Re: [PATCH 1/2] Report the pagesize backing a VMA in /proc/pid/smaps

From: Mel Gorman
Date: Tue Sep 23 2008 - 15:47:16 EST


On (23/09/08 21:15), KOSAKI Motohiro didst pronounce:
> > > The corollary is that someone running with a 64K base page kernel may be
> > > surprised that the pagesize is always 4K. However I'll check if there is
> > > a simple way of checking out if the MMU size differs from PAGE_SIZE.
> >
> > Sure. If it isn't easy, the best thing to do is probably just to
> > document the "interesting" behavior.
>
> Dave, please let me know getpagesize() function return to 4k or 64k on ppc64.
> I think the PageSize line of the /proc/pid/smap and getpagesize() result should be matched.
>
> otherwise, enduser may be confused.
>

To distinguish between the two, I now report the kernel pagesize and the
mmu pagesize like so

KernelPageSize: 64 kB
MMUPageSize: 4 kB

This is running a kernel with a 64K base pagesize on a PPC970MP which
does not support 64K hardware pagesizes.

Does this make sense?

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
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