| Message ID | 542E8EAB.5010603@ce.jp.nec.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
On Fri, Oct 03 2014 at 7:55am -0400, Junichi Nomura <j-nomura@ce.jp.nec.com> wrote: > Users of bio_clone_fast() do not need its own bvecs. > Allocating bvec mempool for such users is waste of memory. > > This variant allows them to create bioset without bvec mempool. > > Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> > --- > block/bio.c | 61 ++++++++++++++++++++++++++++++++++++++--------------- > include/linux/bio.h | 1 + > 2 files changed, 45 insertions(+), 17 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index 3e6331d..98c5100 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -1900,20 +1903,9 @@ void bioset_free(struct bio_set *bs) > } > EXPORT_SYMBOL(bioset_free); > > -/** > - * bioset_create - Create a bio_set > - * @pool_size: Number of bio and bio_vecs to cache in the mempool > - * @front_pad: Number of bytes to allocate in front of the returned bio > - * > - * Description: > - * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller > - * to ask for a number of bytes to be allocated in front of the bio. > - * Front pad allocation is useful for embedding the bio inside > - * another structure, to avoid allocating extra data to go with the bio. > - * Note that the bio must be embedded at the END of that structure always, > - * or things will break badly. > - */ > -struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) > +static struct bio_set *__bioset_create(unsigned int pool_size, > + unsigned int front_pad, > + unsigned int create_bvec_pool) > { > unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); > struct bio_set *bs; Any reason not to use bool for create_bvec_pool? > @@ -1951,8 +1945,41 @@ bad: > bioset_free(bs); > return NULL; > } > + > +/** > + * bioset_create - Create a bio_set > + * @pool_size: Number of bio and bio_vecs to cache in the mempool > + * @front_pad: Number of bytes to allocate in front of the returned bio > + * > + * Description: > + * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller > + * to ask for a number of bytes to be allocated in front of the bio. > + * Front pad allocation is useful for embedding the bio inside > + * another structure, to avoid allocating extra data to go with the bio. > + * Note that the bio must be embedded at the END of that structure always, > + * or things will break badly. > + */ > +struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) > +{ > + return __bioset_create(pool_size, front_pad, 1); > +} > EXPORT_SYMBOL(bioset_create); > > +/** > + * bioset_nobvec_create - Create a bio_set without bio_vec mempool > + * @pool_size: Number of bio to cache in the mempool > + * @front_pad: Number of bytes to allocate in front of the returned bio > + * > + * Description: > + * Same functionality as bioset_create() except that mempool is not > + * created for bio_vecs. Saving some memory for bio_clone_fast() users. > + */ > +struct bio_set *bioset_nobvec_create(unsigned int pool_size, unsigned int front_pad) > +{ > + return __bioset_create(pool_size, front_pad, 0); > +} > +EXPORT_SYMBOL(bioset_nobvec_create); > + > #ifdef CONFIG_BLK_CGROUP > /** > * bio_associate_current - associate a bio with %current And use true and false accordingly... > diff --git a/include/linux/bio.h b/include/linux/bio.h > index b39e500..7d7b2a7 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -342,6 +342,7 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors, > } > > extern struct bio_set *bioset_create(unsigned int, unsigned int); > +extern struct bio_set *bioset_nobvec_create(unsigned int, unsigned int); > extern void bioset_free(struct bio_set *); > extern mempool_t *biovec_create_pool(int pool_entries); Also, I prefer the function name: bioset_create_nobvec (to keep it in the "bioset_create" family). Otherwise, please feel free to add to v2: Acked-by: Mike Snitzer <snitzer@redhat.com> -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/block/bio.c b/block/bio.c index 3e6331d..98c5100 100644 --- a/block/bio.c +++ b/block/bio.c @@ -428,6 +428,9 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) front_pad = 0; inline_vecs = nr_iovecs; } else { + /* should not use nobvec bioset for nr_iovecs > 0 */ + if (WARN_ON_ONCE(!bs->bvec_pool && nr_iovecs > 0)) + return NULL; /* * generic_make_request() converts recursion to iteration; this * means if we're running beneath it, any bios we allocate and @@ -1900,20 +1903,9 @@ void bioset_free(struct bio_set *bs) } EXPORT_SYMBOL(bioset_free); -/** - * bioset_create - Create a bio_set - * @pool_size: Number of bio and bio_vecs to cache in the mempool - * @front_pad: Number of bytes to allocate in front of the returned bio - * - * Description: - * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller - * to ask for a number of bytes to be allocated in front of the bio. - * Front pad allocation is useful for embedding the bio inside - * another structure, to avoid allocating extra data to go with the bio. - * Note that the bio must be embedded at the END of that structure always, - * or things will break badly. - */ -struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) +static struct bio_set *__bioset_create(unsigned int pool_size, + unsigned int front_pad, + unsigned int create_bvec_pool) { unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); struct bio_set *bs; @@ -1938,9 +1930,11 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) if (!bs->bio_pool) goto bad; - bs->bvec_pool = biovec_create_pool(pool_size); - if (!bs->bvec_pool) - goto bad; + if (create_bvec_pool) { + bs->bvec_pool = biovec_create_pool(pool_size); + if (!bs->bvec_pool) + goto bad; + } bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); if (!bs->rescue_workqueue) @@ -1951,8 +1945,41 @@ bad: bioset_free(bs); return NULL; } + +/** + * bioset_create - Create a bio_set + * @pool_size: Number of bio and bio_vecs to cache in the mempool + * @front_pad: Number of bytes to allocate in front of the returned bio + * + * Description: + * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller + * to ask for a number of bytes to be allocated in front of the bio. + * Front pad allocation is useful for embedding the bio inside + * another structure, to avoid allocating extra data to go with the bio. + * Note that the bio must be embedded at the END of that structure always, + * or things will break badly. + */ +struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) +{ + return __bioset_create(pool_size, front_pad, 1); +} EXPORT_SYMBOL(bioset_create); +/** + * bioset_nobvec_create - Create a bio_set without bio_vec mempool + * @pool_size: Number of bio to cache in the mempool + * @front_pad: Number of bytes to allocate in front of the returned bio + * + * Description: + * Same functionality as bioset_create() except that mempool is not + * created for bio_vecs. Saving some memory for bio_clone_fast() users. + */ +struct bio_set *bioset_nobvec_create(unsigned int pool_size, unsigned int front_pad) +{ + return __bioset_create(pool_size, front_pad, 0); +} +EXPORT_SYMBOL(bioset_nobvec_create); + #ifdef CONFIG_BLK_CGROUP /** * bio_associate_current - associate a bio with %current diff --git a/include/linux/bio.h b/include/linux/bio.h index b39e500..7d7b2a7 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -342,6 +342,7 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors, } extern struct bio_set *bioset_create(unsigned int, unsigned int); +extern struct bio_set *bioset_nobvec_create(unsigned int, unsigned int); extern void bioset_free(struct bio_set *); extern mempool_t *biovec_create_pool(int pool_entries);
Users of bio_clone_fast() do not need its own bvecs. Allocating bvec mempool for such users is waste of memory. This variant allows them to create bioset without bvec mempool. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> --- block/bio.c | 61 ++++++++++++++++++++++++++++++++++++++--------------- include/linux/bio.h | 1 + 2 files changed, 45 insertions(+), 17 deletions(-)