Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
I see the same on a PandaBoard and PandaBoard ES. In both cases the CPU is locked to 1 GHz and other power management features are disabled.
-- Michael
On 17 August 2012 00:37, Michael Hope michael.hope@linaro.org wrote:
Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
Hacked how? How big a change? What does perf say?
On 17 August 2012 00:37, Michael Hope michael.hope@linaro.org wrote:
Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
Hacked how? How big a change? What does perf say?
It's a different config but otherwise the same as the Ubuntu linux-ti-omap4_3.2.0-1412.16 package. perf is next.
-- Michael
On 19 August 2012 23:55, Michael Hope michael.hope@linaro.org wrote:
On 17 August 2012 00:37, Michael Hope michael.hope@linaro.org wrote:
Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
Hacked how? How big a change? What does perf say?
It's a different config but otherwise the same as the Ubuntu linux-ti-omap4_3.2.0-1412.16 package. perf is next.
So... what did you change?
On 20 August 2012 11:36, Mans Rullgard mans.rullgard@linaro.org wrote:
On 19 August 2012 23:55, Michael Hope michael.hope@linaro.org wrote:
On 17 August 2012 00:37, Michael Hope michael.hope@linaro.org wrote:
Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
Hacked how? How big a change? What does perf say?
It's a different config but otherwise the same as the Ubuntu linux-ti-omap4_3.2.0-1412.16 package. perf is next.
So... what did you change?
The config file is here: http://people.linaro.org/~michaelh/incoming/precise.config
It's mainly turning power management and similar features off. I didn't touch the errata or other core config. The next step would be to run the Ubuntu supplied build and see if performs the same as my reconfigured version to check if it's in the Precise tree or just my fault.
-- Michael
On 20 August 2012 00:41, Michael Hope michael.hope@linaro.org wrote:
On 20 August 2012 11:36, Mans Rullgard mans.rullgard@linaro.org wrote:
On 19 August 2012 23:55, Michael Hope michael.hope@linaro.org wrote:
On 17 August 2012 00:37, Michael Hope michael.hope@linaro.org wrote:
Hi there. I'm seeing a huge improvement in the SPEC floating point benchmarks between a hacked Ubuntu Precise 3.2.14 kernel and Linus 3.5. Does anyone know why off the top of their head?
Hacked how? How big a change? What does perf say?
It's a different config but otherwise the same as the Ubuntu linux-ti-omap4_3.2.0-1412.16 package. perf is next.
So... what did you change?
The config file is here: http://people.linaro.org/~michaelh/incoming/precise.config
It's mainly turning power management and similar features off. I didn't touch the errata or other core config. The next step would be to run the Ubuntu supplied build and see if performs the same as my reconfigured version to check if it's in the Precise tree or just my fault.
Changing power management options can affect the maximum CPU clock, but that would not be specific to floating-point.
Let's get those perf numbers and see what that hints at.
-
Mans Rullgard -
Michael Hope