linux-kernel - Re: [PATCH v2 2/2] mm: Create non-atomic version of SetPageReserved for init use

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Date:   Thu, 6 Sep 2018 07:49:46 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Alexander Duyck <alexander.duyck@...il.com>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        alexander.h.duyck@...el.com, pavel.tatashin@...rosoft.com,
        dave.hansen@...el.com, akpm@...ux-foundation.org, mingo@...nel.org,
        kirill.shutemov@...ux.intel.com
Subject: Re: [PATCH v2 2/2] mm: Create non-atomic version of SetPageReserved
 for init use

On Wed 05-09-18 14:13:34, Alexander Duyck wrote:
[...]

just a nit

> @@ -1231,7 +1231,8 @@ void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
>  			/* Avoid false-positive PageTail() */
>  			INIT_LIST_HEAD(&page->lru);
>  
> -			SetPageReserved(page);
> +			/* no need for atomic set_bit at init time */
> +			__SetPageReserved(page);

OK but I guess it would be much more clear to say
			/*
			 * no need for atomic set_bit because the struct
			 * page is not visible yet so nobody should
			 * access it yet.
			 */
>  		}
>  	}
>  }
-- 
Michal Hocko
SUSE Labs