Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: blk_mq_update_queue_map makes an (invalid?) assumption about cpu ordering | Date | Tue, 15 Oct 2013 14:25:00 -0400 |
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Jens Axboe <axboe@kernel.dk> writes:
>> This assumes that the first_sibling is listed before any other siblings, >> which I don't believe is true. I don't think you get any guaranteed >> ordering in that cpu_possible_mask. >> >> ... or did I miss something? > > That's correct, it's assuming the first sibling is the lowest numbered > one. Are there cases where that would not be correct? I was sort of > assuming that was what "first" meant here.
Yeah, you're right. I hadn't read down the call chain:
static int get_first_sibling(unsigned int cpu) ret = cpumask_first(topology_thread_cpumask(cpu));
Nothing to see here, move along...
-Jeff
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