Re: [RFC PATCH] sched/numa: do load balance between remote nodes

From: Sergei Shtylyov
Date: Wed Jun 06 2012 - 06:53:49 EST


Hello.

On 06-06-2012 10:52, Alex Shi wrote:

commit cb83b629b

Please also specify that commit's summary in parens.

remove the NODE sched domain and check if the node
distance in SLIT table is farther than REMOTE_DISTANCE, if so, it will
lose the load balance chance at exec/fork/wake_affine points.

But actually, even the node distance is farther than REMOTE_DISTANCE,
Modern CPUs also has QPI like connections, that make memory access is

"Is" not needed here.

not too slow between nodes. So above losing on NUMA machine make a
huge performance regression on benchmark: hackbench, tbench, netperf
and oltp etc.

This patch will recover the scheduler behavior to old mode on all my
Intel platforms: NHM EP/EX, WSM EP, SNB EP/EP4S, and so remove the
perfromance regressions. (all of them just has 2 kinds distance, 10 21)

Signed-off-by: Alex Shi<alex.shi@xxxxxxxxx>

WBR, Sergei
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