ec70b05d5d
ETMv3 driver enables PID tracing by directly using perf config from userspace, this means the tracer will capture PID packets from root namespace but the profiling session runs in non-root PID namespace. Finally, the recorded packets can mislead perf reporting with the mismatched PID values. This patch changes to only enable PID tracing for root PID namespace. Note, the hardware supports VMID tracing from ETMv3.5, but the driver never enables VMID trace, this patch doesn't handle VMID trace (bit 30 in ETMCR register) particularly. Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20220204152403.71775-5-leo.yan@linaro.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.