Re: [PATCH] memblock, numa: Binary search node id

From: Yinghai Lu
Date: Fri Aug 16 2013 - 20:51:11 EST


On Fri, Aug 16, 2013 at 12:01 PM, Russ Anderson <rja@xxxxxxx> wrote:
> On Thu, Aug 15, 2013 at 01:43:48PM -0700, Andrew Morton wrote:
>> On Wed, 14 Aug 2013 22:46:29 -0700 Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>>
>> > Current early_pfn_to_nid() on arch that support memblock go
>> > over memblock.memory one by one, so will take too many try
>> > near the end.
>> >
>> > We can use existing memblock_search to find the node id for
>> > given pfn, that could save some time on bigger system that
>> > have many entries memblock.memory array.
>>
>> Looks nice. I wonder how much difference it makes.
>
> Here are the timing differences for several machines.
> In each case with the patch less time was spent in __early_pfn_to_nid().
>
>
> 3.11-rc5 with patch difference (%)
> -------- ---------- --------------
> UV1: 256 nodes 9TB: 411.66 402.47 -9.19 (2.23%)
> UV2: 255 nodes 16TB: 1141.02 1138.12 -2.90 (0.25%)
> UV2: 64 nodes 2TB: 128.15 126.53 -1.62 (1.26%)
> UV2: 32 nodes 2TB: 121.87 121.07 -0.80 (0.66%)
> Time in seconds.
>

Thanks.

9T one have more entries in memblock.memory?

Yinghai
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