Re: [PATCH v4 5/7] RISC-V: Move to generic spinlocks

From: Heiko Stübner
Date: Wed May 04 2022 - 08:03:03 EST


Am Samstag, 30. April 2022, 17:36:24 CEST schrieb Palmer Dabbelt:
> From: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
>
> Our existing spinlocks aren't fair and replacing them has been on the
> TODO list for a long time. This moves to the recently-introduced ticket
> spinlocks, which are simple enough that they are likely to be correct
> and fast on the vast majority of extant implementations.
>
> This introduces a horrible hack that allows us to split out the spinlock
> conversion from the rwlock conversion. We have to do the spinlocks
> first because qrwlock needs fair spinlocks, but we don't want to pollute
> the asm-generic code to support the generic spinlocks without qrwlocks.
> Thus we pollute the RISC-V code, but just until the next commit as it's
> all going away.
>
> Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>

on riscv64+riscv32 qemu, beaglev and d1-nezha

Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>