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Date: Thu, 23 Jun 2016 01:16:55 +1000
From: Anton Blanchard <anton@samba.org>
To: shreyas@linux.vnet.ibm.com, ego@linux.vnet.ibm.com, mpe@ellerman.id.au,
 mikey@neuling.org, Paul Mackerras <paulus@samba.org>, Benjamin
 Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: cpuidle broken on mainline
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Hi,

I was noticing some pretty big run to run variations on single threaded
benchmarks, and I've isolated it cpuidle issues. If I look at
the cpuidle tracepoint, I notice we only go into the snooze state.

Do we have any known bugs in cpuidle at the moment?

While looking around, I also noticed PM_QOS_CPU_DMA_LATENCY,
which seems like a bad thing for us. It is used in places like
the e1000e adapter:

drivers/net/ethernet/intel/e1000e/netdev.c:
    pm_qos_add_request(&adapter->pm_qos_req, PM_QOS_CPU_DMA_LATENCY

Seems like that would force us into SMT8 mode all the time. Can we
disable it on ppc64le completely?

Anton