AcoSail/kernel_optimize_test
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sparc: Don't do expensive hypervisor PCR write unless necessary.

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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>
This commit is contained in:
David S. Miller 2011-07-27 20:46:25 -07:00
parent 15e3608d7c
commit 314ff52727
1 changed files with 5 additions and 2 deletions
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7
arch/sparc/kernel/pcr.c
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@ -80,8 +80,11 @@ static void n2_pcr_write(u64 val)
{
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);
}