Messages in this thread | | | Date | Wed, 10 Jul 2019 14:57:44 -0400 | From | Steven Rostedt <> | Subject | Re: sched_clock and device suspend/resume |
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On Wed, 10 Jul 2019 20:35:32 +0200 (CEST) Thomas Gleixner <tglx@linutronix.de> wrote:
> On Wed, 10 Jul 2019, Steven Rostedt wrote: > > > > > [ Resending as your Cc was screwed up and caused my reply to mess up > > the Cc list ] > > > > On Wed, 10 Jul 2019 08:20:37 -0700 > > Sodagudi Prasad <psodagud@codeaurora.org> wrote: > > > > > Another option is printing the epoch/cycles information in every print > > > statement similar to thread id or processor id added > > > recently(CONFIG_PRINTK_CALLER). This can be avoided if we start > > > accounting suspend time in sched_clock. > > > > Or another option is add a new clock that printk and tracing can use. > > tracing already can switch between clocks trivially. > > > > sched_clock_continuous() ? (I know, horrible name), that simply keeps > > track of the time delta at suspend and returns: > > > > sched_clock() + delta; > > Which you get already when you do > > # echo boot > /sys/kernel/debug/tracing/trace_clock >
So basically the answer here is to change printk to use ktime_get_boot_fast_ns() instead of local_clock()?
-- Steve
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