| Message ID | 20100901225937.18457.16372.stgit@localhost.localdomain |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, 2010-09-01 at 15:59 -0700, Peter P Waskiewicz Jr wrote: > +static int srat_bypass_bios; > + > +static int __init srat_bypass_bios_setup(char *str) > +{ > + srat_bypass_bios = 1; > + return 0; > +} > +early_param("sratbypassbios", srat_bypass_bios_setup); > + > /* Use the information discovered above to actually set up the nodes. */ > int __init acpi_scan_nodes(unsigned long start, unsigned long end) > { I wonder, since all the things using the variable are __init, could it be as well? Just curious really. johannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2010-09-02 at 04:33 -0700, Johannes Berg wrote: > On Wed, 2010-09-01 at 15:59 -0700, Peter P Waskiewicz Jr wrote: > > > +static int srat_bypass_bios; > > + > > +static int __init srat_bypass_bios_setup(char *str) > > +{ > > + srat_bypass_bios = 1; > > + return 0; > > +} > > +early_param("sratbypassbios", srat_bypass_bios_setup); > > + > > /* Use the information discovered above to actually set up the nodes. */ > > int __init acpi_scan_nodes(unsigned long start, unsigned long end) > > { > > I wonder, since all the things using the variable are __init, could it > be as well? Just curious really. That is a good question. It makes sense to me, but I just followed what other boot-time options did, which are not marked __init. I'll defer to anyone else on the list who is better-equipped to answer that. -PJ -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index 7fbbaf8..7863d9c 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -316,3 +316,7 @@ Miscellaneous Do not use GB pages for kernel direct mappings. gbpages Use GB pages for kernel direct mappings. + sratbypassbios + If specified, will skip an SRAT check for PXM coverage + from BIOS enumeration. Only to be used on systems with + buggy BIOSes that munge the SRAT enumeration. diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c index f9897f7..9fa2e32 100644 --- a/arch/x86/mm/srat_64.c +++ b/arch/x86/mm/srat_64.c @@ -351,6 +351,15 @@ int __init acpi_get_nodes(struct bootnode *physnodes) return ret; } +static int srat_bypass_bios; + +static int __init srat_bypass_bios_setup(char *str) +{ + srat_bypass_bios = 1; + return 0; +} +early_param("sratbypassbios", srat_bypass_bios_setup); + /* Use the information discovered above to actually set up the nodes. */ int __init acpi_scan_nodes(unsigned long start, unsigned long end) { @@ -425,9 +434,14 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end) nodes[i].end >> PAGE_SHIFT); /* for out of order entries in SRAT */ sort_node_map(); - if (!nodes_cover_memory(nodes)) { - bad_srat(); - return -1; + if (!srat_bypass_bios) { + if (!nodes_cover_memory(nodes)) { + bad_srat(); + return -1; + } + } else { + printk(KERN_INFO + "SRAT: Bypassing NUMA sanity check...bad BIOS...\n"); } /* Account for nodes with cpus and no memory */
On certain BIOSes, SRAT enumeration isn't exported correctly. This leads to NUMA node enumeration failure, and causes the kernel to fall back onto a single node treated as flat memory. This can happen on large, multi-socket systems (4 or more sockets), and becomes problematic for performance. This patch adds a boot parameter to allow a kernel to be booted with the option to skip the SRAT check. There are BIOSes in production that have these failures, so this will allow people in the field to work around these BIOS issues. Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> --- Documentation/x86/x86_64/boot-options.txt | 4 ++++ arch/x86/mm/srat_64.c | 20 +++++++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html