xiaoxiang781216 commented on PR #8121:
URL: https://github.com/apache/nuttx/pull/8121#issuecomment-1396564883
> @xiaoxiang781216 Could you please share the motivation for disabling this
warning? In which scenario does it manifest?
@gustavonihei here is the warning generated by Candance's clang:
```
[2023-01-19T07:31:49.594Z] media_proxy.c:498:9: error: large atomic
operation may incur significant performance penalty [-Werror,-Watomic-alignment]
[2023-01-19T07:31:49.594Z] if (atomic_load(&priv->refs) == 1 &&
priv->socket) {
[2023-01-19T07:31:49.594Z] ^
```
Here is the related struct definition:
```
typedef struct MediaProxyPriv {
void *proxy;
char *cpu;
uint64_t handle;
atomic_int refs;
int socket;
void *cookie;
media_event_callback event;
} MediaProxyPriv;
```
The warning looks wrong since refs should be naturally alignment.
>
> From this Clang patchset, this warning seems useful:
https://reviews.llvm.org/D45319
>
> > If an atomic variable is misaligned Clang will emit accesses to it as a
libcall. These calls are likely to be slow and involve locks; they are almost
certainly not what the developer intended.
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