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Date:   Wed, 25 Aug 2021 19:08:33 +0100
From:   Catalin Marinas <catalin.marinas@arm.com>
To:     Kefeng Wang <wangkefeng.wang@huawei.com>
Cc:     will@kernel.org, ryabinin.a.a@gmail.com, andreyknvl@gmail.com,
        dvyukov@google.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, elver@google.com
Subject: Re: [PATCH v3 2/3] arm64: Support page mapping percpu first chunk
 allocator
Message-ID: <20210825180831.GJ3420@arm.com>
References: <20210809093750.131091-1-wangkefeng.wang@huawei.com>
 <20210809093750.131091-3-wangkefeng.wang@huawei.com>
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On Mon, Aug 09, 2021 at 05:37:49PM +0800, Kefeng Wang wrote:
> Percpu embedded first chunk allocator is the firstly option, but it
> could fails on ARM64, eg,
>   "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000"
>   "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000"
>   "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000"
> 
> then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838",
> even the system could not boot successfully.
> 
> Let's implement page mapping percpu first chunk allocator as a fallback
> to the embedding allocator to increase the robustness of the system.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>