[PATCH 3/4] add new lock ordering rule to mm/filemap.c

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From: Dean Nelson <dcn@sgi.com>
To: akpm@linux-foundation.org
Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, tony.luck@intel.com, jes@sgi.com
Subject: [PATCH 3/4] add new lock ordering rule to mm/filemap.c
Date: Mon, 27 Aug 2007 16:02:48 +0000	[thread overview]
Message-ID: <20070827160247.GD25589@sgi.com> (raw)
In-Reply-To: <20070827155622.GA25589@sgi.com>

This patch adds a lock ordering rule to avoid a potential deadlock when
multiple mmap_sems need to be locked.

Signed-off-by: Dean Nelson <dcn@sgi.com>

Index: linux-2.6/mm/filemap.c
=================================--- linux-2.6.orig/mm/filemap.c	2007-08-09 19:18:15.000000000 -0500
+++ linux-2.6/mm/filemap.c	2007-08-27 09:13:47.435717670 -0500
@@ -78,6 +78,9 @@
  *  ->i_mutex			(generic_file_buffered_write)
  *    ->mmap_sem		(fault_in_pages_readable->do_page_fault)
  *
+ *    When taking multiple mmap_sems, one should lock the lowest-addressed
+ *    one first proceeding on up to the highest-addressed one.
+ *
  *  ->i_mutex
  *    ->i_alloc_sem             (various)
  *

WARNING: multiple messages have this Message-ID (diff)

From: Dean Nelson <dcn@sgi.com>
To: akpm@linux-foundation.org
Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, tony.luck@intel.com, jes@sgi.com
Subject: [PATCH 3/4] add new lock ordering rule to mm/filemap.c
Date: Mon, 27 Aug 2007 11:02:48 -0500	[thread overview]
Message-ID: <20070827160247.GD25589@sgi.com> (raw)
In-Reply-To: <20070827155622.GA25589@sgi.com>

This patch adds a lock ordering rule to avoid a potential deadlock when
multiple mmap_sems need to be locked.

Signed-off-by: Dean Nelson <dcn@sgi.com>

Index: linux-2.6/mm/filemap.c
===================================================================
--- linux-2.6.orig/mm/filemap.c	2007-08-09 19:18:15.000000000 -0500
+++ linux-2.6/mm/filemap.c	2007-08-27 09:13:47.435717670 -0500
@@ -78,6 +78,9 @@
  *  ->i_mutex			(generic_file_buffered_write)
  *    ->mmap_sem		(fault_in_pages_readable->do_page_fault)
  *
+ *    When taking multiple mmap_sems, one should lock the lowest-addressed
+ *    one first proceeding on up to the highest-addressed one.
+ *
  *  ->i_mutex
  *    ->i_alloc_sem             (various)
  *

WARNING: multiple messages have this Message-ID (diff)

From: Dean Nelson <dcn@sgi.com>
To: akpm@linux-foundation.org
Cc: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, tony.luck@intel.com, jes@sgi.com
Subject: [PATCH 3/4] add new lock ordering rule to mm/filemap.c
Date: Mon, 27 Aug 2007 11:02:48 -0500	[thread overview]
Message-ID: <20070827160247.GD25589@sgi.com> (raw)
In-Reply-To: <20070827155622.GA25589@sgi.com>

This patch adds a lock ordering rule to avoid a potential deadlock when
multiple mmap_sems need to be locked.

Signed-off-by: Dean Nelson <dcn@sgi.com>

Index: linux-2.6/mm/filemap.c
===================================================================
--- linux-2.6.orig/mm/filemap.c	2007-08-09 19:18:15.000000000 -0500
+++ linux-2.6/mm/filemap.c	2007-08-27 09:13:47.435717670 -0500
@@ -78,6 +78,9 @@
  *  ->i_mutex			(generic_file_buffered_write)
  *    ->mmap_sem		(fault_in_pages_readable->do_page_fault)
  *
+ *    When taking multiple mmap_sems, one should lock the lowest-addressed
+ *    one first proceeding on up to the highest-addressed one.
+ *
  *  ->i_mutex
  *    ->i_alloc_sem             (various)
  *

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next prev parent reply	other threads:[~2007-08-27 16:02 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-08-27 15:56 [PATCH 0/4] SGI Altix cross partition memory (XPMEM) Dean Nelson
2007-08-27 15:56 ` Dean Nelson
2007-08-27 15:56 ` Dean Nelson
2007-08-27 15:59 ` [PATCH 1/4] export __put_task_struct for XPMEM Dean Nelson
2007-08-27 15:59   ` Dean Nelson
2007-08-27 15:59   ` Dean Nelson
2007-08-27 16:13   ` Al Viro
2007-08-27 16:13     ` Al Viro
2007-08-27 16:13     ` Al Viro
2007-08-27 18:10     ` Dean Nelson
2007-08-27 18:10       ` Dean Nelson
2007-08-27 18:10       ` Dean Nelson
2007-08-27 18:15       ` Al Viro
2007-08-27 18:15         ` Al Viro
2007-08-27 18:15         ` Al Viro
2007-08-27 19:19         ` Dean Nelson
2007-08-27 19:19           ` Dean Nelson
2007-08-27 19:19           ` Dean Nelson
2007-08-27 19:35           ` Al Viro
2007-08-27 19:35             ` Al Viro
2007-08-27 19:35             ` Al Viro
2007-08-27 20:24             ` Robin Holt
2007-08-27 20:24               ` Robin Holt
2007-08-27 20:24               ` Robin Holt
2007-08-27 20:47               ` Al Viro
2007-08-27 20:47                 ` Al Viro
2007-08-27 20:47                 ` Al Viro
2007-08-28 12:09                 ` Robin Holt
2007-08-28 18:01       ` Christoph Hellwig
2007-08-28 18:01         ` Christoph Hellwig
2007-08-28 18:01         ` Christoph Hellwig
2007-08-27 16:01 ` [PATCH 2/4] export zap_page_range " Dean Nelson
2007-08-27 16:01   ` Dean Nelson
2007-08-27 16:01   ` Dean Nelson
2007-08-27 16:02 ` Dean Nelson [this message]
2007-08-27 16:02   ` [PATCH 3/4] add new lock ordering rule to mm/filemap.c Dean Nelson
2007-08-27 16:02   ` Dean Nelson
2007-08-27 16:41 ` [PATCH 4/4] add SGI Altix cross partition memory (XPMEM) driver Dean Nelson
2007-08-27 16:41   ` Dean Nelson
2007-08-27 20:00   ` Adrian Bunk
2007-08-27 20:00     ` Adrian Bunk
2007-08-27 20:00     ` Adrian Bunk
2007-08-28 18:02   ` Christoph Hellwig
2007-08-28 18:02     ` Christoph Hellwig
2007-08-28 18:02     ` Christoph Hellwig
2007-08-28 19:00     ` Robin Holt
2007-08-28 19:00       ` Robin Holt
2007-08-28 19:00       ` Robin Holt
2007-08-28 19:05       ` Christoph Hellwig
2007-08-28 19:05         ` Christoph Hellwig
2007-08-28 19:05         ` Christoph Hellwig

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