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From: Andrew Morton <akpm@osdl.org>
To: Zhonglin Zhang <zhonglinzh@mobilesoft.com.cn>
Cc: linux-kernel@vger.kernel.org
Subject: Re: a little improvement  for vmalloc
Date: Wed, 5 Jan 2005 19:38:27 -0800	[thread overview]
Message-ID: <20050105193827.12d83341.akpm@osdl.org> (raw)
In-Reply-To: <1104981532.628.10.camel@milo>

Zhonglin Zhang <zhonglinzh@mobilesoft.com.cn> wrote:
>
> In FUNCTION __vmalloc ,
> 
>  There is a statement;
> 
>  if (!size || (size >> PAGE_SHIFT) > num_physpages)
>          return NULL;

Probably the second part of the test should be removed.  If the requested
area size is

a) less than the size of the vmalloc arena and

b) more than the number of allocatable pages

then yes, the machine will have a ton of trouble allocating the memory and
will actually lock up.

But the only way that will happen is if some code is made to do a large
number of smaller vmallocs.  Nobody does a huge single vmalloc like that.


  reply	other threads:[~2005-01-06  3:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-01-06  3:18 a little improvement for vmalloc Zhonglin Zhang
2005-01-06  3:38 ` Andrew Morton [this message]
2005-01-06  9:26   ` Anton Altaparmakov

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