Re: hugepage patches

[ebiederm@xmission.com (Eric W. Biederman)]

Andrew Morton <akpm@digeo.com> writes:

> ebiederm@xmission.com (Eric W. Biederman) wrote:
> >
> > I can't imagine it being useful to guys like oracle without MAP_SHARED
> > support....
> 
> MAP_SHARED is supported.  I haven't tested it much though.

Given that none of the standard kernel idioms to prevent races in
this kind of code are present, I would be very surprised if it
was not racy.

- inode->i_sem is not taken to protect inode->i_size.
- After successfully allocating a page, a test is not made to see if
  another process with the same mapping has allocated the page first.

Eric
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