKER_DEBUG too. > > >=20 > > > Which looks like yet another "people add Kconfig options incorrectly"= . > > >=20 > > > We don't make new features "default y" unless there's some truly > > > pressing reason for it (ie "99.9% of all people will want this" or "w= e > > > used to always compile this in, now it's optional"). > >=20 > > Hi Linus! > >=20 > > It actually was 'default n' in one of the earlier version of the patchs= et > > and has been switched to 'default y' based on the following feedback fr= om > > Dave Chinner (https://lore.kernel.org/lkml/YmiWK56bOHyrr64u@rh/): > >=20 > > No. The argument that "if we turn it off there's no overhead" means > > one of two things: > >=20 > > 1. nobody turns it on and it never gets tested and so bitrots and i= s > > useless, or > > 2. distro's all turn it on because some tool they ship or customer > > they ship to wants it. > >=20 > > Either way, hiding it behind a config option is not an acceptible > > solution for mering poorly thought out infrastructure. > >=20 > > Personally I think that the feature is not that useful for the majority > > of users (this is why default was n), but it's not adding much of the > > overhead, so I had no strong reasons to oppose Dave. > > Cc'ing him just in case. > >=20 >=20 > We should have changelogged these considerations. >=20 > I've asked Joe if checkpatch can get a "default y" detector, to draw > attention to this in the future. Perhaps: --- scripts/checkpatch.pl | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index bf7c5abeefaad..1abec0cd217e6 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -3523,6 +3523,19 @@ sub process { } } =20 +# check new Kconfig entries for default=3Dy +# Only applies when adding the entry originally and if the entry is not +# conditional on anything like default y if + if ($realfile =3D~ /Kconfig/ && + !$file && + $line =3D~ /\+\s*default\s+y\s*$/i) { + if (WARN("KCONFIG_DEFAULT_Y", + "Kconfig entries should generally not be default y\n" . $herecurr) && + $fix) { + $fixed[$fixlinenr] =3D~ s/default(\s+)y/default${1}n/; + } + } + # check MAINTAINERS entries if ($realfile =3D~ /^MAINTAINERS$/) { # check MAINTAINERS entries for the right form