[RFC PATCH v2 0/4] CPUs capacity information for heterogeneous systems

On 19/01/16 11:23, Juri Lelli wrote:

Hi Catalin,

On 19/01/16 10:59, Catalin Marinas wrote:

quoted

On Mon, Jan 18, 2016 at 05:42:58PM +0100, Vincent Guittot wrote:

quoted

On 18 January 2016 at 17:30, Juri Lelli [off-list ref] wrote:

quoted

On 18/01/16 17:13, Vincent Guittot wrote:

quoted

On 18 January 2016 at 16:13, Juri Lelli [off-list ref] wrote:

quoted

On 15/01/16 11:50, Steve Muckle wrote:

quoted

On 01/08/2016 06:09 AM, Juri Lelli wrote:

[...]

quoted

Two questions:

1. How is the boot time affected by the benchmark?
2. How is the boot time affected by considering all the CPUs the same?

My preference is for DT and sysfs (especially useful for
development/tuning) but I'm not opposed to a boot-time benchmark if
people insist on it. If the answer to point 2 is "insignificant", we
could as well defer the capacity setting to user space (sysfs).

Given that we are not targeting boot time with this, but rather better
performance afterwards, I don't expect significant differences; but,
I'll get numbers :).

I've got some boot time numbers on TC2 and Juno based on timestamps.
They are of course not accurate and maybe not so representative of
products, but I guess still ballpark right.

I'm generally seeing ~1sec increase in boot time for 1 and practically
no difference for 2 (even after having added patches that provide
runtime performance improvements).

Best,

- Juri