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| author | Joel Fernandes <joelagnelf@nvidia.com> | 2026-07-18 13:15:36 -0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2026-07-23 10:39:57 -0700 |
| commit | 34ff636f322c6d5e4f0a52338fa63a7dff09a495 (patch) | |
| tree | 7629759c1ec7148b95bc8ab3080df20a5ecd2273 /Documentation/process/programming-language.rst | |
| download | linux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.tar.gz linux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.zip | |
scftorture: Count single_rpc offline failures in statistics outputgrafted
scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop. As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.
Add the missing accumulation so that the printed value reflects the
actual counts.
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'Documentation/process/programming-language.rst')
| -rw-r--r-- | Documentation/process/programming-language.rst | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/process/programming-language.rst b/Documentation/process/programming-language.rst new file mode 100644 index 000000000..c18e307cc --- /dev/null +++ b/Documentation/process/programming-language.rst @@ -0,0 +1,58 @@ +.. _programming_language: + +Programming Language +==================== + +The Linux kernel is written in the C programming language [c-language]_. +More precisely, it is typically compiled with ``gcc`` [gcc]_ +under ``-std=gnu11`` [gcc-c-dialect-options]_: the GNU dialect of ISO C11. +``clang`` [clang]_ is also supported; see documentation on +:ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. + +This dialect contains many extensions to the language [gnu-extensions]_, +and many of them are used within the kernel as a matter of course. + +Attributes +---------- + +One of the common extensions used throughout the kernel are attributes +[gcc-attribute-syntax]_. Attributes allow to introduce +implementation-defined semantics to language entities (like variables, +functions or types) without having to make significant syntactic changes +to the language (e.g. adding a new keyword) [n2049]_. + +In some cases, attributes are optional (i.e. a compiler not supporting them +should still produce proper code, even if it is slower or does not perform +as many compile-time checks/diagnostics). + +The kernel defines pseudo-keywords (e.g. ``__pure``) instead of using +directly the GNU attribute syntax (e.g. ``__attribute__((__pure__))``) +in order to feature detect which ones can be used and/or to shorten the code. + +Please refer to ``include/linux/compiler_attributes.h`` for more information. + +Rust +---- + +The kernel has support for the Rust programming language +[rust-language]_ under ``CONFIG_RUST``. It is compiled with ``rustc`` [rustc]_ +under ``--edition=2021`` [rust-editions]_. Editions are a way to introduce +small changes to the language that are not backwards compatible. + +On top of that, some unstable features [rust-unstable-features]_ are used in +the kernel. Unstable features may change in the future, thus it is an important +goal to reach a point where only stable features are used. + +Please refer to Documentation/rust/index.rst for more information. + +.. [c-language] http://www.open-std.org/jtc1/sc22/wg14/www/standards +.. [gcc] https://gcc.gnu.org +.. [clang] https://clang.llvm.org +.. [gcc-c-dialect-options] https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html +.. [gnu-extensions] https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html +.. [gcc-attribute-syntax] https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html +.. [n2049] http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2049.pdf +.. [rust-language] https://www.rust-lang.org +.. [rustc] https://doc.rust-lang.org/rustc/ +.. [rust-editions] https://doc.rust-lang.org/edition-guide/editions/ +.. [rust-unstable-features] https://github.com/Rust-for-Linux/linux/issues/2 |
