From: Mike Rapoport <rppt@kernel.org>
To: Oscar Salvador <osalvador@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Baoquan He <bhe@redhat.com>, Borislav Petkov <bp@alien8.de>,
David Hildenbrand <david@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
Mike Rapoport <rppt@linux.ibm.com>, Qian Cai <cai@lca.pw>,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org
Subject: Re: [PATCH v3 1/2] x86/setup: don't remove E820_TYPE_RAM for pfn 0
Date: Wed, 13 Jan 2021 13:23:22 +0200 [thread overview]
Message-ID: <20210113112322.GG1106298@kernel.org> (raw)
In-Reply-To: <20210113085644.GA24816@linux>
On Wed, Jan 13, 2021 at 09:56:49AM +0100, Oscar Salvador wrote:
> On Mon, Jan 11, 2021 at 09:40:16PM +0200, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> >
> > The first 4Kb of memory is a BIOS owned area and to avoid its allocation
> > for the kernel it was not listed in e820 tables as memory. As the result,
> > pfn 0 was never recognised by the generic memory management and it is not a
> > part of neither node 0 nor ZONE_DMA.
>
> So, since it never was added to memblock.memory structs, it was not
> initialized by init_unavailable_mem, right?
Actually it was initialized by init_unavailable_mem() and got zone=0 and
node=0, but the DMA zone started from pfn 1, so pfn 0 was never a part of
ZONE_DMA.
> --
> Oscar Salvador
> SUSE L3
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2021-01-13 11:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 19:40 [PATCH v3 0/2] mm: fix initialization of struct page for holes in memory layout Mike Rapoport
2021-01-11 19:40 ` [PATCH v3 1/2] x86/setup: don't remove E820_TYPE_RAM for pfn 0 Mike Rapoport
2021-01-13 8:56 ` Oscar Salvador
2021-01-13 11:23 ` Mike Rapoport [this message]
2021-01-13 12:56 ` David Hildenbrand
2021-01-13 15:35 ` Mike Rapoport
2021-01-21 13:25 ` Borislav Petkov
2021-01-11 19:40 ` [PATCH v3 2/2] mm: fix initialization of struct page for holes in memory layout Mike Rapoport
2021-02-01 9:14 ` David Hildenbrand
2021-02-01 9:39 ` Baoquan He
2021-02-01 14:12 ` Mike Rapoport
2021-01-12 0:58 ` [PATCH v3 0/2] " Andrew Morton
2021-01-12 5:25 ` Mike Rapoport
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