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| author | Christoph Hellwig <hch@lst.de> | 2014-04-15 14:38:31 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-07-25 23:16:21 +0200 |
| commit | c53c6d6a68b13b1dff2892551b56cfdc07887d9e (patch) | |
| tree | 8bd6ddc1ff0f33e357ad6c230f62fd7b1cf1b28a /include | |
| parent | scsi: unwind blk_end_request_all and blk_end_request_err calls (diff) | |
| download | linux-c53c6d6a68b13b1dff2892551b56cfdc07887d9e.tar.xz linux-c53c6d6a68b13b1dff2892551b56cfdc07887d9e.zip | |
scatterlist: allow chaining to preallocated chunks
Blk-mq drivers usually preallocate their S/G list as part of the request,
but if we want to support the very large S/G lists currently supported by
the SCSI code that would tie up a lot of memory in the preallocated request
pool. Add support to the scatterlist code so that it can initialize a
S/G list that uses a preallocated first chunks and dynamically allocated
additional chunks. That way the scsi-mq code can preallocate a first
page worth of S/G entries as part of the request, and dynamically extend
the S/G list when needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/scatterlist.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index a964f7285600..f4ec8bbcb372 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -229,10 +229,10 @@ void sg_init_one(struct scatterlist *, const void *, unsigned int); typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t); typedef void (sg_free_fn)(struct scatterlist *, unsigned int); -void __sg_free_table(struct sg_table *, unsigned int, sg_free_fn *); +void __sg_free_table(struct sg_table *, unsigned int, bool, sg_free_fn *); void sg_free_table(struct sg_table *); -int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, gfp_t, - sg_alloc_fn *); +int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, + struct scatterlist *, gfp_t, sg_alloc_fn *); int sg_alloc_table(struct sg_table *, unsigned int, gfp_t); int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int n_pages, |