Messages in this thread Patch in this message | | | Date | Mon, 4 May 2009 20:32:36 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [PATCH] Fix early panic issue on machines with memless node |
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On Tue, 5 May 2009, Zhang, Yanmin wrote:
> Kernel 2.6.30-rc4 panic with boot parameter mem=2G on Nehalem machine. > The machines has 2 nodes and every node has about 3G memory. > > Alex Shi did a good bisect and located the bad patch. > > commit dc098551918093901d8ac8936e9d1a1b891b56ed > Author: Jack Steiner <steiner@sgi.com> > Date: Fri Apr 17 09:22:42 2009 -0500 > > x86/uv: fix init of memory-less nodes > > Add support for nodes that have cpus but no memory. > The current code was failing to add these nodes > to the nodes_present_map. > > v2: Fixes case caught by David Rientjes - missed support > for the x2apic SRAT table. > > [ Impact: fix potential boot crash on memory-less UV nodes. ] > > Reported-by: David Rientjes <rientjes@google.com> > Signed-off-by: Jack Steiner <steiner@sgi.com> > LKML-Reference: <20090417142242.GA23743@sgi.com> > Signed-off-by: Ingo Molnar <mingo@elte.hu> > > > > With earlyprintk boot parameter, we captured below dump info. > > <6>bootmem::alloc_bootmem_core nid=0 size=0 [0 pages] align=1000 goal=1000000 lim0 > PANIC: early exception 06 rip 10:ffffffff80a2fbe4 error 0 cr2 0 > Pid: 0, comm: swapper Not tainted 2.6.30-rc4-ymz #3 > Call Trace: > [<ffffffff80a1a195>] ? early_idt_handler+0x55/0x68 > [<ffffffff80a2fbe4>] ? alloc_bootmem_core+0x91/0x2ae > [<ffffffff80a2fbdc>] ? alloc_bootmem_core+0x89/0x2ae > [<ffffffff80a2fe74>] ? ___alloc_bootmem_nopanic+0x73/0xab > [<ffffffff80a2af73>] ? early_node_mem+0x54/0x78 > [<ffffffff80a2b0ed>] ? setup_node_bootmem+0x156/0x282 > [<ffffffff80a2b880>] ? acpi_scan_nodes+0x207/0x303 > [<ffffffff80a2b255>] ? initmem_init+0x3c/0x14c > [<ffffffff80a1e33b>] ? setup_arch+0x5ba/0x760 > [<ffffffff80a2e904>] ? cgroup_init_subsys+0xfc/0x105 > [<ffffffff80a2ea5f>] ? cgroup_init_early+0x152/0x163 > [<ffffffff80a1a915>] ? start_kernel+0x84/0x35e > [<ffffffff80a1a37e>] ? x86_64_start_kernel+0xe5/0xeb > RIP alloc_bootmem_core+0x91/0x2ae > > Consider below call chain: > acpi_scan_nodes => > setup_node_bootmem > (twice) => early_node_mem > > At begining, acpi_scan_nodes filters out memless nodes by calling > unparse_node. Patch dc098551918 adds the node back actually. > acpi_scan_nodes has many comments around unparse_node. > > Below patch fixes it with node memory checking. Another method is just > to revert the bad patch. > > David Rientjes, Jack Steiner, > Would you check if below patch satisfy your original objective? >
Could you try this instead?
srat: do not register nodes beyond e820 map
The mem= option will truncate the memory map at a specified address so it's not possible to register nodes with memory beyond the e820 upper bound.
unparse_node() is only called when then node had memory associated with it, although with the mem= option it is no longer addressable.
Signed-off-by: David Rientjes <rientjes@google.com> --- diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c --- a/arch/x86/mm/srat_64.c +++ b/arch/x86/mm/srat_64.c @@ -361,6 +361,7 @@ static void __init unparse_node(int node) { int i; node_clear(node, nodes_parsed); + node_clear(node, cpu_nodes_parsed); for (i = 0; i < MAX_LOCAL_APIC; i++) { if (apicid_to_node[i] == node) apicid_to_node[i] = NUMA_NO_NODE; | |