Messages in this thread | | | Date | Tue, 19 Mar 2019 22:00:18 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 4/8] perf/x86: Remove PERF_X86_EVENT_COMMITTED |
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On Tue, Mar 19, 2019 at 01:48:18PM -0700, Stephane Eranian wrote: > On Thu, Mar 14, 2019 at 6:11 AM Peter Zijlstra <peterz@infradead.org> wrote: > > > For x86_pmu_commit_txn(), cpuc->n_events is updated, but we can > > trivially compute the desired value with cpuc->n_txn -- the number of > > events added in this transaction. > > > I suggest you put this explanation in the code so that it is easier to > understand.
Right, I actually attempted writing that comment a few times but every time it became a mess. I'll try again, because you're quite right, this is a bit magical.
> > - for (i = 0; i < n; i++) { > > + i = cpuc->n_events; > > + if (cpuc->txn_flags & PERF_PMU_TXN_ADD) > > + i -= cpuc->n_txn; > > + > > + for (; i < n; i++) {
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