Re: [PATCH v2] MIPS: tools: Show result for loongson3-llsc-check

[Jiaxun Yang]

ä 2020å5æ2æ GMT+08:00 äå11:55:01, Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> åå:
>It is better to show the result before loongson3-llsc-check exit,
>otherwise we can see nothing if the return status is EXIT_SUCCESS,
>it seems confusing.
>
>E.g. without this patch:
>
>[loongson@localhost tools]$ ./loongson3-llsc-check ../../../vmlinux
>[loongson@localhost tools]$
>
>With this patch:
>
>[loongson@localhost tools]$ ./loongson3-llsc-check ../../../vmlinux
>loongson3-llsc-check returns success
>[loongson@localhost tools]$
>
>Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>

Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>

Btw,
Just learned from Loongson that the latest generation of Loongson-3
doesn't have LLSC errata, also for Loongson 3A R2/R3, use synci instead
of sync would give better performance.

For performance approach, we'd better develop a method
to enable/disable these workarounds at runtime, looks like smp_alternative[1]
that was already employed by x86 and arm64 can be ported to MIPS and
serves to this target.

I'm struggling with device drivers recently so wish somebody
can take a look at it.

Thanks.

[1]: https://lwn.net/Articles/164121/

>---
>
>v2:
>  - move "returns" after "loongson3-llsc-check" suggested by Sergei
>
> arch/mips/tools/loongson3-llsc-check.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/arch/mips/tools/loongson3-llsc-check.c b/arch/mips/tools/loongson3-llsc-check.c
>index 0ebddd0..bdbc7b4 100644
>--- a/arch/mips/tools/loongson3-llsc-check.c
>+++ b/arch/mips/tools/loongson3-llsc-check.c
>@@ -303,5 +303,7 @@ int main(int argc, char *argv[])
> out_close:
> 	close(vmlinux_fd);
> out_ret:
>+	fprintf(stdout, "loongson3-llsc-check returns %s\n",
>+		status ? "failure" : "success");
> 	return status;
> }

-- 
Jiaxun Yang