On 13/07/2023 22.23, Richard Henderson wrote:
We adjust CONFIG_ATOMIC128 and CONFIG_CMPXCHG128 with
CONFIG_ATOMIC128_OPT in atomic128.h. It is difficult
to tell when those changes have been applied with the
ifdef we must use with CONFIG_CMPXCHG128. So instead
use HAVE_CMPXCHG128, which triggers -Werror-undef when
the proper header has not been included.
Improves tcg_gen_atomic_cmpxchg_i128 for s390x host, which
requires CONFIG_ATOMIC128_OPT. Without this we fall back
to EXCP_ATOMIC to single-step 128-bit atomics, which is
slow enough to cause some tests to time out.
Reported-by: Thomas Huth <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
---
Thomas, this issue does not quite match the one you bisected, but
other than the cmpxchg, I don't see any see any qemu_{ld,st}_i128
being used in BootLinuxS390X.test_s390_ccw_virtio_tcg.
As far as I can see, this wasn't broken by the addition of
CONFIG_ATOMIC128_OPT, rather that fix didn't go far enough.
Anyway, test_s390_ccw_virtio_tcg now passes in 159s on our host.
Thanks, I can confirm that this fixes the issue for me, too.
Tested-by: Thomas Huth <[email protected]>
