From: Alex Thorlton Date: Thu, 18 Dec 2014 18:44:30 +0000 (-0600) Subject: sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b74e6278fd6db5848163ccdc6e9d8eb6efdee9bd;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation When allocating space for load_balance_mask, in sched_init, when CPUMASK_OFFSTACK is set, we've managed to spill over KMALLOC_MAX_SIZE on our 6144 core machine. The patch below breaks up the allocations so that they don't overflow the max alloc size. It also allocates the masks on the the node from which they'll most commonly be accessed, to minimize remote accesses on NUMA machines. Suggested-by: George Beshers Signed-off-by: Alex Thorlton Cc: George Beshers Cc: Russ Anderson Cc: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1418928270-148543-1-git-send-email-athorlton@sgi.com Signed-off-by: Ingo Molnar --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b5797b78add6..c0accc00566e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7112,9 +7112,6 @@ void __init sched_init(void) #endif #ifdef CONFIG_RT_GROUP_SCHED alloc_size += 2 * nr_cpu_ids * sizeof(void **); -#endif -#ifdef CONFIG_CPUMASK_OFFSTACK - alloc_size += num_possible_cpus() * cpumask_size(); #endif if (alloc_size) { ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); @@ -7135,13 +7132,13 @@ void __init sched_init(void) ptr += nr_cpu_ids * sizeof(void **); #endif /* CONFIG_RT_GROUP_SCHED */ + } #ifdef CONFIG_CPUMASK_OFFSTACK - for_each_possible_cpu(i) { - per_cpu(load_balance_mask, i) = (void *)ptr; - ptr += cpumask_size(); - } -#endif /* CONFIG_CPUMASK_OFFSTACK */ + for_each_possible_cpu(i) { + per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node( + cpumask_size(), GFP_KERNEL, cpu_to_node(i)); } +#endif /* CONFIG_CPUMASK_OFFSTACK */ init_rt_bandwidth(&def_rt_bandwidth, global_rt_period(), global_rt_runtime());