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| author | Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> | 2014-02-26 04:07:43 +0400 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-03-05 08:55:04 +0400 |
| commit | 1b67bee129a36c22c17186cc2a9981678e9323ee (patch) | |
| tree | af3787d56f78a8f4624aabb7771589deb1428192 /arch/powerpc/include/asm/smp.h | |
| parent | 402d9a1e02f7215628f13b7c80ff3e98c3a0cadc (diff) | |
| download | linux-1b67bee129a36c22c17186cc2a9981678e9323ee.tar.xz | |
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/include/asm/smp.h')
| -rw-r--r-- | arch/powerpc/include/asm/smp.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 9f7356bf6482..ff51046b6466 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -120,7 +120,7 @@ extern int cpu_to_core_id(int cpu); * in /proc/interrupts will be wrong!!! --Troy */ #define PPC_MSG_CALL_FUNCTION 0 #define PPC_MSG_RESCHEDULE 1 -#define PPC_MSG_UNUSED 2 +#define PPC_MSG_TICK_BROADCAST 2 #define PPC_MSG_DEBUGGER_BREAK 3 /* for irq controllers that have dedicated ipis per message (4) */ |