Messages in this thread | | | Date | Wed, 20 Mar 2024 10:03:02 +0100 | Subject | Re: [PATCH] cpumask: Create dedicated kmem cache for cpumask var | From | Rasmus Villemoes <> |
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On 19/03/2024 13.24, Dawei Li wrote: > alloc_cpumask_var_node() and friends allocate cpumask var dynamically > for CONFIG_CPUMASK_OFFSTACK=y kernel. The allocated size of cpumask var > is cpumask_size(), which is runtime constant after nr_cpu_ids is > freezed. > > Create a dedicated kmem cache for dynamic allocation of cpumask var.
Why?
> The window for creation of cache is somewhat narrow: > - After last update of nr_cpu_ids(via set_nr_cpu_ids()) > - After kmem cache is available. > - Before any alloc_cpumask_var_node() invocations(sched_init() e.g).
OK, so this sounds somewhat fragile. It's maybe correct, but I fail to see what is gained by this, and the commit message does not provide any hints.
Rasmus
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