Re: [PATCH 2/3] RISC-V: K210 defconfigs: Drop redundant MEMBARRIER=n

[Palmer Dabbelt]

On Wed, 30 Mar 2022 17:26:45 PDT (-0700), damien.lemoal@xxxxxxxxxxxxxxxxxx wrote:
> On 3/31/22 08:47, Palmer Dabbelt wrote:
> > From: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> >
> > As of 93917ad50972 ("RISC-V: Add support for restartable sequence") we
> > have support for restartable sequences, which default to enabled.  These
> > select MEMBARRIER, so disabling it is now redundant.
> >
> > Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> >
> > ---
> >
> > I'm not actually sure this is the right way to go: presumably the K210
> > defconfigs had MEMBARRIER=n for a reason (maybe just size?), so we might
> > actually want to move to RSEQ=n instead?  As usual: I don't test on the
> > K210, so I'm not exactly sure what the constraints are.
>
> Not sure either. It is like this now because I think this was the default
> at the time the config was created.
>
> Niklas,
>
> Can you test this please ?

Thanks.  I'm OK either way, I guess I'd learn towards turning on the 
features if they work/fit.  I'll hold off on merging this one for a bit, 
I don't see any rush (it's just a defconfig) and if what was there is 
broken then we can take it as a fix.  Otherwise it'll just get rolled up 
into the next round of these, which I'll hopefully remember to do 
earlier next time.

> > ---
> >  arch/riscv/configs/nommu_k210_defconfig        | 1 -
> >  arch/riscv/configs/nommu_k210_sdcard_defconfig | 1 -
> >  arch/riscv/configs/nommu_virt_defconfig        | 1 -
> >  3 files changed, 3 deletions(-)
> >
> > diff --git a/arch/riscv/configs/nommu_k210_defconfig b/arch/riscv/configs/nommu_k210_defconfig
> > index 3f42ed87dde8..2438fa39f8ae 100644
> > --- a/arch/riscv/configs/nommu_k210_defconfig
> > +++ b/arch/riscv/configs/nommu_k210_defconfig
> > @@ -21,7 +21,6 @@ CONFIG_CC_OPTIMIZE_FOR_SIZE=y
> >  # CONFIG_AIO is not set
> >  # CONFIG_IO_URING is not set
> >  # CONFIG_ADVISE_SYSCALLS is not set
> > -# CONFIG_MEMBARRIER is not set
> >  # CONFIG_KALLSYMS is not set
> >  CONFIG_EMBEDDED=y
> >  # CONFIG_VM_EVENT_COUNTERS is not set
> > diff --git a/arch/riscv/configs/nommu_k210_sdcard_defconfig b/arch/riscv/configs/nommu_k210_sdcard_defconfig
> > index af64b95e88cc..9a133e63ae5b 100644
> > --- a/arch/riscv/configs/nommu_k210_sdcard_defconfig
> > +++ b/arch/riscv/configs/nommu_k210_sdcard_defconfig
> > @@ -13,7 +13,6 @@ CONFIG_CC_OPTIMIZE_FOR_SIZE=y
> >  # CONFIG_AIO is not set
> >  # CONFIG_IO_URING is not set
> >  # CONFIG_ADVISE_SYSCALLS is not set
> > -# CONFIG_MEMBARRIER is not set
> >  # CONFIG_KALLSYMS is not set
> >  CONFIG_EMBEDDED=y
> >  # CONFIG_VM_EVENT_COUNTERS is not set
> > diff --git a/arch/riscv/configs/nommu_virt_defconfig b/arch/riscv/configs/nommu_virt_defconfig
> > index e1c9864b6237..5269fbb6b4fc 100644
> > --- a/arch/riscv/configs/nommu_virt_defconfig
> > +++ b/arch/riscv/configs/nommu_virt_defconfig
> > @@ -19,7 +19,6 @@ CONFIG_EXPERT=y
> >  # CONFIG_AIO is not set
> >  # CONFIG_IO_URING is not set
> >  # CONFIG_ADVISE_SYSCALLS is not set
> > -# CONFIG_MEMBARRIER is not set
> >  # CONFIG_KALLSYMS is not set
> >  # CONFIG_VM_EVENT_COUNTERS is not set
> >  # CONFIG_COMPAT_BRK is not set