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=-8.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 7AF92C31E49 for ; Thu, 13 Jun 2019 16:19:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 51FF020644 for ; Thu, 13 Jun 2019 16:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560442756; bh=6q88L9A9Pa+jImBbwyhfW8ejATVgHZx6mAgVsB1hBF8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KPjP1KxU0S4eRFQB466PdXlF2g772FDUCyo7R/71WyYn7eJa6BjloVObAytf8x78S ptQMtInXjDox4QlCza4D2wPMuj6kHiJ2lX0V7pujwtPXNgTitLMvovO6zARTymVw0Z JjhTo9W3vpzGuurUHw4h5VYnIc00Gu30QxfxzHEU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392053AbfFMQTK (ORCPT ); Thu, 13 Jun 2019 12:19:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:57442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731096AbfFMIj7 (ORCPT ); Thu, 13 Jun 2019 04:39:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7533F21473; Thu, 13 Jun 2019 08:39:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560415199; bh=6q88L9A9Pa+jImBbwyhfW8ejATVgHZx6mAgVsB1hBF8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j2k/Ygn47LobrPAwMJyikelZymuoh+UyqngzVqNqynjowBGYNHv+GQij1UzIbtXnB n2+KjNo27cEMwlPLUCUzNWEHxTOF/ADFPWMNZcx37GUtCzetf/YKSQ44LdQAqTC0r1 JpnqFDWXdmlpFjIjET/oqjeG6Rs/r2F/1utnzJA8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yue Hu , Andrew Morton , Joonsoo Kim , Ingo Molnar , Vlastimil Babka , Mike Rapoport , Randy Dunlap , Laura Abbott , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 012/118] mm/cma.c: fix the bitmap status to show failed allocation reason Date: Thu, 13 Jun 2019 10:32:30 +0200 Message-Id: <20190613075644.385271316@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190613075643.642092651@linuxfoundation.org> References: <20190613075643.642092651@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 2b59e01a3aa665f751d1410b99fae9336bd424e1 ] Currently one bit in cma bitmap represents number of pages rather than one page, cma->count means cma size in pages. So to find available pages via find_next_zero_bit()/find_next_bit() we should use cma size not in pages but in bits although current free pages number is correct due to zero value of order_per_bit. Once order_per_bit is changed the bitmap status will be incorrect. The size input in cma_debug_show_areas() is not correct. It will affect the available pages at some position to debug the failure issue. This is an example with order_per_bit = 1 Before this change: [ 4.120060] cma: number of available pages: 1@93+4@108+7@121+7@137+7@153+7@169+7@185+7@201+3@213+3@221+3@229+3@237+3@245+3@253+3@261+3@269+3@277+3@285+3@293+3@301+3@309+3@317+3@325+19@333+15@369+512@512=> 638 free of 1024 total pages After this change: [ 4.143234] cma: number of available pages: 2@93+8@108+14@121+14@137+14@153+14@169+14@185+14@201+6@213+6@221+6@229+6@237+6@245+6@253+6@261+6@269+6@277+6@285+6@293+6@301+6@309+6@317+6@325+38@333+30@369=> 252 free of 1024 total pages Obviously the bitmap status before is incorrect. Link: http://lkml.kernel.org/r/20190320060829.9144-1-zbestahu@gmail.com Signed-off-by: Yue Hu Reviewed-by: Andrew Morton Cc: Joonsoo Kim Cc: Ingo Molnar Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Randy Dunlap Cc: Laura Abbott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/cma.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index 6ce6e22f82d9..476dfe13a701 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -371,23 +371,26 @@ err: #ifdef CONFIG_CMA_DEBUG static void cma_debug_show_areas(struct cma *cma) { - unsigned long next_zero_bit, next_set_bit; + unsigned long next_zero_bit, next_set_bit, nr_zero; unsigned long start = 0; - unsigned int nr_zero, nr_total = 0; + unsigned long nr_part, nr_total = 0; + unsigned long nbits = cma_bitmap_maxno(cma); mutex_lock(&cma->lock); pr_info("number of available pages: "); for (;;) { - next_zero_bit = find_next_zero_bit(cma->bitmap, cma->count, start); - if (next_zero_bit >= cma->count) + next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start); + if (next_zero_bit >= nbits) break; - next_set_bit = find_next_bit(cma->bitmap, cma->count, next_zero_bit); + next_set_bit = find_next_bit(cma->bitmap, nbits, next_zero_bit); nr_zero = next_set_bit - next_zero_bit; - pr_cont("%s%u@%lu", nr_total ? "+" : "", nr_zero, next_zero_bit); - nr_total += nr_zero; + nr_part = nr_zero << cma->order_per_bit; + pr_cont("%s%lu@%lu", nr_total ? "+" : "", nr_part, + next_zero_bit); + nr_total += nr_part; start = next_zero_bit + nr_zero; } - pr_cont("=> %u free of %lu total pages\n", nr_total, cma->count); + pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count); mutex_unlock(&cma->lock); } #else -- 2.20.1