On Thu, 8 Sep 2022 12:10:34 GMT, Martin Doerr <mdo...@openjdk.org> wrote:
>> Robbin Ehn has updated the pull request incrementally with one additional
>> commit since the last revision:
>>
>> Change header and constants handling
>
> We need to support older kernel versions on PPC64 as well. And let's just
> make it usable on PPC64. Improves performance of trivial native calls by
> about 20%.
>
> diff --git a/src/hotspot/cpu/ppc/sharedRuntime_ppc.cpp
> b/src/hotspot/cpu/ppc/sharedRuntime_ppc.cpp
> index 5a55d8f4dc2..0902c0f35ed 100644
> --- a/src/hotspot/cpu/ppc/sharedRuntime_ppc.cpp
> +++ b/src/hotspot/cpu/ppc/sharedRuntime_ppc.cpp
> @@ -2147,7 +2147,9 @@ nmethod
> *SharedRuntime::generate_native_wrapper(MacroAssembler *masm,
> Label no_block, sync;
>
> // Force this write out before the read below.
> - __ fence();
> + if (!UseSystemMemoryBarrier) {
> + __ fence();
> + }
>
> Register sync_state_addr = r_temp_4;
> Register sync_state = r_temp_5;
> diff --git a/src/hotspot/cpu/ppc/templateInterpreterGenerator_ppc.cpp
> b/src/hotspot/cpu/ppc/templateInterpreterGenerator_ppc.cpp
> index bd4e1ce9932..260d99bef81 100644
> --- a/src/hotspot/cpu/ppc/templateInterpreterGenerator_ppc.cpp
> +++ b/src/hotspot/cpu/ppc/templateInterpreterGenerator_ppc.cpp
> @@ -1436,7 +1436,9 @@ address
> TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
> __ li(R0/*thread_state*/, _thread_in_native_trans);
> __ release();
> __ stw(R0/*thread_state*/, thread_(thread_state));
> - __ fence();
> + if (!UseSystemMemoryBarrier) {
> + __ fence();
> + }
>
> // Now before we return to java we must look for a current safepoint
> // (a new safepoint can not start since we entered native_trans).
> diff --git a/src/hotspot/os/linux/systemMemoryBarrier_linux.cpp
> b/src/hotspot/os/linux/systemMemoryBarrier_linux.cpp
> index 796b596c675..66f77818ebc 100644
> --- a/src/hotspot/os/linux/systemMemoryBarrier_linux.cpp
> +++ b/src/hotspot/os/linux/systemMemoryBarrier_linux.cpp
> @@ -35,6 +35,8 @@
> #ifndef SYS_membarrier
> #if defined(AMD64)
> #define SYS_membarrier 324
> + #elif defined(PPC64)
> + #define SYS_membarrier 365
> #else
> #error define SYS_membarrier for the arch
> #endif
>
> Btw. are spaces in front of `#` ok? Some old preprocessors might have
> problems with that.
@TheRealMDoerr thanks, applied.
Do you want to be a reviewer or contributor?
Regarding space:
On Linux we had it for long time I think, see
https://github.com/openjdk/jdk/blob/30d4145e2edd2d3e4cbaa8b01f7639ab53bc0991/src/hotspot/os/linux/os_linux.cpp#L306
-------------
PR: https://git.openjdk.org/jdk/pull/10123
