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=-15.8 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,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 E51ACC43331 for ; Mon, 1 Mar 2021 15:13:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9D9264E2E for ; Mon, 1 Mar 2021 15:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237061AbhCAPMy (ORCPT ); Mon, 1 Mar 2021 10:12:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33752 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236962AbhCAPL1 (ORCPT ); Mon, 1 Mar 2021 10:11:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614611394; 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=TX+ZSUrgupzCs+dUOIxxKV7zfmeYVeA4M1/9UY7d40EryPp/Otsx5PfgnOLvAvhYdUkmuV hQM1qNLrMUOlRx3a6in+Id31F+1qYJGy2QK0OeZe1ed1ytUCPTGy4LnTk2fGbQCf9/f6fB dlH6FQ55WOsIG5IBQZT7ITH1LZyUX3w= 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 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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; } -- 2.29.2