Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751667Ab3FJG3U (ORCPT ); Mon, 10 Jun 2013 02:29:20 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:24299 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751108Ab3FJG3R (ORCPT ); Mon, 10 Jun 2013 02:29:17 -0400 From: Yinghai Lu To: "H. Peter Anvin" , Andrew Morton Cc: Thomas Gleixner , Ingo Molnar , Joshua Covington , linux-kernel@vger.kernel.org, Yinghai Lu , Subject: [PATCH v2 2/2] x86, range: Do not add new blank slot with add_range_with_merge Date: Sun, 9 Jun 2013 23:29:02 -0700 Message-Id: <1370845742-18919-1-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.8.1.4 X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2256 Lines: 68 Joshua reported: Commit cd7b304dfaf1 (x86, range: fix missing merge during add range) broke mtrr cleanup on his setup in 3.9.5. corresponding commit in upstream is fbe06b7bae7c. The reason is add_range_with_merge could generate blank spot. We could avoid that by searching new expanded start/end, that new range should include all connected ranges in range array. At last add the new expanded start/end to the range array. Also move up left array so do not add new blank slot in the range array. -v2: move left array to avoid enhance add_range() Reported-by: Joshua Covington Signed-off-by: Yinghai Lu Cc: v3.9 --- arch/x86/kernel/cpu/mtrr/cleanup.c | 2 +- kernel/range.c | 21 +++++++++++---------- 2 files changed, 12 insertions(+), 11 deletions(-) Index: linux-2.6/kernel/range.c =================================================================== --- linux-2.6.orig/kernel/range.c +++ linux-2.6/kernel/range.c @@ -32,9 +32,8 @@ int add_range_with_merge(struct range *r if (start >= end) return nr_range; - /* Try to merge it with old one: */ + /* get new start/end: */ for (i = 0; i < nr_range; i++) { - u64 final_start, final_end; u64 common_start, common_end; if (!range[i].end) @@ -45,14 +44,16 @@ int add_range_with_merge(struct range *r if (common_start > common_end) continue; - final_start = min(range[i].start, start); - final_end = max(range[i].end, end); - - /* clear it and add it back for further merge */ - range[i].start = 0; - range[i].end = 0; - return add_range_with_merge(range, az, nr_range, - final_start, final_end); + /* new start/end, will add it back at last */ + start = min(range[i].start, start); + end = max(range[i].end, end); + + memmove(&range[i], &range[i + 1], + (nr_range - (i + 1)) * sizeof(range[i])); + range[nr_range - 1].start = 0; + range[nr_range - 1].end = 0; + nr_range--; + i--; } /* Need to add it: */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/