]> git.baikalelectronics.ru Git - kernel.git/commit
ramoops: Split ftrace buffer space into per-CPU zones
authorJoel Fernandes <joelaf@google.com>
Thu, 20 Oct 2016 07:34:04 +0000 (00:34 -0700)
committerKees Cook <keescook@chromium.org>
Wed, 16 Nov 2016 00:34:26 +0000 (16:34 -0800)
commitd175ce5ac019e9ebb2d884c0f7503de4ed9ac897
tree9d3c608d505dbebbf58157177467d7d105a195fc
parent526254b65974257e14dd1637b447ed63c9561a5e
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>
Documentation/devicetree/bindings/reserved-memory/ramoops.txt
fs/pstore/ram.c
include/linux/pstore_ram.h