On 5/15/18 10:11 AM, Jens Axboe wrote: > On 5/15/18 10:00 AM, Matthew Wilcox wrote: >> From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> >> >> The sbitmap and the percpu_ida perform essentially the same task, >> allocating tags for commands. Since the sbitmap is more used than >> the percpu_ida, convert the percpu_ida users to the sbitmap API. > > It should also be the same performance as percpu_ida in light use, and > performs much better at > 50% utilization of the tag space. I think > that's better justification than "more used than". Had to search long and hard for the perf numbers I did for percpu_ida on higher utilization, but here it is: https://lkml.org/lkml/2014/4/22/553 -- Jens Axboe
