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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-05-29 11:24:28 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-05-29 11:24:28 -0700 |
commit | 6e49ba1bb1deddd2da806284a37e7f3d3d711301 (patch) | |
tree | aa707aa3140bd7dc1853051c1c1a7bd9d280ebd4 /lib | |
parent | d0af69886656a93a8c4e9b5bb8f1894a50cf2d8a (diff) | |
parent | f36963c9d3f6f415732710da3acdd8608a9fa0e5 (diff) | |
download | lwn-6e49ba1bb1deddd2da806284a37e7f3d3d711301.tar.gz lwn-6e49ba1bb1deddd2da806284a37e7f3d3d711301.zip |
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull fixes for cpumask and modules from Rusty Russell:
"** NOW WITH TESTING! **
Two fixes which got lost in my recent distraction. One is a weird
cpumask function which needed to be rewritten, the other is a module
bug which is cc:stable"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
cpumask_set_cpu_local_first => cpumask_local_spread, lament
module: Call module notifier on failure after complete_formation()
Diffstat (limited to 'lib')
-rw-r--r-- | lib/cpumask.c | 74 |
1 files changed, 26 insertions, 48 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c index 830dd5dec40f..5f627084f2e9 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -139,64 +139,42 @@ void __init free_bootmem_cpumask_var(cpumask_var_t mask) #endif /** - * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first - * + * cpumask_local_spread - select the i'th cpu with local numa cpu's first * @i: index number - * @numa_node: local numa_node - * @dstp: cpumask with the relevant cpu bit set according to the policy + * @node: local numa_node * - * This function sets the cpumask according to a numa aware policy. - * cpumask could be used as an affinity hint for the IRQ related to a - * queue. When the policy is to spread queues across cores - local cores - * first. + * This function selects an online CPU according to a numa aware policy; + * local cpus are returned first, followed by non-local ones, then it + * wraps around. * - * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set - * the cpu bit and need to re-call the function. + * It's not very efficient, but useful for setup. */ -int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp) +unsigned int cpumask_local_spread(unsigned int i, int node) { - cpumask_var_t mask; int cpu; - int ret = 0; - - if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) - return -ENOMEM; + /* Wrap: we always want a cpu. */ i %= num_online_cpus(); - if (numa_node == -1 || !cpumask_of_node(numa_node)) { - /* Use all online cpu's for non numa aware system */ - cpumask_copy(mask, cpu_online_mask); + if (node == -1) { + for_each_cpu(cpu, cpu_online_mask) + if (i-- == 0) + return cpu; } else { - int n; - - cpumask_and(mask, - cpumask_of_node(numa_node), cpu_online_mask); - - n = cpumask_weight(mask); - if (i >= n) { - i -= n; - - /* If index > number of local cpu's, mask out local - * cpu's - */ - cpumask_andnot(mask, cpu_online_mask, mask); + /* NUMA first. */ + for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) + if (i-- == 0) + return cpu; + + for_each_cpu(cpu, cpu_online_mask) { + /* Skip NUMA nodes, done above. */ + if (cpumask_test_cpu(cpu, cpumask_of_node(node))) + continue; + + if (i-- == 0) + return cpu; } } - - for_each_cpu(cpu, mask) { - if (--i < 0) - goto out; - } - - ret = -EAGAIN; - -out: - free_cpumask_var(mask); - - if (!ret) - cpumask_set_cpu(cpu, dstp); - - return ret; + BUG(); } -EXPORT_SYMBOL(cpumask_set_cpu_local_first); +EXPORT_SYMBOL(cpumask_local_spread); |