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| author | Rashmica Gupta <rashmica.g@gmail.com> | 2017-06-01 08:34:38 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-24 15:14:38 +0300 |
| commit | 9d5171a8f248b1b0e69329bf141e17645c0324a0 (patch) | |
| tree | d7b7336097434b19190e69dc1bf5cbef317c133b /arch/powerpc/platforms/powernv/Kconfig | |
| parent | 2dea1d9c38e481051fa0e62807e518c5768e62dd (diff) | |
| download | linux-9d5171a8f248b1b0e69329bf141e17645c0324a0.tar.xz | |
powerpc/powernv: Enable removal of memory for in memory tracing
The hardware trace macro feature requires access to a chunk of real
memory. This patch provides a debugfs interface to do this. By
writing an integer containing the size of memory to be unplugged into
/sys/kernel/debug/powerpc/memtrace/enable, the code will attempt to
remove that much memory from the end of each NUMA node.
This patch also adds additional debugsfs files for each node that
allows the tracer to interact with the removed memory, as well as
a trace file that allows userspace to read the generated trace.
Note that this patch does not invoke the hardware trace macro, it
only allows memory to be removed during runtime for the trace macro
to utilise.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
[mpe: Minor formatting etc fixups]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/powernv/Kconfig')
| -rw-r--r-- | arch/powerpc/platforms/powernv/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig index 6a6f4ef46b9e..d7bacb20529c 100644 --- a/arch/powerpc/platforms/powernv/Kconfig +++ b/arch/powerpc/platforms/powernv/Kconfig @@ -30,3 +30,11 @@ config OPAL_PRD help This enables the opal-prd driver, a facility to run processor recovery diagnostics on OpenPower machines + +config PPC_MEMTRACE + bool "Enable removal of RAM from kernel mappings for tracing" + depends on PPC_POWERNV && MEMORY_HOTREMOVE + default n + help + Enabling this option allows for the removal of memory (RAM) + from the kernel mappings to be used for hardware tracing. |