Re: [PATCH for-next v10 5/7] block: factor out bio_map_get helper

Anuj Gupta
2022-09-29T11:50:43Z

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On Wed, Sep 28, 2022 at 07:31:21PM +0200, Christoph Hellwig wrote:
> On Tue, Sep 27, 2022 at 11:06:08PM +0530, Kanchan Joshi wrote:
> > Move bio allocation logic from bio_map_user_iov to a new helper
> > bio_map_get. It is named so because functionality is opposite of what is
> > done inside bio_map_put. This is a prep patch.
>
> I'm still not a fan of using bio_sets for passthrough and would be
> much happier if we could drill down what the problems with the
> slab per-cpu allocator are, but it seems like I've lost that fight
> against Jens..
>
> > +static struct bio *bio_map_get(struct request *rq, unsigned int nr_vecs,
> > gfp_t gfp_mask)
>
> But these names just seems rather misleading. Why not someting
> like blk_rq_map_bio_alloc and blk_mq_map_bio_put?

Agreed, will rename the alloc and put function in the next iteration

>
> Not really new in this code but a question to Jens: The existing
> bio_map_user_iov has no real upper bounds on the number of bios
> allocated, how does that fit with the very limited pool size of
> fs_bio_set?

--
Anuj Gupta

>
>

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