Large stack usage in fs code (especially for PPC64)

Nick Piggin nickpiggin at yahoo.com.au
Tue Nov 18 21:07:12 EST 2008


On Tuesday 18 November 2008 09:53, Paul Mackerras wrote:

> I'd love to be able to use a 4k base page size if I could still get
> the reduction in page faults and the expanded TLB reach that we get
> now with 64k pages.  If we could allocate the page cache for large
> files with order-4 allocations wherever possible that would be a good
> start.

That can still have nasty side-effects like fragmentation and 64k
granular reclaim. It also adds complexity to mapping the pages to
userspace.

Christoph's patchset IIRC also only did page cache, wheras I suppose
your kernbench workload is gaining mainly from anonymous page faults.



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