On 13/08/2018 18:38, Emilio G. Cota wrote: > > Fix it by implementing the CPU list as an RCU QLIST. This requires > a little bit of extra work to insert CPUs at the tail of > the list and to iterate over the list in reverse order (see previous patch). > > One might be tempted to just insert new CPUs at the head of the list. > However, I think this might lead to hard-to-debug issues, since it is > possible that callers are assuming that CPUs are inserted at the tail > (just like spapr code did in the previous patch). So instead of auditing > all callers, this patch simply keeps the old behaviour.
Why not add an RCU_QSIMPLEQ, or even use an array since the quadratic behavior should not be an issue? The advantage of the array is that reverse iteration becomes trivial. Thanks, Paolo
