diff options
| -rw-r--r-- | arch/x86_64/mm/srat.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c index 33340bd1e32..9f69d28652f 100644 --- a/arch/x86_64/mm/srat.c +++ b/arch/x86_64/mm/srat.c @@ -91,9 +91,36 @@ static __init inline int srat_disabled(void) return numa_off || acpi_numa < 0; } +/* + * A lot of BIOS fill in 10 (= no distance) everywhere. This messes + * up the NUMA heuristics which wants the local node to have a smaller + * distance than the others. + * Do some quick checks here and only use the SLIT if it passes. + */ +static __init int slit_valid(struct acpi_table_slit *slit) +{ + int i, j; + int d = slit->localities; + for (i = 0; i < d; i++) { + for (j = 0; j < d; j++) { + u8 val = slit->entry[d*i + j]; + if (i == j) { + if (val != 10) + return 0; + } else if (val <= 10) + return 0; + } + } + return 1; +} + /* Callback for SLIT parsing */ void __init acpi_numa_slit_init(struct acpi_table_slit *slit) { + if (!slit_valid(slit)) { + printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n"); + return; + } acpi_slit = slit; } |