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From: Christoph Lameter <cl@linux.com>
To: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>, Pekka Enberg <penberg@kernel.org>,
	Matt Mackall <mpm@selenic.com>, Mel Gorman <mgorman@suse.de>,
	Yinghai Lu <yinghai@kernel.org>, Tony Luck <tony.luck@intel.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	David Rientjes <rientjes@google.com>,
	Minchan Kim <minchan@kernel.org>,
	Keping Chen <chenkeping@huawei.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 2/4] mm: make consistent use of PG_slab flag
Date: Fri, 6 Jul 2012 08:53:19 -0500 (CDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1207060851310.26441@router.home> (raw)
In-Reply-To: <4FF6A21C.9010509@huawei.com>

On Fri, 6 Jul 2012, Jiang Liu wrote:

> 	This patch is not for hotplug, but is to fix some issues in current
> kernel, such as:
> 	1) make show_mem() on ARM and unicore32 report consistent information
> no matter which slab allocator is used.

The information is only different because allocations do not go through
the slab allocators for SLUB/SLOB.

> 	2) make /proc/kpagecount and /proc/kpageflags return accurate information.

Fix the compound handling in those and the numbers will be correct. This
is also good for other issues that may arise because the flags in the
compound head are not considered.

> 	3) Get rid of risks in mm/memory_failure.c and arch/ia64/kernel/mca_drv.c

Assuming that a slab allocation fits into a page is a dangerous
assumption. There are arches with much large page sizes. Please fix the
code.



WARNING: multiple messages have this Message-ID (diff)
From: Christoph Lameter <cl@linux.com>
To: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>, Pekka Enberg <penberg@kernel.org>,
	Matt Mackall <mpm@selenic.com>, Mel Gorman <mgorman@suse.de>,
	Yinghai Lu <yinghai@kernel.org>, Tony Luck <tony.luck@intel.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	David Rientjes <rientjes@google.com>,
	Minchan Kim <minchan@kernel.org>,
	Keping Chen <chenkeping@huawei.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 2/4] mm: make consistent use of PG_slab flag
Date: Fri, 6 Jul 2012 08:53:19 -0500 (CDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1207060851310.26441@router.home> (raw)
In-Reply-To: <4FF6A21C.9010509@huawei.com>

On Fri, 6 Jul 2012, Jiang Liu wrote:

> 	This patch is not for hotplug, but is to fix some issues in current
> kernel, such as:
> 	1) make show_mem() on ARM and unicore32 report consistent information
> no matter which slab allocator is used.

The information is only different because allocations do not go through
the slab allocators for SLUB/SLOB.

> 	2) make /proc/kpagecount and /proc/kpageflags return accurate information.

Fix the compound handling in those and the numbers will be correct. This
is also good for other issues that may arise because the flags in the
compound head are not considered.

> 	3) Get rid of risks in mm/memory_failure.c and arch/ia64/kernel/mca_drv.c

Assuming that a slab allocation fits into a page is a dangerous
assumption. There are arches with much large page sizes. Please fix the
code.


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  reply	other threads:[~2012-07-06 13:53 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-03  3:57 [RFC PATCH 1/4] mm: introduce a safer interface to check whether a page is managed by SLxB Jiang Liu
2012-07-03  3:57 ` Jiang Liu
2012-07-03  3:57 ` [RFC PATCH 2/4] mm: make consistent use of PG_slab flag Jiang Liu
2012-07-03  3:57   ` Jiang Liu
2012-07-05 14:47   ` Christoph Lameter
2012-07-05 14:47     ` Christoph Lameter
2012-07-05 16:15     ` Jiang Liu
2012-07-05 16:15       ` Jiang Liu
2012-07-05 17:37       ` Christoph Lameter
2012-07-05 17:37         ` Christoph Lameter
2012-07-06  8:30         ` Jiang Liu
2012-07-06  8:30           ` Jiang Liu
2012-07-06 13:53           ` Christoph Lameter [this message]
2012-07-06 13:53             ` Christoph Lameter
2012-07-03  3:57 ` [RFC PATCH 3/4] SLAB: minor code cleanup Jiang Liu
2012-07-03  3:57   ` Jiang Liu
2012-07-03 10:02   ` Cong Wang
2012-07-03  3:57 ` [RFC PATCH 4/4] mm: change slob's struct page definition to accomodate struct page changes Jiang Liu
2012-07-03  3:57   ` Jiang Liu
2012-07-03 10:22   ` Cong Wang
2012-07-03  9:56 ` [RFC PATCH 1/4] mm: introduce a safer interface to check whether a page is managed by SLxB Cong Wang
2012-07-05 14:45 ` Christoph Lameter
2012-07-05 14:45   ` Christoph Lameter
2012-07-05 15:55   ` Jiang Liu
2012-07-05 15:55     ` Jiang Liu
2012-07-05 17:36     ` Christoph Lameter
2012-07-05 17:36       ` Christoph Lameter
2012-07-06  7:29       ` Jiang Liu
2012-07-06  7:29         ` Jiang Liu
2012-07-06 13:50         ` Christoph Lameter
2012-07-06 13:50           ` Christoph Lameter
2012-07-06 15:36           ` Jiang Liu
2012-07-06 15:36             ` Jiang Liu
2012-09-04  9:18 ` Wen Congyang
2012-09-04  9:18   ` Wen Congyang
2012-09-04 12:13   ` Jiang Liu
2012-09-04 12:13     ` Jiang Liu

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