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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 03336C388F9 for ; Mon, 23 Nov 2020 14:08:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4D022075A for ; Mon, 23 Nov 2020 14:08:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TR9LFZA/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729845AbgKWOI0 (ORCPT ); Mon, 23 Nov 2020 09:08:26 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:50221 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729652AbgKWOIZ (ORCPT ); Mon, 23 Nov 2020 09:08:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606140504; h=from:from: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=hUFzzbljONitOgcLEsp2ObXM969hWXj1Vl6yGCwoRQg=; b=TR9LFZA/b1sKHRWBbK+q/6lwf2REia7mug2Tegn4vyWSSpw1K4cGSzJ0vREx/Qa+XvZEBf Ku+hLvJawqRUnrnVLMdZ09QOn93yxJ+D3CctE516p+hXVKelmLBHkCm60QBPpS40fAcxav ybe2Jk2A7ijE6mnnlYfDxDv1NfMKaKY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-13-VQsyr_QwP4-uPr5e20dvKg-1; Mon, 23 Nov 2020 09:08:19 -0500 X-MC-Unique: VQsyr_QwP4-uPr5e20dvKg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6456C1005E48; Mon, 23 Nov 2020 14:08:18 +0000 (UTC) Received: from [10.36.114.57] (ovpn-114-57.ams2.redhat.com [10.36.114.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 46E7960864; Mon, 23 Nov 2020 14:08:17 +0000 (UTC) Subject: Re: [PATCH] mm: memory_hotplug: put migration failure information under DEBUG_VM To: Charan Teja Reddy , akpm@linux-foundation.org, mhocko@suse.com, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org References: <1606140196-6053-1-git-send-email-charante@codeaurora.org> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <9e2b8ee5-62b5-4f38-207e-b68b615e304d@redhat.com> Date: Mon, 23 Nov 2020 15:08:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <1606140196-6053-1-git-send-email-charante@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23.11.20 15:03, Charan Teja Reddy wrote: > When the pages are failed to get isolate or migrate, the page owner > information along with page info is dumped. If there are continuous > failures in migration(say page is pinned) or isolation, the log buffer > is simply getting flooded with the page owner information. As most of > the times page info is sufficient to know the causes for failures of > migration or isolation, place the page owner information under DEBUG_VM. > > Signed-off-by: Charan Teja Reddy > --- > mm/memory_hotplug.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 63b2e46..f48f30d 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1326,7 +1326,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > > } else { > pr_warn("failed to isolate pfn %lx\n", pfn); > - dump_page(page, "isolation failed"); > + __dump_page(page, "isolation failed"); > +#if defined(CONFIG_DEBUG_VM) > + dump_page_owner(page); > +#endif > } > put_page(page); > } > @@ -1357,7 +1360,10 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > list_for_each_entry(page, &source, lru) { > pr_warn("migrating pfn %lx failed ret:%d ", > page_to_pfn(page), ret); > - dump_page(page, "migration failure"); > + __dump_page(page, "migration failure"); > +#if defined(CONFIG_DEBUG_VM) > + dump_page_owner(page); > +#endif > } > putback_movable_pages(&source); > } > It might also make sense to provide an explicit opt-in whether to pr_warn/dump at all. Most user simply don't care, yet dmesg gets flooded. Acked-by: David Hildenbrand -- Thanks, David / dhildenb