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Date:   Tue, 27 Jun 2023 00:13:16 +0000
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From:   "Yajun Deng" <yajun.deng@linux.dev>
Message-ID: <a13e81ae159d388d3d3e18978a1b1091@linux.dev>
Subject: Re: [PATCH] memblock: Introduce memblock_reserve_node()
To:     "Mike Rapoport" <rppt@kernel.org>
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
In-Reply-To: <ZJkudvnGz+Tt5Qml@kernel.org>
References: <ZJkudvnGz+Tt5Qml@kernel.org>
 <20230625050850.GJ52412@kernel.org>
 <20230624024622.2959376-1-yajun.deng@linux.dev>
 <4c361d62e0b77242fe4b8592c82c4d90@linux.dev>
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June 26, 2023 2:21 PM, "Mike Rapoport" <rppt@kernel.org> wrote:=0A=0A> On=
 Sun, Jun 25, 2023 at 07:39:10AM +0000, Yajun Deng wrote:=0A> =0A>> June =
25, 2023 1:08 PM, "Mike Rapoport" <rppt@kernel.org> wrote:=0A>> =0A>> On =
Sat, Jun 24, 2023 at 10:46:22AM +0800, Yajun Deng wrote:=0A>> =0A>> It on=
ly returns address now in memblock_find_in_range_node(), we can add a=0A>=
> parameter pointing to integer for node id of the range, which can be us=
ed=0A>> to pass the node id to the new reserve region.=0A>> =0A>> Introdu=
ce memblock_reserve_node() so that the node id can be passed to=0A>> the =
reserve region in memblock_alloc_range_nid().=0A>> =0A>> Signed-off-by: Y=
ajun Deng <yajun.deng@linux.dev>=0A>> =0A>> What problem does this patch =
solve?=0A>> =0A>> If we set nid and flags in memblock_alloc_range_nid(), =
we may not need=0A>> memblock_set_node() in memmap_init_reserved_pages().=
=0A> =0A> When memblock_reserve() is called before NUMA setup, the node i=
ds are still=0A> unset in memblock.memory, so very early reservations wil=
l be missed and we=0A> still have to update node ids in memblock.reserved=
 later.=0A=0AEven so, we still need to pass the 'flags' to the new reserv=
e region.=0Achoose_memblock_flags() may return MEMBLOCK_MIRROR in membloc=
k_alloc_range_nid(),=0Amemblock_reserve() couldn't pass this flag in this=
 case.=0A=0A=0A>> I tested this patch and delete memblock_set_node() in m=
emmap_init_reserved_pages().=0A>> It works fine. I did not delete membloc=
k_set_node() in this patch just in case.=0A> =0A> --=0A> Sincerely yours,=
=0A> Mike.