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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B08E5C07E95 for ; Tue, 13 Jul 2021 08:54:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 928EA61351 for ; Tue, 13 Jul 2021 08:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234690AbhGMI5L (ORCPT ); Tue, 13 Jul 2021 04:57:11 -0400 Received: from verein.lst.de ([213.95.11.211]:57811 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234599AbhGMI5L (ORCPT ); Tue, 13 Jul 2021 04:57:11 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id D941C67373; Tue, 13 Jul 2021 10:54:19 +0200 (CEST) Date: Tue, 13 Jul 2021 10:54:19 +0200 From: Christoph Hellwig To: Michael Schmitz Cc: Christoph Hellwig , Andreas Schwab , Geert Uytterhoeven , Greg Ungerer , linux-m68k@lists.linux-m68k.org Subject: Re: RFC: remove set_fs for m68k Message-ID: <20210713085419.GA22839@lst.de> References: <20210709070132.3387689-1-hch@lst.de> <039e2f42-b9bc-d8ce-393a-c0896439f784@gmail.com> <87fswjomtm.fsf@igel.home> <969718aa-92d4-e77b-0630-f9da6c809178@gmail.com> <20210713054134.GA5880@lst.de> <90e30f50-f062-ac8d-68e7-1250c886d0e1@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <90e30f50-f062-ac8d-68e7-1250c886d0e1@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org On Tue, Jul 13, 2021 at 08:16:25PM +1200, Michael Schmitz wrote: > I'll try that next. It certainly ran fine when I tried your earlier version > which still had the __constant_copy_from_user() (but modified to use > __get_user_asm() for the 1, 2 and 4 byte cases). That doesn't prove much > though - I may not have hit the exact same memory pressure (not sure how > often savelogs runs on that system, and I haven't checked how much the > kernel size differs between the two versions). > > Anyway, I'll try my previous version again, and I'll try with the WARN_ON > removed, but that'll take a few days (did I mention this 030 is clocked at > 16 MHz only?). No problem. > I suspect it may get called from an interrupt - not sure what interrupt > handler would call vm_map_ram(), or if that even is allowed though. Might > happen during a softirq, which is covered by in_interrupt as well ... vm_map_ram isn't allowed to be called from interrupts, just like all the vmalloc/vmap code. But that doesn't mean it might not have crept in somewhere.