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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-17 17:43:59 (GMT) |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-26 04:37:27 (GMT) |
commit | 5d38902c483881645ba16058cffaa478b81e5cfa (patch) | |
tree | 1ed21b6a245c772a6d86cac7cd8ebe566dd970bb /arch/powerpc/Kconfig | |
parent | 04a85d1234d7e1682a612565e663e6b760918643 (diff) | |
download | linux-5d38902c483881645ba16058cffaa478b81e5cfa.tar.xz |
powerpc: Add irqtrace support for 32-bit powerpc
Based on initial work from: Dale Farnsworth <dale@farnsworth.org>
Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.
The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.
There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/Kconfig')
-rw-r--r-- | arch/powerpc/Kconfig | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index bf6cedf..d00131c 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -62,7 +62,6 @@ config HAVE_LATENCYTOP_SUPPORT config TRACE_IRQFLAGS_SUPPORT bool - depends on PPC64 default y config LOCKDEP_SUPPORT |