Messages in this thread | | | Date | Wed, 14 Jan 2015 00:36:48 +0100 | From | Richard Weinberger <> | Subject | Re: [PATCH 2/2 v2] UBI: Block: Add blk-mq support |
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Am 14.01.2015 um 00:30 schrieb Jens Axboe: >> If I understand you correctly it can happen that blk_rq_bytes() returns >> more bytes than blk_rq_map_sg() allocated, right? > > No, the number of bytes will be the same, no magic is involved :-)
Good to know. :)
> But lets say the initial request has 4 bios, with each 2 pages, for a > total of 8 segments. Lets further assume that the pages in each bio are > contiguous, so that blk_rq_map_sg() will map this to 4 sg elements, each > 2xpages long. > > Now, this may already be handled just fine, and you don't need to > update/store the actual sg count. I just looked at the source, and I'm > assuming it'll do the right thing (ubi_read_sg() will bump the active sg > element, when that size has been consumed), but I don't have > ubi_read_sg() in my tree to verify.
Currently the sg count is hard coded to UBI_MAX_SG_COUNT.
I'm sorry, I forgot to CC you and hch to this patch: https://lkml.org/lkml/2015/1/10/204
Thanks, //richard
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