diff options
| author | Gioh Kim <gi-oh.kim@cloud.ionos.com> | 2020-12-10 13:18:25 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-12-17 00:56:03 +0300 |
| commit | 5a1328d0c3a757cdd8c65f4dfe0a02502a5810bc (patch) | |
| tree | 7e268b3e7359720ddd1e08adcd159df922661479 /drivers/block/rnbd/rnbd-clt.h | |
| parent | 512c781fd28cb401ee9f2843e32bf4640732c671 (diff) | |
| download | linux-5a1328d0c3a757cdd8c65f4dfe0a02502a5810bc.tar.xz | |
block/rnbd-clt: Dynamically allocate sglist for rnbd_iu
The BMAX_SEGMENT static array for scatterlist is embedded in
rnbd_iu structure to avoid memory allocation in hot IO path.
In many cases, we do need only several sg entries because many IOs
have only several segments.
This patch change rnbd_iu to check the number of segments in the request
and allocate sglist dynamically.
For io path, use sg_alloc_table_chained to allocate sg list faster.
First it makes two sg entries after pdu of request.
The sg_alloc_table_chained uses the pre-allocated sg entries
if the number of segments of the request is less than two.
So it reduces the number of memory allocation.
Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/rnbd/rnbd-clt.h')
| -rw-r--r-- | drivers/block/rnbd/rnbd-clt.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h index efd67ae286ca..537d499dad3b 100644 --- a/drivers/block/rnbd/rnbd-clt.h +++ b/drivers/block/rnbd/rnbd-clt.h @@ -44,6 +44,13 @@ struct rnbd_iu_comp { int errno; }; +#ifdef CONFIG_ARCH_NO_SG_CHAIN +#define RNBD_INLINE_SG_CNT 0 +#else +#define RNBD_INLINE_SG_CNT 2 +#endif +#define RNBD_RDMA_SGL_SIZE (sizeof(struct scatterlist) * RNBD_INLINE_SG_CNT) + struct rnbd_iu { union { struct request *rq; /* for block io */ @@ -56,11 +63,12 @@ struct rnbd_iu { /* use to send msg associated with a sess */ struct rnbd_clt_session *sess; }; - struct scatterlist sglist[BMAX_SEGMENTS]; + struct sg_table sgt; struct work_struct work; int errno; struct rnbd_iu_comp comp; atomic_t refcount; + struct scatterlist first_sgl[]; /* must be the last one */ }; struct rnbd_cpu_qlist { |