mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-02 07:29:12 -04:00
1b20d9491c
In order to move pointer checks like IS_ERR_VALUE() out of the hotpath and into the reader path of a trace event, user space tools need to be able to parse that. IS_ERR_VALUE() is defined as: #define IS_ERR_VALUE() unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) Which eventually turns into: __builtin_expect(!!((unsigned long)(void *)(x) >= (unsigned long)-4095), 0) Now the traceevent parser can handle most of that except for the __builtin_expect(), which needs to be added. Link: https://lore.kernel.org/linux-mm/20200320055823.27089-3-jaewon31.kim@samsung.com/ Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jaewon Kim <jaewon31.kim@samsung.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Kook <keescook@chromium.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: linux-mm@kvack.org Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/lkml/20200324200956.821799393@goodmis.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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.