From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, Baoquan He <bhe@redhat.com>,
Mike Rapoport <rppt@kernel.org>
Subject: Re: [PATCH -next] mm: page_alloc: simplify has_managed_dma()
Date: Tue, 30 May 2023 10:10:52 +0800 [thread overview]
Message-ID: <38ea4ea3-cd7f-abf4-e992-2f748e3b1fcb@huawei.com> (raw)
In-Reply-To: <ZHS2AgVvrT3n/hlM@casper.infradead.org>
On 2023/5/29 22:26, Matthew Wilcox wrote:
> On Mon, May 29, 2023 at 10:40:22PM +0800, Kefeng Wang wrote:
>> The ZONE_DMA should only exists on Node 0, only check NODE_DATA(0)
>> is enough, so simplify has_managed_dma() and make it inline.
>
> That's true on x86, but is it true on all architectures?
There is no document about numa node info for the DMA_ZONE, + Mike
I used 'git grep -w ZONE_DMA arch/'
1) the following archs without NUMA support, so it's true for them,
arch/alpha/mm/init.c: max_zone_pfn[ZONE_DMA] = dma_pfn;
arch/arm/mm/init.c: max_zone_pfn[ZONE_DMA] = min(arm_dma_pfn_limit,
max_low);
arch/m68k/mm/init.c: max_zone_pfn[ZONE_DMA] = end_mem >> PAGE_SHIFT;
arch/m68k/mm/mcfmmu.c: max_zone_pfn[ZONE_DMA] = PFN_DOWN(_ramend);
arch/m68k/mm/motorola.c: max_zone_pfn[ZONE_DMA] = memblock_end_of_DRAM();
arch/m68k/mm/sun3mmu.c: max_zone_pfn[ZONE_DMA] = ((unsigned
long)high_memory) >> PAGE_SHIFT;
arch/microblaze/mm/init.c: zones_size[ZONE_DMA] = max_low_pfn;
arch/microblaze/mm/init.c: zones_size[ZONE_DMA] = max_pfn;
2) Simple check following archs, it seems that it is yes to them too.
arch/mips/mm/init.c: max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
arch/powerpc/mm/mem.c: max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
arch/s390/mm/init.c: max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
arch/sparc/mm/srmmu.c: max_zone_pfn[ZONE_DMA] = max_low_pfn;
arch/x86/mm/init.c: max_zone_pfns[ZONE_DMA] = min(MAX_DMA_PFN,
max_low_pfn);
arch/arm64/mm/init.c: max_zone_pfns[ZONE_DMA] =
PFN_DOWN(arm64_dma_phys_limit);
arch/loongarch/mm/init.c: max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
next prev parent reply other threads:[~2023-05-30 2:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-29 14:40 [PATCH -next] mm: page_alloc: simplify has_managed_dma() Kefeng Wang
2023-05-29 14:26 ` Matthew Wilcox
2023-05-30 2:10 ` Kefeng Wang [this message]
2023-05-30 4:18 ` Baoquan He
2023-05-30 6:40 ` Kefeng Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=38ea4ea3-cd7f-abf4-e992-2f748e3b1fcb@huawei.com \
--to=wangkefeng.wang@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=bhe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rppt@kernel.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).