From: Andy Whitcroft We have been seeing panics on NUMA systems in pci_call_probe() in 2.6.19-rc1-mm1 and later. This is related to the changes introduced in the commit below: [x86, PCI] Switch pci_bus::sysdata from NUMA node integer to a pointer 0a247a58fc3e2ecfc17654301033e8b8d08df2a2 In this change the sysdata has changed from directly representing a value (the node number in NUMA) to a pointer to a structure. However, it seems that we do not always initialise this sysdata before we probe the device. Prior to the changes above the node was defaulted to 'NULL' allocating the devices to node 0 unconditionally. This patch adds a default sysdata entry (pci_default_sysdata), this is then used where 'NULL' was used previously. pci_default_sysdata defaults the node to unknown (-1). This is a more accurate assignment, mirroring the value returned where no topology support is provided and no locality information is available. There are only two uses of this value in the affected architectures (x86, x86_64) and generic code: 1) in x86_64, dma_alloc_pages() looks up the node in order to allocate node local memory. Here if the node is invalid we will default to the first online node. Behaviour here should be unchanged. 2) in generic, pci_call_probe() looks up the node in order to restrict execution of the probe on the card local node, to favor node local allocation. Where this is unknown previously we would force execution (and thereby allocation) to node 0, this is arguably wrong and using -1 releases this restriction. In an ideal world we should be supplying a sysdata for the appropriate node where it is known. Where it is not known defaulting to -1 seems a better course, and would help us where node 0 is short of memory. Signed-off-by: Andy Whitcroft Cc: Jeff Garzik Cc: Greg KH Signed-off-by: Andrew Morton --- arch/i386/pci/common.c | 2 ++ arch/i386/pci/fixup.c | 8 +++++--- arch/i386/pci/legacy.c | 3 ++- arch/i386/pci/numa.c | 8 +++++--- arch/i386/pci/visws.c | 4 ++-- include/asm-i386/pci.h | 1 + include/asm-x86_64/pci.h | 1 + 7 files changed, 18 insertions(+), 9 deletions(-) diff -puN arch/i386/pci/common.c~pci-device-ensure-sysdata-initialised-v2 arch/i386/pci/common.c --- a/arch/i386/pci/common.c~pci-device-ensure-sysdata-initialised-v2 +++ a/arch/i386/pci/common.c @@ -27,6 +27,8 @@ unsigned long pirq_table_addr; struct pci_bus *pci_root_bus; struct pci_raw_ops *raw_pci_ops; +struct pci_sysdata pci_default_sysdata = { .node = -1 }; + static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value) { return raw_pci_ops->read(pci_domain_nr(bus), bus->number, diff -puN arch/i386/pci/fixup.c~pci-device-ensure-sysdata-initialised-v2 arch/i386/pci/fixup.c --- a/arch/i386/pci/fixup.c~pci-device-ensure-sysdata-initialised-v2 +++ a/arch/i386/pci/fixup.c @@ -25,9 +25,11 @@ static void __devinit pci_fixup_i450nx(s pci_read_config_byte(d, reg++, &subb); DBG("i450NX PXB %d: %02x/%02x/%02x\n", pxb, busno, suba, subb); if (busno) - pci_scan_bus(busno, &pci_root_ops, NULL); /* Bus A */ + pci_scan_bus(busno, &pci_root_ops, + &pci_default_sysdata); /* Bus A */ if (suba < subb) - pci_scan_bus(suba+1, &pci_root_ops, NULL); /* Bus B */ + pci_scan_bus(suba+1, &pci_root_ops, + &pci_default_sysdata); /* Bus B */ } pcibios_last_bus = -1; } @@ -42,7 +44,7 @@ static void __devinit pci_fixup_i450gx(s u8 busno; pci_read_config_byte(d, 0x4a, &busno); printk(KERN_INFO "PCI: i440KX/GX host bridge %s: secondary bus %02x\n", pci_name(d), busno); - pci_scan_bus(busno, &pci_root_ops, NULL); + pci_scan_bus(busno, &pci_root_ops, &pci_default_sysdata); pcibios_last_bus = -1; } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82454GX, pci_fixup_i450gx); diff -puN arch/i386/pci/legacy.c~pci-device-ensure-sysdata-initialised-v2 arch/i386/pci/legacy.c --- a/arch/i386/pci/legacy.c~pci-device-ensure-sysdata-initialised-v2 +++ a/arch/i386/pci/legacy.c @@ -26,7 +26,8 @@ static void __devinit pcibios_fixup_peer l != 0x0000 && l != 0xffff) { DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l); printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n); - pci_scan_bus(n, &pci_root_ops, NULL); + pci_scan_bus(n, &pci_root_ops, + &pci_default_sysdata); break; } } diff -puN arch/i386/pci/numa.c~pci-device-ensure-sysdata-initialised-v2 arch/i386/pci/numa.c --- a/arch/i386/pci/numa.c~pci-device-ensure-sysdata-initialised-v2 +++ a/arch/i386/pci/numa.c @@ -97,9 +97,11 @@ static void __devinit pci_fixup_i450nx(s pci_read_config_byte(d, reg++, &subb); DBG("i450NX PXB %d: %02x/%02x/%02x\n", pxb, busno, suba, subb); if (busno) - pci_scan_bus(QUADLOCAL2BUS(quad,busno), &pci_root_ops, NULL); /* Bus A */ + pci_scan_bus(QUADLOCAL2BUS(quad,busno), &pci_root_ops, + &pci_default_sysdata); /* Bus A */ if (suba < subb) - pci_scan_bus(QUADLOCAL2BUS(quad,suba+1), &pci_root_ops, NULL); /* Bus B */ + pci_scan_bus(QUADLOCAL2BUS(quad,suba+1), &pci_root_ops, + &pci_default_sysdata); /* Bus B */ } pcibios_last_bus = -1; } @@ -124,7 +126,7 @@ static int __init pci_numa_init(void) printk("Scanning PCI bus %d for quad %d\n", QUADLOCAL2BUS(quad,0), quad); pci_scan_bus(QUADLOCAL2BUS(quad,0), - &pci_root_ops, NULL); + &pci_root_ops, &pci_default_sysdata); } return 0; } diff -puN arch/i386/pci/visws.c~pci-device-ensure-sysdata-initialised-v2 arch/i386/pci/visws.c --- a/arch/i386/pci/visws.c~pci-device-ensure-sysdata-initialised-v2 +++ a/arch/i386/pci/visws.c @@ -101,8 +101,8 @@ static int __init pcibios_init(void) "bridge B (PIIX4) bus: %u\n", pci_bus1, pci_bus0); raw_pci_ops = &pci_direct_conf1; - pci_scan_bus(pci_bus0, &pci_root_ops, NULL); - pci_scan_bus(pci_bus1, &pci_root_ops, NULL); + pci_scan_bus(pci_bus0, &pci_root_ops, &pci_default_sysdata); + pci_scan_bus(pci_bus1, &pci_root_ops, &pci_default_sysdata); pci_fixup_irqs(visws_swizzle, visws_map_irq); pcibios_resource_survey(); return 0; diff -puN include/asm-i386/pci.h~pci-device-ensure-sysdata-initialised-v2 include/asm-i386/pci.h --- a/include/asm-i386/pci.h~pci-device-ensure-sysdata-initialised-v2 +++ a/include/asm-i386/pci.h @@ -8,6 +8,7 @@ struct pci_sysdata { int domain; /* PCI domain */ int node; /* NUMA node */ }; +extern struct pci_sysdata pci_default_sysdata; #ifdef CONFIG_PCI_DOMAINS static inline int pci_domain_nr(struct pci_bus *bus) diff -puN include/asm-x86_64/pci.h~pci-device-ensure-sysdata-initialised-v2 include/asm-x86_64/pci.h --- a/include/asm-x86_64/pci.h~pci-device-ensure-sysdata-initialised-v2 +++ a/include/asm-x86_64/pci.h @@ -10,6 +10,7 @@ struct pci_sysdata { int node; /* NUMA node */ void* iommu; /* IOMMU private data */ }; +extern struct pci_sysdata pci_default_sysdata; #ifdef CONFIG_PCI_DOMAINS static inline int pci_domain_nr(struct pci_bus *bus) _