Messages in this thread | | | Date | Mon, 28 Feb 2005 20:41:31 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH] A new entry for /proc |
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On Mon, 28 Feb 2005, Mauricio Lin wrote: > > Now I am testing with /proc/pid/smaps and the values are showing that > the old one is faster than the new one. So I will keep using the old > smaps version.
Sorry, I don't have time for more than the briefest look.
It appears that your old resident_mem_size method is just checking pte_present, whereas your new smaps_pte_range method is also doing pte_page (yet no prior check for pfn_valid: wrong) and checking !PageReserved i.e. accessing the struct page corresponding to each pte. So it's not a fair comparison, your new method is accessing many more cachelines than your old method.
Though it's correct to check pfn_valid and !PageReserved to get the same total rss as would be reported elsewhere, I'd suggest that it's really not worth the overhead of those struct page accesses: just stick with the pte_present test.
Your smaps_pte_range is missing pte_unmap?
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