From patchwork Mon Mar 1 15:09:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12109937 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C6222C433E0 for ; Mon, 1 Mar 2021 15:10:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5212C64DEF for ; Mon, 1 Mar 2021 15:10:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5212C64DEF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D6B9C8D0078; Mon, 1 Mar 2021 10:09:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D19B58D0063; Mon, 1 Mar 2021 10:09:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C2EC98D0078; Mon, 1 Mar 2021 10:09:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0076.hostedemail.com [216.40.44.76]) by kanga.kvack.org (Postfix) with ESMTP id AB6D48D0063 for ; Mon, 1 Mar 2021 10:09:59 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 73995824999B for ; Mon, 1 Mar 2021 15:09:59 +0000 (UTC) X-FDA: 77871640518.13.BE49ED6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf03.hostedemail.com (Postfix) with ESMTP id EF45BC000C6F for ; Mon, 1 Mar 2021 15:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614611397; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sii7nAfrV7srStWfit5QssGqQJ5z5OEblPF7nTrmNeM=; b=NdzpcVgza/yrk2MO2EDwggwvK0vGzUFHpevjjINYrn8zyGiDfV+F2rDkbViV0Ek2yiBaw8 ZLt0N4uBIMlAMoLs3Ewu/kiSBUPfS2XYwisorbNhXw0Y1OfhD3r+KzfesLr2B0a4gaEP3g FfZhiqHrgdrFALArxuF92TZyDJWWMok= 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-335-qe_9k3zCNJK5Ejpi3ohs0g-1; Mon, 01 Mar 2021 10:09:52 -0500 X-MC-Unique: qe_9k3zCNJK5Ejpi3ohs0g-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 025E91005501; Mon, 1 Mar 2021 15:09:51 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-87.ams2.redhat.com [10.36.114.87]) by smtp.corp.redhat.com (Postfix) with ESMTP id E08355C3E5; Mon, 1 Mar 2021 15:09:45 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Andrew Morton , Minchan Kim , Oscar Salvador , Michal Hocko , Vlastimil Babka Subject: [PATCH v1] mm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range() Date: Mon, 1 Mar 2021 16:09:45 +0100 Message-Id: <20210301150945.77012-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Stat-Signature: f3piskcbh9hypa34re37jgjx696dm5nz X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: EF45BC000C6F Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf03; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=216.205.24.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614611394-50109 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: The information that some PFNs are busy is: a) not helpful for ordinary users: we don't even know *who* called alloc_contig_range(). This is certainly not worth a pr_info.*(). b) not really helpful for debugging: we don't have any details *why* these PFNs are busy, and that is what we usually care about. c) not complete: there are other cases where we fail alloc_contig_range() using different paths that are not getting recorded. For example, we reach this path once we succeeded in isolating pageblocks, but failed to migrate some pages - which can happen easily on ZONE_NORMAL (i.e., has_unmovable_pages() is racy) but also on ZONE_MOVABLE i.e., we would have to retry longer to migrate). For example via virtio-mem when unplugging memory, we can create quite some noise (especially with ZONE_NORMAL) that is not of interest to users - it's expected that some allocations may fail as memory is busy. Let's just drop that pr_info_ratelimit() and rather implement a dynamic debugging mechanism in the future that can give us a better reason why alloc_contig_range() failed on specific pages. Cc: Andrew Morton Cc: Minchan Kim Cc: Oscar Salvador Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Acked-by: Michal Hocko Reviewed-by: Oscar Salvador --- mm/page_alloc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 519a60d5b6f7..efb924fb13e8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8647,8 +8647,6 @@ int alloc_contig_range(unsigned long start, unsigned long end, /* Make sure the range is really isolated. */ if (test_pages_isolated(outer_start, end, 0)) { - pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n", - __func__, outer_start, end); ret = -EBUSY; goto done; }