Re: [PATCH v6 1/4] sched/clock: interface to allow timestamps early in boot

Russell King - ARM Linux
2017-09-27T14:45:34Z

On Wed, Aug 30, 2017 at 02:03:22PM -0400, Pavel Tatashin wrote:
> In Linux printk() can output timestamps next to every line. This is very
> useful for tracking regressions, and finding places that can be optimized.
> However, the timestamps are available only later in boot. On smaller
> machines it is insignificant amount of time, but on larger it can be many
> seconds or even minutes into the boot process.

The sched_clock work I did for ARM could be setup really early at boot,
from setup_arch(). I tried to encourage platforms to do that, but all
my encouragement fell on deaf ears - most people setup the sched_clock
source along side the time initialisation on ARM.

I don't think we need yet another "early" mechanism to solve this problem,
we just need people to use the existing mechanism to register their
sched_clock implementation earlier.

--
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