Messages in this thread | | | Date | Fri, 20 Nov 2020 01:20:17 +0000 | From | Matthew Wilcox <> | Subject | Re: [PATCH v2 1/2] iov_iter: optimise iov_iter_npages for bvec |
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On Thu, Nov 19, 2020 at 11:24:38PM +0000, Pavel Begunkov wrote: > The block layer spends quite a while in iov_iter_npages(), but for the > bvec case the number of pages is already known and stored in > iter->nr_segs, so it can be returned immediately as an optimisation
Er ... no, it doesn't. nr_segs is the number of bvecs. Each bvec can store up to 4GB of contiguous physical memory.
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