We have encountered hardware with 18 cores/socket that gives 36 CPUs/socket with hyperthreading enabled. This exceeds the current MAX_CPUS_PER_SOCKET causing a failure in get_cpu_topology. Increase MAX_CPUS_PER_SOCKET to 64 and MAX_CPUS_PER_UVHUB to 128.
Additionally, this exposed another bug. When get_cpu_topology fails, we need to make sure that we do not use bau_control->statp (e.g. when a user reads /proc/sgi_uv/ptc_statistics causing ptc_seq_show to be invoked). In uv_bau_init we call set_bau_off() when init_per_cpu()->get_cpu_topology() fails -- therefore, to avoid referencing a NULL pointer we add code that detects when the bau is off and print out the bau is disabled. Signed-off-by: James Custer <[email protected]> --- arch/x86/include/asm/uv/uv_bau.h | 4 ++-- arch/x86/platform/uv/tlb_uv.c | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/uv/uv_bau.h b/arch/x86/include/asm/uv/uv_bau.h index 2d60a78..fc808b8 100644 --- a/arch/x86/include/asm/uv/uv_bau.h +++ b/arch/x86/include/asm/uv/uv_bau.h @@ -33,8 +33,8 @@ * Each of the descriptors is 64 bytes in size (8*64 = 512 bytes in a set). */ -#define MAX_CPUS_PER_UVHUB 64 -#define MAX_CPUS_PER_SOCKET 32 +#define MAX_CPUS_PER_UVHUB 128 +#define MAX_CPUS_PER_SOCKET 64 #define ADP_SZ 64 /* hardware-provided max. */ #define UV_CPUS_PER_AS 32 /* hardware-provided max. */ #define ITEMS_PER_DESC 8 diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 3968d67..570b1b1 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1384,6 +1384,10 @@ static int ptc_seq_show(struct seq_file *file, void *data) } if (cpu < num_possible_cpus() && cpu_online(cpu)) { bcp = &per_cpu(bau_control, cpu); + if (bcp->nobau) { + seq_printf(file, "cpu %d bau disabled\n", cpu); + return 0; + } stat = bcp->statp; /* source side statistics */ seq_printf(file, -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
