Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 8 Apr 2015 14:19:23 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 1/5] perf: Add a flags parameter to pmu txn interfaces |
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On Tue, Apr 07, 2015 at 05:34:55PM -0700, Sukadev Bhattiprolu wrote: > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > index 2b62198..4dc3d70 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -240,20 +240,27 @@ struct pmu { > * > * Start the transaction, after this ->add() doesn't need to > * do schedulability tests. > + * > + * Optional. > */ > - void (*start_txn) (struct pmu *pmu); /* optional */ > +#define PERF_PMU_TXN_ADD 0x1 /* txn to add/schedule event on PMU */
Please do not interleave these flags in the structure. Maybe place it near PERF_EVENT_TXN.
> + void (*start_txn) (struct pmu *pmu, int flags); > /* > * If ->start_txn() disabled the ->add() schedulability test > * then ->commit_txn() is required to perform one. On success > * the transaction is closed. On error the transaction is kept > * open until ->cancel_txn() is called. > + * > + * Optional. > */ > - int (*commit_txn) (struct pmu *pmu); /* optional */ > + int (*commit_txn) (struct pmu *pmu, int flags); > /* > * Will cancel the transaction, assumes ->del() is called > * for each successful ->add() during the transaction. > + * > + * Optional. > */ > - void (*cancel_txn) (struct pmu *pmu); /* optional */ > + void (*cancel_txn) (struct pmu *pmu, int flags); > > /* > * Will return the value for perf_event_mmap_page::index for this event,
So (again), why also pass the flags to cancel/commit ?
The transaction state _has_ to already record it, otherwise it doesn't know if add/read are part of one.
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