[v6,31/39] jobstats: use C11 alignas

Message ID 1708971946-18231-32-git-send-email-roretzla@linux.microsoft.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Series use C11 alignas |


Context Check Description
ci/checkpatch success coding style OK

Commit Message

Tyler Retzlaff Feb. 26, 2024, 6:25 p.m. UTC
  The current location used for __rte_aligned(a) for alignment of types
and variables is not compatible with MSVC. There is only a single
location accepted by both toolchains.

For variables standard C11 offers alignas(a) supported by conformant
compilers i.e. both MSVC and GCC.

For types the standard offers no alignment facility that compatibly
interoperates with C and C++ but may be achieved by relocating the
placement of __rte_aligned(a) to the aforementioned location accepted
by all currently supported toolchains.

To allow alignment for both compilers do the following:

* Move __rte_aligned from the end of {struct,union} definitions to
  be between {struct,union} and tag.

  The placement between {struct,union} and the tag allows the desired
  alignment to be imparted on the type regardless of the toolchain being
  used for all of GCC, LLVM, MSVC compilers building both C and C++.

* Replace use of __rte_aligned(a) on variables/fields with alignas(a).

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
 lib/jobstats/rte_jobstats.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)


diff --git a/lib/jobstats/rte_jobstats.h b/lib/jobstats/rte_jobstats.h
index 45b460e..bdd85fe 100644
--- a/lib/jobstats/rte_jobstats.h
+++ b/lib/jobstats/rte_jobstats.h
@@ -32,7 +32,7 @@ 
 typedef void (*rte_job_update_period_cb_t)(struct rte_jobstats *job,
 		int64_t job_result);
-struct rte_jobstats {
+struct __rte_cache_aligned rte_jobstats {
 	uint64_t period;
 	/**< Estimated period of execution. */
@@ -65,9 +65,9 @@  struct rte_jobstats {
 	struct rte_jobstats_context *context;
 	/**< Job stats context object that is executing this job. */
-} __rte_cache_aligned;
-struct rte_jobstats_context {
+struct __rte_cache_aligned rte_jobstats_context {
 	/** Variable holding time at different points:
 	 * -# loop start time if loop was started but no job executed yet.
 	 * -# job start time if job is currently executing.
@@ -111,7 +111,7 @@  struct rte_jobstats_context {
 	uint64_t loop_cnt;
 	/**< Total count of executed loops with at least one executed job. */
-} __rte_cache_aligned;
  * Initialize given context object with default values.