From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761624AbZLJTpO (ORCPT ); Thu, 10 Dec 2009 14:45:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761567AbZLJTpN (ORCPT ); Thu, 10 Dec 2009 14:45:13 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:51957 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761101AbZLJTpL (ORCPT ); Thu, 10 Dec 2009 14:45:11 -0500 Date: Thu, 10 Dec 2009 20:45:09 +0100 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Andrew Morton Subject: [GIT PULL] locking fixes Message-ID: <20091210194509.GA7463@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest core-fixes-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core-fixes-for-linus Thanks, Ingo ------------------> Andi Kleen (1): futex: Take mmap_sem for get_user_pages in fault_in_user_writeable Frank Rowand (2): lockstat: Fix min, max times in /proc/lock_stats lockstat: Add usage info to Documentation/lockstat.txt Tony Luck (1): lockdep: Avoid out of bounds array reference in save_trace() Documentation/lockstat.txt | 12 ++++++++++++ kernel/futex.c | 10 ++++++++-- kernel/lockdep.c | 16 ++++++++++++---- 3 files changed, 32 insertions(+), 6 deletions(-) diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt index 9cb9138..65f4c79 100644 --- a/Documentation/lockstat.txt +++ b/Documentation/lockstat.txt @@ -62,8 +62,20 @@ applicable). It also tracks 4 contention points per class. A contention point is a call site that had to wait on lock acquisition. + - CONFIGURATION + +Lock statistics are enabled via CONFIG_LOCK_STATS. + - USAGE +Enable collection of statistics: + +# echo 1 >/proc/sys/kernel/lock_stat + +Disable collection of statistics: + +# echo 0 >/proc/sys/kernel/lock_stat + Look at the current lock statistics: ( line numbers not part of actual output, done for clarity in the explanation diff --git a/kernel/futex.c b/kernel/futex.c index fb65e82..d73ef1f 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -304,8 +304,14 @@ void put_futex_key(int fshared, union futex_key *key) */ static int fault_in_user_writeable(u32 __user *uaddr) { - int ret = get_user_pages(current, current->mm, (unsigned long)uaddr, - 1, 1, 0, NULL, NULL); + struct mm_struct *mm = current->mm; + int ret; + + down_read(&mm->mmap_sem); + ret = get_user_pages(current, mm, (unsigned long)uaddr, + 1, 1, 0, NULL, NULL); + up_read(&mm->mmap_sem); + return ret < 0 ? ret : 0; } diff --git a/kernel/lockdep.c b/kernel/lockdep.c index f5dcd36..4f8df01 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -168,7 +168,7 @@ static void lock_time_inc(struct lock_time *lt, u64 time) if (time > lt->max) lt->max = time; - if (time < lt->min || !lt->min) + if (time < lt->min || !lt->nr) lt->min = time; lt->total += time; @@ -177,8 +177,15 @@ static void lock_time_inc(struct lock_time *lt, u64 time) static inline void lock_time_add(struct lock_time *src, struct lock_time *dst) { - dst->min += src->min; - dst->max += src->max; + if (!src->nr) + return; + + if (src->max > dst->max) + dst->max = src->max; + + if (src->min < dst->min || !dst->nr) + dst->min = src->min; + dst->total += src->total; dst->nr += src->nr; } @@ -379,7 +386,8 @@ static int save_trace(struct stack_trace *trace) * complete trace that maxes out the entries provided will be reported * as incomplete, friggin useless */ - if (trace->entries[trace->nr_entries-1] == ULONG_MAX) + if (trace->nr_entries != 0 && + trace->entries[trace->nr_entries-1] == ULONG_MAX) trace->nr_entries--; trace->max_entries = trace->nr_entries;