Re: [Qemu-devel] [PATCH, v2] Rewrite mmap_find_vma() to work fine on 64-bit hosts with 32-bit targets

[Kirill A. Shutemov]

On Mon, Nov 10, 2008 at 04:54:35AM +0100, andrzej zaborowski wrote:
> Hi,
> 
> 2008/11/1 Kirill A. Shutemov <address@hidden>:
> > On Sat, Nov 01, 2008 at 04:51:10PM +0000, Jamie Lokier wrote:
> >> Kirill A. Shutemov wrote:
> >> > +        /* Unmap and try again with new page */
> >> > +        munmap(ptr, size);
> >> >          addr += qemu_host_page_size;
> >>
> >> Won't this be rather slow if it has to skip a large mapped area, one
> >> page at a time?
> >
> > If we skip more than one page we increase memory fragmentation.
> 
> This approach makes sense, however the iterating over all pages may
> indeed have performance consequences, plus it would be great if people
> who better know linux-user/ than me commented.  I'll assume that
> everyone is happy with this otherwise.

Paul, can you comment it?

> It may be useful adding a comment on top of the function that it must
> be called with mmap_lock held.

Ok, I'll do it.

-- 
Regards,  Kirill A. Shutemov
 + Belarus, Minsk
 + ALT Linux Team, http://www.altlinux.com/

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