Hi Adrian,

On Sat, Jul 10, 2021 at 03:36:53PM +0300, Adrian Hunter wrote:

On 4/07/21 10:16 am, Leo Yan wrote:

...

Since the __sync functions have been dropped, This patch removes unused build and checking for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT in perf tool.

Note, there have a test for SYNC_COMPARE_AND_SWAP and the test file is located in build/feature/test-sync-compare-and-swap.c. Since there still has several components using the sync functions, it's deliberately to not be removed.

I don't quite follow that. If they aren't using the feature test macro, then why keep the feature test?

There are files are still using __sync_xxx_compare_and_swap() functions, e.g. in the folder tools/testing/selftests/bpf. On the other hand, after drop __sync functions from perf, there have no any Makefile check the feature 'feature-sync-compare-and-swap'. So it's safe to remove the feature test.

Sorry for confusion. Will drop the feature test in new patch set.

Thanks, Leo