Re: [PATCH] fs: use kmalloc() to allocate fdmem if possible

[Avi Kivity]

On 05/03/2010 12:22 PM, Jiri Slaby wrote:
> On 05/03/2010 11:18 AM, Avi Kivity wrote:
>    
> > On 05/03/2010 12:03 PM, Jiri Slaby wrote:
> >      
> > > > > Because vmalloc is used to allocate virtually contiguous memory. v in
> > > > > vmalloc means virtually.
> > > > >
> > > > >
> > > > >
> > > > >            
> > > > A kmalloc()ed page is virtually contiguous, satisfying your requirement.
> > > >
> > > >          
> > > But it won't work well for vmalloc_to_{page,pfn} and similar.
> > >        
> > Modify vmalloc_to_{page,pfn} accordingly.
> >      
> When you get a slub in the middle of page, how?
>    

Er, right.  So a separate API is needed for users who are interested in 
memory, not pages.

> > > Some code
> > > may expect vmalloc result to be in the vmalloc area and page-aligned
> > > (both in position and size).
> > >
> > >        
> > Both would be a bug IMO.  vmalloc() follows kmalloc() and malloc() which
> > only guarantee natural alignment.
> >      
> Nope, from what I understand, vmalloc aligns (uses page allocator). Even
> for purposes of vmalloc_to_*.
>    

Correct, my mistake.

--
error compiling committee.c: too many arguments to function

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