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

Sergei Shtylyov sshtylyov at mvista.com
Wed Jun 6 20:53:08 EST 2012


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 at intel.com>

WBR, Sergei

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