From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Subject: Re: [PATCH v2 06/21] memblock: memblock_phys_alloc_try_nid(): don't panic Date: Fri, 25 Jan 2019 21:32:52 +0200 Message-ID: <20190125193252.GH31519@rapoport-lnx> References: <1548057848-15136-1-git-send-email-rppt@linux.ibm.com> <1548057848-15136-7-git-send-email-rppt@linux.ibm.com> <20190125174502.GL25901@arrakis.emea.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190125174502.GL25901@arrakis.emea.arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Catalin Marinas Cc: linux-mm@kvack.org, Andrew Morton , Christoph Hellwig , "David S. Miller" , Dennis Zhou , Geert Uytterhoeven , Greentime Hu , Greg Kroah-Hartman , Guan Xuetao , Guo Ren , Heiko Carstens , Mark Salter , Matt Turner , Max Filippov , Michael Ellerman , Michal Simek , Paul Burton , Petr Mladek , Rich Felker , Richard Weinberger , Rob Herring , Russell List-Id: devicetree@vger.kernel.org On Fri, Jan 25, 2019 at 05:45:02PM +0000, Catalin Marinas wrote: > On Mon, Jan 21, 2019 at 10:03:53AM +0200, Mike Rapoport wrote: > > diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c > > index ae34e3a..2c61ea4 100644 > > --- a/arch/arm64/mm/numa.c > > +++ b/arch/arm64/mm/numa.c > > @@ -237,6 +237,10 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn) > > pr_info("Initmem setup node %d []\n", nid); > > > > nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid); > > + if (!nd_pa) > > + panic("Cannot allocate %zu bytes for node %d data\n", > > + nd_size, nid); > > + > > nd = __va(nd_pa); > > > > /* report and initialize */ > > Does it mean that memblock_phys_alloc_try_nid() never returns valid > physical memory starting at 0? Yes, it does. memblock_find_in_range_node() that is used by all allocation methods skips the first page [1]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/memblock.c#n257 > -- > Catalin > -- Sincerely yours, Mike.