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powerpc: Avoid extra indirect function call in sending IPIs

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On many platforms (including pSeries), smp_ops->message_pass is always
smp_muxed_ipi_message_pass.  This changes arch/powerpc/kernel/smp.c so
that if smp_ops->message_pass is NULL, it calls smp_muxed_ipi_message_pass
directly.

This means that a platform doesn't need to set both .message_pass and
.cause_ipi, only one of them.  It is a slight performance improvement
in that it gets rid of an indirect function call at the expense of a
predictable conditional branch.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Paul Mackerras
2011-05-25 23:34:12 +00:00
committed by Benjamin Herrenschmidt
parent 7ac87abb81
commit 9ca980dce5
6 changed files with 19 additions and 9 deletions
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2
arch/powerpc/platforms/pseries/smp.c
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@@ -207,7 +207,7 @@ static struct smp_ops_t pSeries_mpic_smp_ops = {
};
static struct smp_ops_t pSeries_xics_smp_ops = {
.message_pass = smp_muxed_ipi_message_pass,
.message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
.probe = xics_smp_probe,
.kick_cpu = smp_pSeries_kick_cpu,