[RFT][patch] Scheduling for HTT and not only

[Alexander Motin]

On 02/16/12 10:48, Alexander Motin wrote:
> On 02/15/12 21:54, Jeff Roberson wrote:
>> On Wed, 15 Feb 2012, Alexander Motin wrote:
>>> As before I've tested this on Core i7-870 with 4 physical and 8
>>> logical cores and Atom D525 with 2 physical and 4 logical cores. On
>>> Core i7 I've got speedup up to 10-15% in super-smack MySQL and
>>> PostgreSQL indexed select for 2-8 threads and no penalty in other
>>> cases. pbzip2 shows up to 13% performance increase for 2-5 threads and
>>> no penalty in other cases.
>>
>> Can you also test buildworld or buildkernel with a -j value twice the
>> number of cores? This is an interesting case because it gets little
>> benefit from from affinity and really wants the best balancing possible.
>> It's also the first thing people will complain about if it slows.
>
> All night long buildworld run on Core i7-2600K (4/8 cores) with 8GB RAM
> and RAID0 of two fast SSDs found no bad surprises:
>
> old new %
> 1 4242.33 4239.69 -0.0622299538
> 2 2376.4433 2340.47 -1.5137453521
> 4 1581.3033 1430.1733 -9.5573063055
> 6 1394.8033 1348.0533 -3.3517270858
> 8 1365.8067 1315.87 -3.6562055231
> 10 1312.8533
> 12 1350.23 1313.2667 -2.7375558238
> 16 1346.2267 1306.0733 -2.9826625783
> 20 1313.31
>
> Each point there averaged of 3 runs.

Ah! Just recalled, this kernel included patch from avg@ that removed 
extra equal topology level from the tree. That could improve balancer 
behavior in this case of single-socket system.

-- 
Alexander Motin