From: Gary Hade <garyhade@us.ibm.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Gary Hade <garyhade@us.ibm.com>,
Badari Pulavarty <pbadari@us.ibm.com>,
Alex Chiang <achiang@hp.com>,
linux-kernel@vger.kernel.org
Subject: Re: [patch -mm] mm: slab allocate memory section nodemask for large systems
Date: Wed, 18 Nov 2009 10:35:24 -0800 [thread overview]
Message-ID: <20091118183523.GA7793@us.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.00.0911171618430.25821@chino.kir.corp.google.com>
Hi David,
On Tue, Nov 17, 2009 at 04:19:30PM -0800, David Rientjes wrote:
> Nodemasks should not be allocated on the stack for large systems (when it
> is larger than 256 bytes) since there is a threat of overflow.
>
> This patch causes the unregister_mem_sect_under_nodes() nodemask to be
> allocated on the stack for smaller systems and be allocated by slab for
> larger systems.
I notice that there are many other functions that always allocate
nodemask_t objects on the stack. In addition to several that add
a single instance to the stack, cpuset_attach() in kernel/cpuset.c
adds 2 instances and all that are created by using SYSCALL_DEFINE4()
in mm/mempolicy.c add 3 instances. Are there plans to correct the
other functions as well or is there something about
unregister_mem_sect_under_nodes() that makes it more likely to
cause stack overflows than the others?
Gary
--
Gary Hade
System x Enablement
IBM Linux Technology Center
503-578-4503 IBM T/L: 775-4503
garyhade@us.ibm.com
http://www.ibm.com/linux/ltc
next prev parent reply other threads:[~2009-11-18 18:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-18 0:19 [patch -mm] mm: slab allocate memory section nodemask for large systems David Rientjes
2009-11-18 18:35 ` Gary Hade [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-10-22 4:15 [PATCH v2 0/5] mm: modest useability enhancements for node sysfs attrs Alex Chiang
2009-10-22 4:15 ` [PATCH v2 1/5] mm: add numa node symlink for memory section in sysfs Alex Chiang
2009-10-22 19:51 ` David Rientjes
2009-10-27 19:59 ` Alex Chiang
2009-10-27 21:27 ` David Rientjes
2009-10-28 8:31 ` Heiko Carstens
2009-10-28 9:03 ` David Rientjes
2009-10-28 18:39 ` Alex Chiang
2009-10-28 20:43 ` [patch -mm] mm: slab allocate memory section nodemask for large systems David Rientjes
2009-11-02 20:47 ` Alex Chiang
2009-11-04 2:00 ` David Rientjes
2009-11-10 20:51 ` Andrew Morton
2009-11-10 20:55 ` David Rientjes
2009-11-10 21:26 ` Alex Chiang
2009-11-10 21:38 ` Andrew Morton
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