Messages in this thread |  | | From | Justin He <> | Subject | RE: [PATCH v3 5/6] device-dax: use fallback nid when numa_node is invalid | Date | Thu, 9 Jul 2020 05:13:19 +0000 |
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Hi Dan
> -----Original Message----- > From: Dan Williams <dan.j.williams@intel.com> > Sent: Thursday, July 9, 2020 11:39 AM > To: Justin He <Justin.He@arm.com> > Cc: Catalin Marinas <Catalin.Marinas@arm.com>; Will Deacon > <will@kernel.org>; Tony Luck <tony.luck@intel.com>; Fenghua Yu > <fenghua.yu@intel.com>; Yoshinori Sato <ysato@users.sourceforge.jp>; Rich > Felker <dalias@libc.org>; Dave Hansen <dave.hansen@linux.intel.com>; Andy > Lutomirski <luto@kernel.org>; Peter Zijlstra <peterz@infradead.org>; > Thomas Gleixner <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; > Borislav Petkov <bp@alien8.de>; David Hildenbrand <david@redhat.com>; X86 > ML <x86@kernel.org>; H. Peter Anvin <hpa@zytor.com>; Vishal Verma > <vishal.l.verma@intel.com>; Dave Jiang <dave.jiang@intel.com>; Andrew > Morton <akpm@linux-foundation.org>; Baoquan He <bhe@redhat.com>; Chuhong > Yuan <hslester96@gmail.com>; Mike Rapoport <rppt@linux.ibm.com>; Logan > Gunthorpe <logang@deltatee.com>; Masahiro Yamada <masahiroy@kernel.org>; > Michal Hocko <mhocko@suse.com>; Linux ARM <linux-arm- > kernel@lists.infradead.org>; Linux Kernel Mailing List <linux- > kernel@vger.kernel.org>; linux-ia64@vger.kernel.org; Linux-sh <linux- > sh@vger.kernel.org>; linux-nvdimm <linux-nvdimm@lists.01.org>; Linux MM > <linux-mm@kvack.org>; Jonathan Cameron <Jonathan.Cameron@huawei.com>; Kaly > Xin <Kaly.Xin@arm.com> > Subject: Re: [PATCH v3 5/6] device-dax: use fallback nid when numa_node is > invalid > > On Wed, Jul 8, 2020 at 7:07 PM Jia He <justin.he@arm.com> wrote: > > > > numa_off is set unconditionally at the end of dummy_numa_init(), > > even with a fake numa node. ACPI detects node id as NUMA_NO_NODE(-1) in > > acpi_map_pxm_to_node() because it regards numa_off as turning off the > numa > > node. Hence dev_dax->target_node is NUMA_NO_NODE on arm64 with fake numa. > > > > Without this patch, pmem can't be probed as a RAM device on arm64 if > SRAT table > > isn't present: > > $ndctl create-namespace -fe namespace0.0 --mode=devdax --map=dev -s 1g - > a 64K > > kmem dax0.0: rejecting DAX region [mem 0x240400000-0x2bfffffff] with > invalid node: -1 > > kmem: probe of dax0.0 failed with error -22 > > > > This fixes it by using fallback memory_add_physaddr_to_nid() as nid. > > > > Suggested-by: David Hildenbrand <david@redhat.com> > > Signed-off-by: Jia He <justin.he@arm.com> > > --- > > drivers/dax/kmem.c | 21 +++++++++++++-------- > > 1 file changed, 13 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > > index 275aa5f87399..218f66057994 100644 > > --- a/drivers/dax/kmem.c > > +++ b/drivers/dax/kmem.c > > @@ -31,22 +31,23 @@ int dev_dax_kmem_probe(struct device *dev) > > int numa_node; > > int rc; > > > > + /* Hotplug starting at the beginning of the next block: */ > > + kmem_start = ALIGN(res->start, memory_block_size_bytes()); > > + > > /* > > * Ensure good NUMA information for the persistent memory. > > * Without this check, there is a risk that slow memory > > * could be mixed in a node with faster memory, causing > > - * unavoidable performance issues. > > + * unavoidable performance issues. Furthermore, fallback node > > + * id can be used when numa_node is invalid. > > */ > > numa_node = dev_dax->target_node; > > if (numa_node < 0) { > > - dev_warn(dev, "rejecting DAX region %pR with invalid > node: %d\n", > > - res, numa_node); > > - return -EINVAL; > > + numa_node = memory_add_physaddr_to_nid(kmem_start); > > I think this fixup belongs to the core to set a fallback value for > dev_dax->target_node. > > I'm close to having patches to provide a functional > phys_addr_to_target_node() for arm64.
Should My this patch(5/6) wait on your new phys_addr_to_target_node() patch? Thanks for the clarification.
-- Cheers, Justin (Jia He)
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