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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 2C4B7C2D0A3 for ; Wed, 4 Nov 2020 09:43:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 67B00223C7 for ; Wed, 4 Nov 2020 09:43:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 67B00223C7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8EF946B0036; Wed, 4 Nov 2020 04:43:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8A0926B005D; Wed, 4 Nov 2020 04:43:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 769C46B0068; Wed, 4 Nov 2020 04:43:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0191.hostedemail.com [216.40.44.191]) by kanga.kvack.org (Postfix) with ESMTP id 4AFC86B0036 for ; Wed, 4 Nov 2020 04:43:00 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E5A9E68BF for ; Wed, 4 Nov 2020 09:42:59 +0000 (UTC) X-FDA: 77446246878.28.word56_0409a94272c0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id C1DCA6C33 for ; Wed, 4 Nov 2020 09:42:59 +0000 (UTC) X-HE-Tag: word56_0409a94272c0 X-Filterd-Recvd-Size: 3122 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Nov 2020 09:42:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 268ECAF16; Wed, 4 Nov 2020 09:42:58 +0000 (UTC) Date: Wed, 4 Nov 2020 10:42:55 +0100 From: osalvador To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Rashmica Gupta , Andrew Morton , Mike Rapoport , Michal Hocko , Wei Yang Subject: Re: [PATCH v1 2/4] powerpc/mm: print warning in arch_remove_linear_mapping() Message-ID: <20201104094255.GA4981@localhost.localdomain> References: <20201029162718.29910-1-david@redhat.com> <20201029162718.29910-3-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201029162718.29910-3-david@redhat.com> 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 Thu, Oct 29, 2020 at 05:27:16PM +0100, David Hildenbrand wrote: > Let's print a warning similar to in arch_add_linear_mapping() instead of > WARN_ON_ONCE() and eventually crashing the kernel. > > Cc: Michael Ellerman > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Rashmica Gupta > Cc: Andrew Morton > Cc: Mike Rapoport > Cc: Michal Hocko > Cc: Oscar Salvador > Cc: Wei Yang > Signed-off-by: David Hildenbrand > --- > arch/powerpc/mm/mem.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index 8a86d81f8df0..685028451dd2 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -145,7 +145,9 @@ void __ref arch_remove_linear_mapping(u64 start, u64 size) > flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE); > > ret = remove_section_mapping(start, start + size); > - WARN_ON_ONCE(ret); > + if (ret) > + pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n", > + start, start + size, ret); I guess the fear is to panic on systems that do have panic_on_warn (not sure how many productions systems have this out there). But anyway, being coherent with that, I think you should remove the WARN_ON in hash__remove_section_mapping as well. Besides that: Reviewed-by: Oscar Salvador