Messages in this thread | | | Date | Wed, 1 Dec 2004 17:59:24 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH]: 1/4 batch mark_page_accessed() |
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Marcelo Tosatti <marcelo.tosatti@cyclades.com> wrote: > > > I don't think that atomic_inc will be particularly > > costly. generic_file_{write,read}() call find_get_page() just before > > calling mark_page_accessed(), so cache-line with page reference counter > > is most likely still exclusive owned by this CPU. > > Assuming that is true - what could cause the slowdown?
It isn't true. Atomic ops have a considerable overhead, and this is unrelated to cache misses. This is especially true of p4's.
Now, that overhead may be justified. Needs more study. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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