Re: [PATCH 3/3] [PATCH] hugetlb: Enforce quotas during reservation for shared mappings

[Dave Hansen <haveblue@us.ibm.com>]

On Wed, 2007-10-24 at 14:52 -0500, Adam Litke wrote:
> 
> > Since alloc_huge_page() gets the VMA it could, in theory, be doing the
> > accounting.  The other user, hugetlb_cow(), seems to have a similar code
> > path.  But, it doesn't have to worry about shared_page, right?  We can
> > only have COWs on MAP_PRIVATE.
> > 
> > I'm just trying to find ways to future-proof the quotas since they
> > already got screwed up once.  The fewer call sites we have for them, the
> > fewer places they can get screwed up. :)
> 
> Yep.  Originally I wanted to put the hugetlb_get_quota() call inside
> alloc_huge_page() but the devil is in the details.  Failure to get quota
> needs to result in a SIGBUS whereas a standard allocation failure is
> OOM.  Because of this, we'd still need special handling of the
> alloc_huge_page() return value.  While that can be done easily enough, I
> didn't think it was worth it.  

Does it need special handling if we just use ERR_PTR()s?

-- Dave

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