On Thu, Jan 10, 2013 at 8:50 PM, Jacob Shin <[email protected]> wrote: > From: Robert Richter <[email protected]> > > Code simplification. No functional changes. > > Signed-off-by: Robert Richter <[email protected]> > Signed-off-by: Jacob Shin <[email protected]>
Acked-by: Stephane Eranian <[email protected]> > --- > arch/x86/kernel/cpu/perf_event_amd.c | 68 > +++++++++++++--------------------- > 1 file changed, 26 insertions(+), 42 deletions(-) > > diff --git a/arch/x86/kernel/cpu/perf_event_amd.c > b/arch/x86/kernel/cpu/perf_event_amd.c > index c93bc4e..e7963c7 100644 > --- a/arch/x86/kernel/cpu/perf_event_amd.c > +++ b/arch/x86/kernel/cpu/perf_event_amd.c > @@ -256,9 +256,8 @@ amd_get_event_constraints(struct cpu_hw_events *cpuc, > struct perf_event *event) > { > struct hw_perf_event *hwc = &event->hw; > struct amd_nb *nb = cpuc->amd_nb; > - struct perf_event *old = NULL; > - int max = x86_pmu.num_counters; > - int i, j, k = -1; > + struct perf_event *old; > + int idx, new = -1; > > /* > * if not NB event or no NB, then no constraints > @@ -276,48 +275,33 @@ amd_get_event_constraints(struct cpu_hw_events *cpuc, > struct perf_event *event) > * because of successive calls to x86_schedule_events() from > * hw_perf_group_sched_in() without hw_perf_enable() > */ > - for (i = 0; i < max; i++) { > - /* > - * keep track of first free slot > - */ > - if (k == -1 && !nb->owners[i]) > - k = i; > + for (idx = 0; idx < x86_pmu.num_counters; idx++) { > + if (new == -1 || hwc->idx == idx) > + /* assign free slot, prefer hwc->idx */ > + old = cmpxchg(nb->owners + idx, NULL, event); > + else if (nb->owners[idx] == event) > + /* event already present */ > + old = event; > + else > + continue; > + > + if (old && old != event) > + continue; > + > + /* reassign to this slot */ > + if (new != -1) > + cmpxchg(nb->owners + new, event, NULL); > + new = idx; > > /* already present, reuse */ > - if (nb->owners[i] == event) > - goto done; > - } > - /* > - * not present, so grab a new slot > - * starting either at: > - */ > - if (hwc->idx != -1) { > - /* previous assignment */ > - i = hwc->idx; > - } else if (k != -1) { > - /* start from free slot found */ > - i = k; > - } else { > - /* > - * event not found, no slot found in > - * first pass, try again from the > - * beginning > - */ > - i = 0; > - } > - j = i; > - do { > - old = cmpxchg(nb->owners+i, NULL, event); > - if (!old) > + if (old == event) > break; > - if (++i == max) > - i = 0; > - } while (i != j); > -done: > - if (!old) > - return &nb->event_constraints[i]; > - > - return &emptyconstraint; > + } > + > + if (new == -1) > + return &emptyconstraint; > + > + return &nb->event_constraints[new]; > } > > static struct amd_nb *amd_alloc_nb(int cpu) > -- > 1.7.9.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
