Messages in this thread | | | Date | Fri, 22 Feb 2013 11:33:25 +0800 | From | Alex Shi <> | Subject | Re: [RFC PATCH v3 1/3] sched: schedule balance map foundation |
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On 02/22/2013 10:53 AM, Michael Wang wrote: >> > >>> >> And the final cost is 3000 int and 1030000 pointer, and some padding, >>> >> but won't bigger than 10M, not a big deal for a system with 1000 cpu >>> >> too. >> > >> > Maybe, but quadric stuff should be frowned upon at all times, these >> > things tend to explode when you least expect it. >> > >> > For instance, IIRC the biggest single image system SGI booted had 16k >> > cpus in there, that ends up at something like 14+14+3=31 aka as 2G of >> > storage just for your lookup -- that seems somewhat preposterous. > Honestly, if I'm a admin who own 16k cpus system (I could not even image > how many memory it could have...), I really prefer to exchange 2G memory > to gain some performance. > > I see your point here, the cost of space will grow exponentially, but > the memory of system will also grow, and according to my understanding , > it's faster.
Why not seek other way to change O(n^2) to O(n)?
Access 2G memory is unbelievable performance cost.
There are too many jokes on the short-sight of compute scalability, like Gates' 64K memory in 2000.
-- Thanks Alex
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