diff options
| author | Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> | 2014-02-26 05:37:43 +0530 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-03-05 15:55:04 +1100 |
| commit | 1b67bee129a36c22c17186cc2a9981678e9323ee (patch) | |
| tree | af3787d56f78a8f4624aabb7771589deb1428192 /arch/powerpc/platforms | |
| parent | 402d9a1e02f7215628f13b7c80ff3e98c3a0cadc (diff) | |
| download | linux-1b67bee129a36c22c17186cc2a9981678e9323ee.tar.bz2 | |
powerpc: Implement tick broadcast IPI as a fixed IPI message
For scalability and performance reasons, we want the tick broadcast IPIs
to be handled as efficiently as possible. Fixed IPI messages
are one of the most efficient mechanisms available - they are faster than
the smp_call_function mechanism because the IPI handlers are fixed and hence
they don't involve costly operations such as adding IPI handlers to the target
CPU's function queue, acquiring locks for synchronization etc.
Luckily we have an unused IPI message slot, so use that to implement
tick broadcast IPIs efficiently.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[Functions renamed to tick_broadcast* and Changelog modified by
Preeti U. Murthy<preeti@linux.vnet.ibm.com>]
Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Geoff Levand <geoff@infradead.org> [For the PS3 part]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/cell/interrupt.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/ps3/smp.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c index adf372606a1c..8a106b4172e0 100644 --- a/arch/powerpc/platforms/cell/interrupt.c +++ b/arch/powerpc/platforms/cell/interrupt.c @@ -215,7 +215,7 @@ void iic_request_IPIs(void) { iic_request_ipi(PPC_MSG_CALL_FUNCTION); iic_request_ipi(PPC_MSG_RESCHEDULE); - iic_request_ipi(PPC_MSG_UNUSED); + iic_request_ipi(PPC_MSG_TICK_BROADCAST); iic_request_ipi(PPC_MSG_DEBUGGER_BREAK); } diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c index 00d1a7c2a5a4..b358bec6c8cb 100644 --- a/arch/powerpc/platforms/ps3/smp.c +++ b/arch/powerpc/platforms/ps3/smp.c @@ -76,7 +76,7 @@ static int __init ps3_smp_probe(void) BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION != 0); BUILD_BUG_ON(PPC_MSG_RESCHEDULE != 1); - BUILD_BUG_ON(PPC_MSG_UNUSED != 2); + BUILD_BUG_ON(PPC_MSG_TICK_BROADCAST != 2); BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3); for (i = 0; i < MSG_COUNT; i++) { |