Perf uses a hard coded string "RSDTtXZPI" to index the sched_switch prev_state field raw bitmask value. This works well except for when the kernel changes this string, in which case this will break again. Instead we add a new way to parse task state string from tracepoint print format already recorded by perf, which eliminates the further dependencies with this hardcode and unmaintainable macro, and this is exactly what libtraceevent[1] does for now. So we borrow the print flags parsing logic from libtraceevent[1]. And in get_states(), we walk the print arguments until the __print_flags() for the target state field is found, and use that to build the states string for future parsing. [1]: https://lore.kernel.org/linux-trace-devel/20231224140732.7d41698d@rorschach.local.home/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Ze Gao <zegao@tencent.com> Link: https://lore.kernel.org/r/20240122070859.1394479-4-zegao@tencent.com Signed-off-by: Namhyung Kim <namhyung@kernel.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.
Description
Languages
C
97.6%
Assembly
1%
Shell
0.5%
Python
0.3%
Makefile
0.3%