Re: [PATCH] Fix NUMA node sizing in nr_free_zone_pages

From: Martin J. Bligh
Date: Sat Jul 30 2005 - 08:53:37 EST

>> We are iterating over all nodes in nr_free_zone_pages(). Because the
>> fallback zonelists contain all nodes in the system, and we walk all
>> the zonelists, we're counting memory multiple times (once for each
>> node). This caused us to make a size estimate of 32GB for an 8GB
>> AMD64 box, which makes all the dirty ratio calculations, etc incorrect.
>> There's still a further bug to fix from e820 holes causing overestimation
>> as well, but this fix is separate, and good as is, and fixes one class
>> of problems. Problem found by Badari, and tested by Ram Pai - thanks!
> Alas my non-NUMA EMT64 box still gets it wrong.
> nr_free_pagecache_pages() is still returning 1572864 on a 4G box.

Yeah, it will do - is the e820 bug I mentioned above. Patch is half-written,
will finish it off ASAP, but I'll be out today ;-(


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