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

From: Dennis Zhou <dennis@kernel.org>
To: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	Alexander Potapenko <glider@google.com>,
	Andrey Konovalov <andreyknvl@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
	Christoph Lameter <cl@linux.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	kasan-dev@googlegroups.com, linux-arch@vger.kernel.org,
	linux-mm@kvack.org
Subject: Re: [PATCH 0/2] riscv: Enable percpu page first chunk allocator
Date: Thu, 7 Dec 2023 23:17:23 -0800	[thread overview]
Message-ID: <ZXLDA3zObbLybTJB@snowbird> (raw)
In-Reply-To: <20231110140721.114235-1-alexghiti@rivosinc.com>

Hello,

On Fri, Nov 10, 2023 at 03:07:19PM +0100, 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(-)
> 
> -- 
> 2.39.2
> 

I've applied this to percpu#for-6.8.

Thanks,
Dennis