1fc7e593e2
The main purpose for using __sync built-in functions is to support compat mode for 32-bit perf with 64-bit kernel. But using these built-in functions might cause potential issues. __sync functions originally support Intel Itanium processoer [1] but it cannot promise to support all 32-bit archs. Now these functions have become the legacy functions. Considering __sync functions cannot really fix the 64-bit value atomicity on 32-bit archs, thus this patch drops __sync functions. Credits to Peter for detailed analysis. [1] https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html#g_t_005f_005fsync-Builtins Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrii Nakryiko <andriin@fb.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel Díaz <daniel.diaz@linaro.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: coresight@lists.linaro.org Cc: x86@kernel.org Link: http://lore.kernel.org/lkml/20210809111407.596077-7-leo.yan@linaro.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.