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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 521F0C4742C for ; Sat, 31 Oct 2020 21:33:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D0C5120731 for ; Sat, 31 Oct 2020 21:33:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="qGzJe2k7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D0C5120731 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A5E2B6B0036; Sat, 31 Oct 2020 17:33:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9E7BA6B005C; Sat, 31 Oct 2020 17:33:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 85F236B005D; Sat, 31 Oct 2020 17:33:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0041.hostedemail.com [216.40.44.41]) by kanga.kvack.org (Postfix) with ESMTP id 514626B0036 for ; Sat, 31 Oct 2020 17:33:54 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id EBC323629 for ; Sat, 31 Oct 2020 21:33:53 +0000 (UTC) X-FDA: 77433523146.02.anger71_3507478272a2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id CE2EB10097AA1 for ; Sat, 31 Oct 2020 21:33:53 +0000 (UTC) X-HE-Tag: anger71_3507478272a2 X-Filterd-Recvd-Size: 5937 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Sat, 31 Oct 2020 21:33:53 +0000 (UTC) Received: from mail-qk1-f180.google.com (mail-qk1-f180.google.com [209.85.222.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1DD53208A9 for ; Sat, 31 Oct 2020 21:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604180032; bh=a949fi3JWCiOsIfB/oXLlGSJaTnnNYCIyox+iEaG/3k=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=qGzJe2k7VxHxNGXm2ofy0cr987u/1eKUsypdKgkwKBMXCsccRZ8RcccNrMDFnu857 63dWT46wJ85+kA4RjachgCiYPBvsRc+x/36/Qnvv+xmd6BFdl2hNpg/ecIayEo6q1S tsohzNmLo8aEmGzBYbFk1H3mzIglUU1jWJGm6sf4= Received: by mail-qk1-f180.google.com with SMTP id z6so8324092qkz.4 for ; Sat, 31 Oct 2020 14:33:52 -0700 (PDT) X-Gm-Message-State: AOAM530GYKoGEnFuT1osqgGtUxuvzACs6APcy5ZPpyORTVCU4Dnx1ZAC i5PnuZMpWZMmP3wAIPCBrTqSTrkzAVb5Jn6dGe0= X-Google-Smtp-Source: ABdhPJyD/4AcE03j7HIaN207+kO4IYyQ0WkWkrWDUSbNUToIdPZlRv7YWwHuIabdMaXmtCngmEmV1ORQEwrjBUGk+Sk= X-Received: by 2002:ac8:4808:: with SMTP id g8mr8036830qtq.18.1604180029997; Sat, 31 Oct 2020 14:33:49 -0700 (PDT) MIME-Version: 1.0 References: <20201029221806.189523375@linutronix.de> <87pn50ob0s.fsf@nanos.tec.linutronix.de> <87blgknjcw.fsf@nanos.tec.linutronix.de> <87sg9vl59i.fsf@nanos.tec.linutronix.de> <20201031160539.Horde.n5yNbG9LoUSWqtuPQW_h3w1@messagerie.c-s.fr> In-Reply-To: <20201031160539.Horde.n5yNbG9LoUSWqtuPQW_h3w1@messagerie.c-s.fr> From: Arnd Bergmann Date: Sat, 31 Oct 2020 22:33:33 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends To: Christophe Leroy Cc: "David S. Miller" , Daniel Bristot de Oliveira , Andrew Morton , Paul Mackerras , Daniel Vetter , Arnd Bergmann , LKML , Vineet Gupta , Max Filippov , Nick Hu , Thomas Bogendoerfer , Michal Simek , Chris Zankel , Linux ARM , Dietmar Eggemann , Thomas Gleixner , Greentime Hu , Steven Rostedt , linuxppc-dev , Paul McKenney , Ard Biesheuvel , "open list:SYNOPSYS ARC ARCHITECTURE" , Mel Gorman , David Airlie , Christoph Hellwig , linux-csky@vger.kernel.org, Russell King , "the arch/x86 maintainers" , Herbert Xu , Vincent Guittot , linux-arch , Ingo Molnar , Vincent Chen , linux-sparc , Matthew Wilcox , Guo Ren , Linux-MM , Ben Segall , "open list:BROADCOM NVRAM DRIVER" , Sebastian Andrzej Siewior , Peter Zijlstra , linux-xtensa@linux-xtensa.org, Juri Lelli , Linus Torvalds Content-Type: text/plain; charset="UTF-8" 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 Sat, Oct 31, 2020 at 4:04 PM Christophe Leroy wrote: > > There are also some users on 10+ year old 32-bit netbooks or > > business laptops, both x86 and Apple G4. > > The longest-lived 32-bit embedded systems with large memory > > (other than Arm) are probably NXP QorIQ P20xx/P40xx used in > > military VME bus systems, and low-end embedded systems based > > on Vortex86. > > I'm less worried about all of these because upstream kernel > > support for ppc32 and x86-32 is already bitrotting and they will > > likely get stuck on the last working kernel before the > > TI/Renesas/NXP Arm systems do. > > > > Upstream kernel support for ppc32 is bitrotting, seriously ? What do > you mean exactly ? I was thinking more of the platform support: out of the twelve 32-bit platforms in arch/powerpc/platforms/, your 8xx is the only one listed as 'maintained' or 'supported' in the maintainers list, and that seems to accurately describe the current state. Freescale seems to have practically stopped contributing to any of their 32-bit platforms in 2016 after the NXP acquisition and no longer employing either of the maintainers. Similarly, Ben seems to have stopped working on powermac in 2016, which was ten years after the last 32-bit hardware shipped for that platform. > ppc32 is actively supported, with recent addition of support of > hugepages, kasan, uaccess protection, VMAP stack, etc ... That is good to hear, I didn't know about these additions. What platforms are people using to develop these? Is this mainly your 8xx work, or is there ongoing development for platforms that need highmem? Arnd