linux-toradex.git/Documentation/devicetree/bindings/reserved-memory, branch v4.10 Linux kernel for Apalis and Colibri modules ramoops: Split ftrace buffer space into per-CPU zones 2016-11-16T00:34:26+00:00 Joel Fernandes joelaf@google.com 2016-10-20T07:34:04+00:00 a1cf53ac6d156721afa86453d5e8423461881231 If the RAMOOPS_FLAG_FTRACE_PER_CPU flag is passed to ramoops pdata, split the ftrace space into multiple zones depending on the number of CPUs. This speeds up the performance of function tracing by about 280% in my tests as we avoid the locking. The trade off being lesser space available per CPU. Let the ramoops user decide which option they want based on pdata flag. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: added max_ftrace_cnt to track size, added DT logic and docs] Signed-off-by: Kees Cook <keescook@chromium.org> 
If the RAMOOPS_FLAG_FTRACE_PER_CPU flag is passed to ramoops pdata, split
the ftrace space into multiple zones depending on the number of CPUs.

This speeds up the performance of function tracing by about 280% in my
tests as we avoid the locking. The trade off being lesser space available
per CPU. Let the ramoops user decide which option they want based on pdata
flag.

Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: added max_ftrace_cnt to track size, added DT logic and docs]
Signed-off-by: Kees Cook <keescook@chromium.org>
ramoops: use DT reserved-memory bindings 2016-08-05T18:21:36+00:00 Kees Cook keescook@chromium.org 2016-07-30T01:11:32+00:00 529182e204db083cb7bda832d1c5c6d9278ba1cb Instead of a ramoops-specific node, use a child node of /reserved-memory. This requires that of_platform_device_create() be explicitly called for the node, though, since "/reserved-memory" does not have its own "compatible" property. Suggested-by: Rob Herring <robh@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rob Herring <robh@kernel.org> 
Instead of a ramoops-specific node, use a child node of /reserved-memory.
This requires that of_platform_device_create() be explicitly called
for the node, though, since "/reserved-memory" does not have its own
"compatible" property.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
of: document bindings for reserved-memory nodes 2014-03-04T08:44:23+00:00 Grant Likely grant.likely@linaro.org 2014-02-28T13:42:46+00:00 f08ad1deaaf83b7e7369716949b34dadc530be01 Reserved memory nodes allow for the reservation of static (fixed address) regions, or dynamically allocated regions for a specific purpose. [joshc: Based on binding document proposed (in non-patch form) here: http://lkml.kernel.org/g/20131030134702.19B57C402A0@trevor.secretlab.ca adapted to support #memory-region-cells] Signed-off-by: Josh Cartwright <joshc@codeaurora.org> [mszyprow: removed #memory-region-cells property] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> [grant.likely: removed residual #memory-region-cells example] Signed-off-by: Grant Likely <grant.likely@linaro.org> 
Reserved memory nodes allow for the reservation of static (fixed
address) regions, or dynamically allocated regions for a specific
purpose.

[joshc: Based on binding document proposed (in non-patch form) here:
 http://lkml.kernel.org/g/20131030134702.19B57C402A0@trevor.secretlab.ca
 adapted to support #memory-region-cells]
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
[mszyprow: removed #memory-region-cells property]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
[grant.likely: removed residual #memory-region-cells example]
Signed-off-by: Grant Likely <grant.likely@linaro.org>