From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1035167AbcIWSUd (ORCPT ); Fri, 23 Sep 2016 14:20:33 -0400 Received: from sender153-mail.zoho.com ([74.201.84.153]:25471 "EHLO sender153-mail.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1034106AbcIWSUb (ORCPT ); Fri, 23 Sep 2016 14:20:31 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=cc:to:from:subject:message-id:date:user-agent:mime-version:content-type; b=dLTAUAVeXm/kF/BM0Yox5V3F3KYWyoyhcRRC9cXO+Oxq92gQgi9lh/HZ15BzpQE7bMNF6vur9MJS HlysKh7rNvOFy6VviEgz7dljx7DPlkGJYcm+BBZV4mkVBtxMahyb Cc: zijun_hu@htc.com, "linux-kernel@vger.kernel.org" , linux-mm@kvack.org, cl@linux.com To: Tejun Heo , Andrew Morton From: zijun_hu Subject: [PATCH 1/1] mm/percpu.c: correct max_distance calculation for pcpu_embed_first_chunk() Message-ID: <7180d3c9-45d3-ffd2-cf8c-0d925f888a4d@zoho.com> Date: Sat, 24 Sep 2016 02:20:24 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zijun_hu correct max_distance from (base of the highest group + ai->unit_size) to (base of the highest group + the group size) Signed-off-by: zijun_hu --- mm/percpu.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/percpu.c b/mm/percpu.c index fcaaac977954..ee0d1c93f070 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1963,7 +1963,8 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, void *base = (void *)ULONG_MAX; void **areas = NULL; struct pcpu_alloc_info *ai; - size_t size_sum, areas_size, max_distance; + size_t size_sum, areas_size; + unsigned long max_distance; int group, i, rc; ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, @@ -2025,17 +2026,18 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, } /* base address is now known, determine group base offsets */ - max_distance = 0; + i = 0; for (group = 0; group < ai->nr_groups; group++) { ai->groups[group].base_offset = areas[group] - base; - max_distance = max_t(size_t, max_distance, - ai->groups[group].base_offset); + if (areas[group] > areas[i]) + i = group; } - max_distance += ai->unit_size; + max_distance = ai->groups[i].base_offset + + (unsigned long)ai->unit_size * ai->groups[i].nr_units; /* warn if maximum distance is further than 75% of vmalloc space */ if (max_distance > VMALLOC_TOTAL * 3 / 4) { - pr_warn("max_distance=0x%zx too large for vmalloc space 0x%lx\n", + pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n", max_distance, VMALLOC_TOTAL); #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK /* and fail if we have fallback */ -- 1.9.1