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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 C51E9C43461 for ; Fri, 30 Apr 2021 06:01:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1C9361482 for ; Fri, 30 Apr 2021 06:01:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230296AbhD3GBr (ORCPT ); Fri, 30 Apr 2021 02:01:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:54954 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230229AbhD3GBq (ORCPT ); Fri, 30 Apr 2021 02:01:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F21076148E; Fri, 30 Apr 2021 06:00:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1619762459; bh=ec1vlDoTFvTi5qGapLJKPLvC7NACFjIZUb9h/vove0M=; h=Date:From:To:Subject:In-Reply-To:From; b=WzGpplFyEOlSukbVJwGIQ5POspErd3wdg5jrt23/w9IWyO4Pnnkh92VnT2iXASaV8 V1nBmZapYLm+wXMq2VmmZ1ZRZnLXGosHQxtrlITXQuXjQOlbwRxEYW43Lyf267mgJb a5aNTSpeYB2IcRXasWHRKKTokGFl/s7BKROpj6qU= Date: Thu, 29 Apr 2021 23:00:58 -0700 From: Andrew Morton To: akpm@linux-foundation.org, david@redhat.com, linux-mm@kvack.org, mhocko@suse.com, minchan@kernel.org, mm-commits@vger.kernel.org, osalvador@suse.de, torvalds@linux-foundation.org, vbabka@suse.cz, ziy@nvidia.com Subject: [patch 151/178] mm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range() Message-ID: <20210430060058.yH9dS1Mpv%akpm@linux-foundation.org> In-Reply-To: <20210429225251.02b6386d21b69255b4f6c163@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: David Hildenbrand Subject: mm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range() 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. Link: https://lkml.kernel.org/r/20210301150945.77012-1-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Acked-by: Michal Hocko Reviewed-by: Oscar Salvador Acked-by: Minchan Kim Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/page_alloc.c | 2 -- 1 file changed, 2 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-drop-pr_info_ratelimited-in-alloc_contig_range +++ a/mm/page_alloc.c @@ -8676,8 +8676,6 @@ int alloc_contig_range(unsigned long sta /* 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; } _