Hi Ming On 09/11/2018 12:03 PM, Ming Lei wrote: > After the refcount is switched to atomic mode, the whole counting is > done on the atomic part. Then if the refcount need to switch to percpu mode > again, all percpu part of the counter is re-initialized as zero simply. This > is invariant with/without this patch. Does the "whole counting" here means ? (long)(sum (every cpu's refcounter)) + atomic refcounter and when switch to atomic mode, there could be value left in atomic refcounter. then the unsigned long percpu refcounter cound be decreased from 0. >From another angle, one request could be ended on a different cpu from the one where it is issued. Thanks Jianchao
