[MIPS] SMTC: Instant IPI replay.
SMTC pseudo-interrupts between TCs are deferred and queued if the target
TC is interrupt-inhibited (IXMT). In the first SMTC prototypes, these
queued IPIs were serviced on return to user mode, or on entry into the
kernel idle loop. The INSTANT_REPLAY option dispatches them as part of
local_irq_restore() processing, which adds runtime overhead (hence the
option to turn it off), but ensures that IPIs are handled promptly even
under heavy I/O interrupt load.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index fd2ff06..bbd386f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1568,6 +1568,20 @@
depends on MIPS_MT
default y
+config MIPS_MT_SMTC_INSTANT_REPLAY
+ bool "Low-latency Dispatch of Deferred SMTC IPIs"
+ depends on MIPS_MT_SMTC
+ default y
+ help
+ SMTC pseudo-interrupts between TCs are deferred and queued
+ if the target TC is interrupt-inhibited (IXMT). In the first
+ SMTC prototypes, these queued IPIs were serviced on return
+ to user mode, or on entry into the kernel idle loop. The
+ INSTANT_REPLAY option dispatches them as part of local_irq_restore()
+ processing, which adds runtime overhead (hence the option to turn
+ it off), but ensures that IPIs are handled promptly even under
+ heavy I/O interrupt load.
+
config MIPS_VPE_LOADER_TOM
bool "Load VPE program into memory hidden from linux"
depends on MIPS_VPE_LOADER