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Rozycki" Cc: "Linus Torvalds" , "Matthew Wilcox" , "Peter Zijlstra" , "the arch/x86 maintainers" , "Yu Zhao" , "Andrew Morton" , "Andi Kleen" , "Aneesh Kumar" , "Catalin Marinas" , "Dave Hansen" , "Hillf Danton" , "Jens Axboe" , "Johannes Weiner" , "Jonathan Corbet" , "Mel Gorman" , "Michael Larabel" , "Michal Hocko" , "Mike Rapoport" , "Tejun Heo" , "Vlastimil Babka" , "Will Deacon" , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, page-reclaim@google.com, "Brian Geffon" , "Jan Alexander Steffens" , "Oleksandr Natalenko" , "Steven Barrett" , "Suleiman Souhlal" , "Daniel Byrne" , "Donald Carr" , =?UTF-8?Q?Holger_Hoffst=C3=A4tte?= , "Konstantin Kharlamov" , "Shuang Zhai" , "Sofia Trinh" , "Vaibhav Jain" Subject: Re: [PATCH v14 08/14] mm: multi-gen LRU: support page table walks Content-Type: text/plain ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=arndb.de header.s=fm2 header.b=d01UbbMY; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=OLuOC43S; spf=pass (imf11.hostedemail.com: domain of arnd@arndb.de designates 66.111.4.28 as permitted sender) smtp.mailfrom=arnd@arndb.de; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666942095; a=rsa-sha256; cv=none; b=wKNa1R3OMIdtVk6HSu+x8FDsbBWg/0Qrb5Pxuf//xh5DHWpNbNBwOVeJWxicl0RoED3lRf ONUKerOyjZfAy4U+2pYYEXu67nYcS/wXMh3hOAnt7fsnRvgQ8qfvcQU+rKW7ZQFpZtswyr FXHrpb+pDqa6jySmCEORNg50MOQHxXE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666942095; 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=J26rTTCqak8NzMmZtDK4DJgyNSOzQar/SiCpEkw2BSI=; b=AuAf/ekO1xgpuHxAvfuiJLgnmp6RHOX3qOpFJ/vDMQjWZytKBJUxr+7C1J1PAkD3tQpaJu iQauV6M1a/uLlyy5hQlLYKpcS0P4fwHYNCecpQLG7OgRik7YZkFMEyGtfNlzh60dhjl82Q W3MbNyFLbTwrWgMyzIe7AC4BW0XtbP0= X-Rspam-User: X-Rspamd-Queue-Id: CB7344000B Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=arndb.de header.s=fm2 header.b=d01UbbMY; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=OLuOC43S; spf=pass (imf11.hostedemail.com: domain of arnd@arndb.de designates 66.111.4.28 as permitted sender) smtp.mailfrom=arnd@arndb.de; dmarc=none X-Stat-Signature: xofdhxszj5yji66gppkbodisjg9yhmrx X-Rspamd-Server: rspam10 X-HE-Tag: 1666942094-432741 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, Oct 28, 2022, at 01:08, Maciej W. Rozycki wrote: > On Wed, 26 Oct 2022, Arnd Bergmann wrote: >> - For the special case of early ARMv6 hardware that has 32-bit >> atomics but not 64-bit ones, the kernel just falls back to >> CONFIG_GENERIC_ATOMIC64 and no cmpxchg64(). The same should work >> for an i486+SMP kernel. It's obviously slower, but most users >> can trivially avoid this by either running an i686 SMP kernel >> or an i486 UP kernel. > > You meant an M586TSC+ SMP kernel presumably (I have such a machine), but > otherwise I'd be fine with such an approach too. Sure. I just gave i686 as the example since that's already the baseline in 90% of the remaining x86-32 distros. Slackware, ALT and Mageia are notable exceptions that target i586, and some others already have separate installers for i486 and i686. The i586 distros all seem to have separate SMP/PAE kernels in addition to the minimal i586. Arnd