Re: [PATCH][RFC v7] timekeeping: Ignore the bogus sleep time if pm_trace is enabled

From: John Stultz
Date: Thu Nov 10 2016 - 13:26:15 EST


On Wed, Nov 9, 2016 at 8:55 PM, Chen Yu <yu.c.chen@xxxxxxxxx> wrote:
> Previously we encountered some memory overflow issues due to
> the bogus sleep time brought by inconsistent rtc, which is
> triggered when pm_trace is enabled, and we have fixed it
> in recent kernel. However it's improper in the first place
> to call __timekeeping_inject_sleeptime() in case that pm_trace
> is enabled simply because that "hash" time value will wreckage
> the timekeeping subsystem.
>
> This patch is originally written by Thomas, which would bypass
> the bogus rtc interval when pm_trace is enabled.
> Meanwhile, if system succeed to resume back with pm_trace set, the
> users are warned to adjust the bogus rtc either by ntp-date or rdate,
> by resetting pm_trace_rtc_abused to false, otherwise above tools might
> not work as expected.
>
> Originally-from: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Xunlei Pang <xlpang@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>


Looks ok to me. I'm queueing it up for testing. If no one objects
(and I don't see any issues) I'll merge it to my tree and push it to
-tip through Thomas.

thanks
-john