Re: [patch] CFS scheduler, -v12

From: Chris Friesen
Date: Tue May 22 2007 - 12:49:19 EST


Ingo Molnar wrote:

CFS is fair even on SMP. Consider for example the worst-case 3-tasks-on-2-CPUs workload on a 2-CPU box:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2658 mingo 20 0 1580 248 200 R 67 0.0 0:56.30 loop
2656 mingo 20 0 1580 252 200 R 66 0.0 0:55.55 loop
2657 mingo 20 0 1576 248 200 R 66 0.0 0:55.24 loop

66% of CPU time for each task. The 'TIME+' column shows a 2% spread between the slowest and the fastest loop after just 1 minute of runtime (and the spread gets narrower with time).

Is there a way in CFS to tune the amount of time over which the load balancer is fair? (Of course there would be some overhead involved.)

Chris
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