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authorJoel Fernandes <joelaf@google.com>2016-10-20 09:34:04 +0200
committerKees Cook <keescook@chromium.org>2016-11-16 01:34:26 +0100
commita1cf53ac6d156721afa86453d5e8423461881231 (patch)
tree9d3c608d505dbebbf58157177467d7d105a195fc /Documentation
parentpstore: Make ramoops_init_przs generic for other prz arrays (diff)
downloadlinux-a1cf53ac6d156721afa86453d5e8423461881231.tar.xz
linux-a1cf53ac6d156721afa86453d5e8423461881231.zip
ramoops: Split ftrace buffer space into per-CPU zones
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/ramoops.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
index e81f821a2135..0eba562fe5c6 100644
--- a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
+++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
@@ -46,3 +46,6 @@ Optional properties:
(defaults to buffered mappings)
- no-dump-oops: if present, only dump panics (defaults to panics and oops)
+
+- flags: if present, pass ramoops behavioral flags (defaults to 0,
+ see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values).