[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20231123101854.GF636165@kernel.org>
Date: Thu, 23 Nov 2023 12:18:54 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Serge Semin <fancer.lancer@...il.com>
Cc: Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Andrew Morton <akpm@...ux-foundation.org>,
Matthew Wilcox <willy@...radead.org>,
Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>,
Arnd Bergmann <arnd@...db.de>,
Aleksandar Rikalo <aleksandar.rikalo@...mia.com>,
Aleksandar Rikalo <arikalo@...il.com>,
Dragan Mladjenovic <dragan.mladjenovic@...mia.com>,
Chao-ying Fu <cfu@...ecomp.com>,
Jiaxun Yang <jiaxun.yang@...goat.com>,
Yinglu Yang <yangyinglu@...ngson.cn>,
Tiezhu Yang <yangtiezhu@...ngson.cn>,
Marc Zyngier <maz@...nel.org>, linux-mips@...r.kernel.org,
linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/7] mm/mm_init.c: Extend init unavailable range doc info
Hi Serge,
On Wed, Nov 22, 2023 at 09:24:03PM +0300, Serge Semin wrote:
> Besides of the already described reasons the pages backended memory holes
> might be persistent due to having memory mapped IO spaces behind those
> ranges in the framework of flatmem kernel config. Add such note to the
> init_unavailable_range() method kdoc in order to point out to one more
> reason of having the function executed for such regions.
>
> Signed-off-by: Serge Semin <fancer.lancer@...il.com>
>
> ---
>
> Please let me know if the IO-space pages must be initialized somehow
> differently rather relying on free_area_init() executing the
> init_unavailable_range() method.
Maybe I'm missing something, but why do you need struct pages in the
IO space?
> ---
> mm/mm_init.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 077bfe393b5e..3fa33e2d32ba 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -796,6 +796,7 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn)
> * - physical memory bank size is not necessarily the exact multiple of the
> * arbitrary section size
> * - early reserved memory may not be listed in memblock.memory
> + * - memory mapped IO space
> * - memory layouts defined with memmap= kernel parameter may not align
> * nicely with memmap sections
> *
> --
> 2.42.1
>
--
Sincerely yours,
Mike.
Powered by blists - more mailing lists