Messages in this thread | | | Date | Wed, 17 Aug 2022 12:44:09 +0300 | Subject | Re: [RFC PATCH] nvmet-tcp: Don't kmap() pages which can't come from HIGHMEM | From | Sagi Grimberg <> |
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>> Therefore, I have two questions: am I right about thinking that the pages >> mapped in nvmet_tcp_map_pdu_iovec() are allocated with GFP_KERNEL? > > I think you are correct.
It is correct. It is the same model for the linux scsi target, sunrpc etc.
>> If so, can anyone with more knowledge than mine please say if my changes make >> any sense? > > I think it does make sense. I like the code simplification, though this use > was't really paying the kmap penalty since, as you mentioned, this is never > highmem.
Yes, its the same code-path. Would be great if we still had an abstraction that would do the right thing regardless of highmem or not like kmap provides though.
> You should also remove the cmd's 'nr_mapped' field while you're at it, > otherwise you'll hit the WARN in nvmet_tcp_free_cmd_buffers().
Not remove nr_mapped because we use it to know the iovec entries, but we can just remove the WARN statement.
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