On Wed, 2015-05-13 at 16:32 +0100, Arnd Bergmann wrote:
On Wednesday 13 May 2015 16:21:24 Pawel Moll wrote:
diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index df5f307..7d9879e 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -921,9 +921,8 @@ static void arm_ccn_pmu_event_start(struct perf_event *event, int flags) * attribute). */ if (!ccn->irq)
__hrtimer_start_range_ns(&ccn->dt.hrtimer,arm_ccn_pmu_timer_period(), 0,HRTIMER_MODE_REL_PINNED, 0);
hrtimer_start(&ccn->dt.hrtimer, arm_ccn_pmu_timer_period(),HRTIMER_MODE_REL_PINNED);/* Set the DT bus input, engaging the counter */ arm_ccn_pmu_xp_dt_config(event, 1);
Is this correct by itself, or do we need to pull in the branch that contains c6eb3f70d44828 ("hrtimer: Get rid of hrtimer softirq") from Thomas? The other similar patches that Thomas did contain a comment about the conversion being safe after hrtimer_start() no longer uses a softirq, but it is still in use in 4.1-rc3.
That's why I asked who should carry this patch ;-)
Now, the answer to your question is: the result will not be worse than the what was there before you pulled my updates, as the code was using normal hrtimer_start(). It's just when I realised that it should be pinned I looked at what x86 uncore pmu is doing and shamelessly (and probably a bit mindlessly) copied the "do not wakeup" version from there.
Pawel