Messages in this thread | | | Date | Fri, 23 May 2014 13:39:57 -0400 | From | Tejun Heo <> | Subject | Re: [PATCH RFC] blkcg: prepare blkcg knobs for default hierarchy |
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Hello, Vivek.
On Wed, Apr 23, 2014 at 03:21:09PM -0400, Vivek Goyal wrote: > What about sync/async differentiation? Throttling layer seems to flag a request sync > only if bio->bi_rw flag has REQ_SYNC set. While CFQ seems to consider > request sync if bio is either read or bio->bi_rw has REQ_SYNC flag set.
Working on this again, AFAICS, both treat REQ_SYNC the same way as far as stats are concerned. If SYNC is set, it's sync; otherwise, it's accounted as async whether read or write.
Thanks.
-- tejun
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