Re: [RFC][PATCH 09/11] perf: Default PMU ops

Frederic Weisbecker
2010-06-29T14:49:17Z

On Thu, Jun 24, 2010 at 04:28:13PM +0200, Peter Zijlstra wrote:
> Provide default implementations for the pmu txn methods, this allows
> us to remove some conditional code.
>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> ---
> kernel/perf_event.c | 48 ++++++++++++++++++++++++++++++++++++------------
> 1 file changed, 36 insertions(+), 12 deletions(-)
>
> Index: linux-2.6/kernel/perf_event.c
> ===================================================================
> --- linux-2.6.orig/kernel/perf_event.c
> +++ linux-2.6/kernel/perf_event.c
> @@ -656,21 +656,14 @@ group_sched_in(struct perf_event *group_
> {
> struct perf_event *event, *partial_group = NULL;
> struct pmu *pmu = group_event->pmu;
> - bool txn = false;
>
> if (group_event->state == PERF_EVENT_STATE_OFF)
> return 0;
>
> - /* Check if group transaction availabe */
> - if (pmu->start_txn)
> - txn = true;
> -
> - if (txn)
> - pmu->start_txn(pmu);
> + pmu->start_txn(pmu);
>
> if (event_sched_in(group_event, cpuctx, ctx)) {
> - if (txn)
> - pmu->cancel_txn(pmu);
> + pmu->cancel_txn(pmu);
> return -EAGAIN;
> }
>
> @@ -684,7 +677,7 @@ group_sched_in(struct perf_event *group_
> }
> }
>
> - if (!txn || !pmu->commit_txn(pmu))
> + if (!pmu->commit_txn(pmu))
> return 0;
>
> group_error:
> @@ -699,8 +692,7 @@ group_error:
> }
> event_sched_out(group_event, cpuctx, ctx);
>
> - if (txn)
> - pmu->cancel_txn(pmu);
> + pmu->cancel_txn(pmu);
>
> return -EAGAIN;
> }
> @@ -4755,6 +4747,26 @@ static struct list_head pmus;
> static DEFINE_MUTEX(pmus_lock);
> static struct srcu_struct pmus_srcu;
>
> +static void perf_pmu_nop(struct pmu *pmu)
> +{
> +}
> +
> +static void perf_pmu_start_txn(struct pmu *pmu)
> +{
> + perf_pmu_disable(pmu);
> +}
> +
> +static int perf_pmu_commit_txn(struct pmu *pmu)
> +{
> + perf_pmu_enable(pmu);
> + return 0;
> +}
> +
> +static void perf_pmu_cancel_txn(struct pmu *pmu)
> +{
> + perf_pmu_enable(pmu);

Did you mean disable here?