On 4/21/22 12:57 PM, Pavel Begunkov wrote: > On 4/21/22 19:49, Stefan Roesch wrote: >> On 4/21/22 11:42 AM, Pavel Begunkov wrote: >>> On 4/20/22 23:51, Jens Axboe wrote: >>>> On Wed, 20 Apr 2022 12:14:39 -0700, Stefan Roesch wrote: >>>>> This adds the large CQE support for io-uring. Large CQE's are 16 bytes longer. >>>>> To support the longer CQE's the allocation part is changed and when the CQE is >>>>> accessed. >>>>> >>>>> The allocation of the large CQE's is twice as big, so the allocation size is >>>>> doubled. The ring size calculation needs to take this into account. >>> >>> I'm missing something here, do we have a user for it apart >>> from no-op requests? >>> >> >> Pavel, what started this work is the patch series "io_uring passthru over nvme" from samsung. >> (https://lore.kernel.org/io-uring/20220308152105.309618-1-joshi.k@xxxxxxxxxxx/) >> >> They will use the large SQE and CQE support. > > I see, thanks for clarifying. I saw it used in passthrough > patches, but it only got me more confused why it's applied > aforehand separately from the io_uring-cmd and passthrough It's just applied to a branch so the passthrough folks have something to base on, io_uring-big-sqe. It's not queued for 5.19 or anything like that yet. -- Jens Axboe
