Messages in this thread Patch in this message | | | From | Andrew Banman <> | Subject | [PATCH v2] x86/platform/uv/BAU: disable BAU on single hub configurations | Date | Thu, 20 Jul 2017 17:05:51 -0500 |
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The BAU confers no benefit to a UV system running with only one hub/socket. Permanently disable the BAU driver if there are less than two hubs online to avoid BAU overhead. We have observed failed boots on single-socket UV4 systems caused by BAU that are avoided with this patch.
Version 2: Consolidate initialization error blocks with goto err_bau_disable and free the per_cpu cpumasks to fix a memory leak.
Signed-off-by: Andrew Banman <abanman@hpe.com> Acked-by: Russ Anderson <rja@hpe.com> Acked-by: Mike Travis <mike.travis@hpe.com> --- arch/x86/platform/uv/tlb_uv.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 2511a28..e4a51a6 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -2245,13 +2245,17 @@ static int __init uv_bau_init(void) else if (is_uv1_hub()) ops = uv1_bau_ops; + nuvhubs = uv_num_possible_blades(); + if (nuvhubs < 2) { + pr_crit("UV: BAU disabled - insufficient hub count\n"); + goto err_bau_disable; + } + for_each_possible_cpu(cur_cpu) { mask = &per_cpu(uv_flush_tlb_mask, cur_cpu); zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cur_cpu)); } - nuvhubs = uv_num_possible_blades(); - uv_base_pnode = 0x7fffffff; for (uvhub = 0; uvhub < nuvhubs; uvhub++) { cpus = uv_blade_nr_possible_cpus(uvhub); @@ -2264,9 +2268,8 @@ static int __init uv_bau_init(void) enable_timeouts(); if (init_per_cpu(nuvhubs, uv_base_pnode)) { - set_bau_off(); - nobau_perm = 1; - return 0; + pr_crit("UV: BAU disabled - per CPU init failed\n"); + goto err_bau_disable; } vector = UV_BAU_MESSAGE; @@ -2292,6 +2295,14 @@ static int __init uv_bau_init(void) } return 0; + +err_bau_disable: + for_each_possible_cpu(cur_cpu) { + free_cpumask_var(per_cpu(uv_flush_tlb_mask, cur_cpu)); + } + set_bau_off(); + nobau_perm = 1; + return -EINVAL; } core_initcall(uv_bau_init); fs_initcall(uv_ptc_init); -- 1.8.2.1
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