* John Stultz <john.stultz@xxxxxxxxxx> wrote:
> In 780427f0e11 (Indicate that clock was set in the pvclock
> gtod notifier), logic was added to pass a CLOCK_WAS_SET
> notification to the pvclock notifier chain.
>
> While that patch added a action flag returned from
> accumulate_nsecs_to_secs(), it only uses the returned value
> in one location, and not in the logarithmic accumulation.
>
> This means if a leap second triggered during the logarithmic
> accumulation (which is most likely where it would happen),
> the notification that the clock was set would not make it to
> the pv notifiers.
>
> This patch extends the logarithmic_accumulation pass down
> that action flag so proper notification will occur.
>
> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
> Cc: Richard Cochran <richardcochran@xxxxxxxxx>
> Cc: <xen-devel@xxxxxxxxxxxxx>
> Cc: stable <stable@xxxxxxxxxxxxxxx> #3.11+
> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
> ---
> kernel/time/timekeeping.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 6bad3d9..998ec751 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -1295,7 +1295,7 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
> * Returns the unconsumed cycles.
> */
> static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
> - u32 shift)
> + u32 shift, unsigned int *action)
I have two complaints about this patch:
1)
I think the 'action' name sucks because it's too obfuscated. It's only
ever set to TK_CLOCK_WAS_SET, so why not name it more descriptively,
i.e. 'clock_was_set'?
2)
Secondly, the proliferation of parameters passed around I think calls
for a helper structure which would carry the (offset, shift,
clock_was_set) triple:
struct acc_params {
cycle_t offset;
u32 shift;
bool clock_was_set;
};
And then passed down like this:
> static cycle_t logarithmic_accumulation(struct timekeeper *tk, struct acc_params *params)
Agreed?
Thanks,
Ingo
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html