From: Douglas Raillard <douglas.raillard@xxxxxxx>
When the alignment is larger than natural, it is very likely that the
source code was using the cacheline size. Therefore, use the cacheline
size when it would only result in increasing the alignment.
Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx>
---
btf_loader.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/btf_loader.c b/btf_loader.c
index e500eae..7a5b16f 100644
--- a/btf_loader.c
+++ b/btf_loader.c
@@ -476,6 +476,7 @@ static uint32_t class__infer_alignment(const struct conf_load *conf,
uint32_t natural_alignment,
uint32_t smallest_offset)
{
+ uint16_t cacheline_size = conf->conf_fprintf->cacheline_size;
uint32_t alignment = 0;
uint32_t offset_delta = byte_offset - smallest_offset;
@@ -494,6 +495,15 @@ static uint32_t class__infer_alignment(const struct conf_load *conf,
/* Natural alignment, nothing to do */
if (alignment <= natural_alignment || alignment == 1)
alignment = 0;
+ /* If the offset is compatible with being aligned on the cacheline size
+ * and this would only result in increasing the alignment, use the
+ * cacheline size as it is safe and quite likely to be what was in the
+ * source.
+ */
+ else if (alignment < cacheline_size &&
+ cacheline_size % alignment == 0 &&
+ byte_offset % cacheline_size == 0)
+ alignment = cacheline_size;
return alignment;
}
--
2.25.1
