sparc: Don't do expensive hypervisor PCR write unless necessary.
The hypervisor call is only necessary if hypervisor events are
being requested.
So if we're not tracking hypervisor events, simply do a direct
register write.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c
index 8ac23e6..878c682 100644
--- a/arch/sparc/kernel/pcr.c
+++ b/arch/sparc/kernel/pcr.c
@@ -80,8 +80,11 @@
{
unsigned long ret;
- ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val);
- if (ret != HV_EOK)
+ if (val & PCR_N2_HTRACE) {
+ ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val);
+ if (ret != HV_EOK)
+ write_pcr(val);
+ } else
write_pcr(val);
}