Messages in this thread | | | Subject | Re: a little improvement for vmalloc | From | Anton Altaparmakov <> | Date | Thu, 06 Jan 2005 09:26:41 +0000 |
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On Wed, 2005-01-05 at 19:38 -0800, Andrew Morton wrote: > 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.
I thought that second test was to avoid stupid bugs that may exist in some random (perhaps ex-tree) modules that would otherwise cause the machine to lockup...
Best regards,
Anton -- Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/
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