Messages in this thread Patch in this message | | | From | mita akinobu <> | Subject | Re: [PATCH] shows Active/Inactive on per-node meminfo | Date | Sat, 21 Aug 2004 15:29:37 +0900 |
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On Saturday 21 August 2004 03:48, Jesse Barnes wrote: > Just FYI, loops like this are going to be very slow on a large machine. > Iterating over every node in the system involves a TLB miss on every > iteration along with an offnode reference and possibly cacheline demotion.
get_zone_counts() is used by max_sane_readahead(), and max_sane_readahead() is often called in filemap_nopage().
If iterating over every node is going to be very slow, the following change would have a little bit of improvement on a large machine?
--- linux-2.6.8.1-mm3/mm/readahead.c.orig 2004-08-21 15:18:08.924273720 +0900 +++ linux-2.6.8.1-mm3/mm/readahead.c 2004-08-21 15:22:31.123413392 +0900 @@ -572,6 +572,6 @@ unsigned long max_sane_readahead(unsigne unsigned long inactive; unsigned long free; - get_zone_counts(&active, &inactive, &free); + __get_zone_counts(&active, &inactive, &free, NODE_DATA(numa_node_id())); return min(nr, (inactive + free) / 2); }
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