Re: page fault scalability patch V11 [0/7]: overview

William Lee Irwin III
2004-11-20T02:04:01Z

On Fri, Nov 19, 2004 at 11:42:39AM -0800, Christoph Lameter wrote:
> A. make_rss_atomic. The earlier releases contained that patch but
> then another variable (such as anon_rss) was introduced that would
> have required additional atomic operations. Atomic rss operations
> are also causing slowdowns on machines with a high number of cpus
> due to memory contention.
> B. remove_rss. Replace rss with a periodic scan over the vm to
> determine rss and additional numbers. This was also discussed on
> linux-mm and linux-ia64. The scans while displaying /proc data
> were undesirable.

Split counters easily resolve the issues with both these approaches
(and apparently your co-workers are suggesting it too, and have
performance results backing it).

-- wli