linux-kernel - Re: [PATCH v2 2/3] riscv: End kernel region search in setup

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Date:   Sun, 16 Feb 2020 09:42:17 -0500
From:   Alex Ghiti <alex@...ti.fr>
To:     Jan Kiszka <jan.kiszka@....de>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        linux-riscv@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/3] riscv: End kernel region search in setup_bootmem
 earlier

Hi Jan,

On 2/15/20 6:49 AM, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@...mens.com>
> 
> No need to look further when that single region is found.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
> =2D--
>   arch/riscv/mm/init.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index aec39a56d6cf..a774547e9021 100644
> =2D-- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -160,6 +160,8 @@ void __init setup_bootmem(void)
>   			if (reg->base + mem_size < end)
>   				memblock_remove(reg->base + mem_size,
>   						end - reg->base - mem_size);
> +
> +			break;
>   		}
>   	}
>   	BUG_ON(mem_size =3D=3D 0);
> =2D-
> 2.16.4
> 
> 

I was looking at the test above that determines if the current memblock 
contains the kernel:

if (reg->base <= vmlinux_end && vmlinux_end <= end)

Shouldn't it be:

if (reg->base <= vmlinux_start && vmlinux_end <= end)

?

Otherwise, we can indeed stop as soon as we found the region containing 
the kernel, so feel free to add:

Reviewed-by: Alexandre Ghiti <alex@...ti.fr>

Thanks,

Alex