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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 A69D5C28CC1 for ; Sat, 1 Jun 2019 13:17:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D2C527251 for ; Sat, 1 Jun 2019 13:17:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559395076; bh=B1J+LEftpT2eJ8CNTcSUayV3uaqVgtvofuMySmehwFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tNcJRTARePsPJCSre7AhuzfZS3vcCei08P9gJSSCimNNQByBwZLKyQDVeVsWtkjG+ SUaqaVqWyqSQ0C1xOv5pz4w2kg8HQs9vp8MPHdHxExuVfSo/dHtW8kTwFx9wxt38BB 9SoNTOPMJW0fLOGhRAic+P98RZXJk0Tli26bX8vs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727607AbfFANRz (ORCPT ); Sat, 1 Jun 2019 09:17:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:44758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727585AbfFANRy (ORCPT ); Sat, 1 Jun 2019 09:17:54 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 73ADA25525; Sat, 1 Jun 2019 13:17:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559395072; bh=B1J+LEftpT2eJ8CNTcSUayV3uaqVgtvofuMySmehwFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sHpNuSFmbOrn9rekG1Bxye6ZCyacrs1xTNf9ToWq/Q+2yH3VvdETLwL53F/4pqw11 2igMUZT07ZGcb4KAO0LNC3L6PTQLvJ7/cr6iElTh1fTvrnCWybfWKuUAv8uFj8mZRo 2IX5VH3/44iwzPs52VgK8Es6tnUm6uPKduaKCUgk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yue Hu , Andrew Morton , Joonsoo Kim , Ingo Molnar , Vlastimil Babka , Mike Rapoport , Randy Dunlap , Laura Abbott , Linus Torvalds , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.1 019/186] mm/cma.c: fix the bitmap status to show failed allocation reason Date: Sat, 1 Jun 2019 09:13:55 -0400 Message-Id: <20190601131653.24205-19-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190601131653.24205-1-sashal@kernel.org> References: <20190601131653.24205-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yue Hu [ 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 8cb95cd1193a9..5e36d7418031c 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -369,23 +369,26 @@ int __init cma_declare_contiguous(phys_addr_t base, #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