[PATCH 0/2] riscv: Enable percpu page first chunk allocator

[Alexandre Ghiti]

Hi Tejun,

On 10/11/2023 15:07, Alexandre Ghiti wrote:
> While working with pcpu variables, I noticed that riscv did not support
> first chunk allocation in the vmalloc area which may be needed as a fallback
> in case of a sparse NUMA configuration.
>
> patch 1 starts by introducing a new function flush_cache_vmap_early() which
> is needed since a new vmalloc mapping is established and directly accessed:
> on riscv, this would likely fail in case of a reordered access or if the
> uarch caches invalid entries in TLB.
>
> patch 2 simply enables the page percpu first chunk allocator in riscv.
>
> Alexandre Ghiti (2):
>    mm: Introduce flush_cache_vmap_early() and its riscv implementation
>    riscv: Enable pcpu page first chunk allocator
>
>   arch/riscv/Kconfig                  | 2 ++
>   arch/riscv/include/asm/cacheflush.h | 3 ++-
>   arch/riscv/include/asm/tlbflush.h   | 2 ++
>   arch/riscv/mm/kasan_init.c          | 8 ++++++++
>   arch/riscv/mm/tlbflush.c            | 5 +++++
>   include/asm-generic/cacheflush.h    | 6 ++++++
>   mm/percpu.c                         | 8 +-------
>   7 files changed, 26 insertions(+), 8 deletions(-)
>

Any feedback regarding this?

Thanks,

Alex