| Message ID | 1383608187-27368-7-git-send-email-kmo@daterainc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 04, 2013 at 03:36:24PM -0800, Kent Overstreet wrote: > We get a measurable performance increase by handling this in the driver when > we're already looping over the biovec, instead of handling it separately in > generic_make_request() (or bio_add_page() originally) > > Signed-off-by: Kent Overstreet <kmo@daterainc.com> > --- > drivers/block/mtip32xx/mtip32xx.c | 46 +++++++++++++-------------------------- > 1 file changed, 15 insertions(+), 31 deletions(-) > > diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c > index d4c669b..c5a7a96 100644 > --- a/drivers/block/mtip32xx/mtip32xx.c > +++ b/drivers/block/mtip32xx/mtip32xx.c > @@ -2648,24 +2648,6 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector, > } > > /* > - * Release a command slot. > - * > - * @dd Pointer to the driver data structure. > - * @tag Slot tag > - * > - * return value > - * None > - */ > -static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag, > - int unaligned) > -{ > - struct semaphore *sem = unaligned ? &dd->port->cmd_slot_unal : > - &dd->port->cmd_slot; > - release_slot(dd->port, tag); > - up(sem); > -} > - > -/* > * Obtain a command slot and return its associated scatter list. > * > * @dd Pointer to the driver data structure. > @@ -4016,21 +3998,22 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio) > > sg = mtip_hw_get_scatterlist(dd, &tag, unaligned); > if (likely(sg != NULL)) { > - if (unlikely((bio)->bi_vcnt > MTIP_MAX_SG)) { > - dev_warn(&dd->pdev->dev, > - "Maximum number of SGL entries exceeded\n"); > - bio_io_error(bio); > - mtip_hw_release_scatterlist(dd, tag, unaligned); > - return; > - } > - > /* Create the scatter list for this bio. */ > bio_for_each_segment(bvec, bio, iter) { > - sg_set_page(&sg[nents], > - bvec.bv_page, > - bvec.bv_len, > - bvec.bv_offset); > - nents++; > + if (unlikely(nents == MTIP_MAX_SG)) { > + struct bio *split = bio_clone(bio, GFP_NOIO); > + Need to check for memory allocation failure here. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index d4c669b..c5a7a96 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -2648,24 +2648,6 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector, } /* - * Release a command slot. - * - * @dd Pointer to the driver data structure. - * @tag Slot tag - * - * return value - * None - */ -static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag, - int unaligned) -{ - struct semaphore *sem = unaligned ? &dd->port->cmd_slot_unal : - &dd->port->cmd_slot; - release_slot(dd->port, tag); - up(sem); -} - -/* * Obtain a command slot and return its associated scatter list. * * @dd Pointer to the driver data structure. @@ -4016,21 +3998,22 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio) sg = mtip_hw_get_scatterlist(dd, &tag, unaligned); if (likely(sg != NULL)) { - if (unlikely((bio)->bi_vcnt > MTIP_MAX_SG)) { - dev_warn(&dd->pdev->dev, - "Maximum number of SGL entries exceeded\n"); - bio_io_error(bio); - mtip_hw_release_scatterlist(dd, tag, unaligned); - return; - } - /* Create the scatter list for this bio. */ bio_for_each_segment(bvec, bio, iter) { - sg_set_page(&sg[nents], - bvec.bv_page, - bvec.bv_len, - bvec.bv_offset); - nents++; + if (unlikely(nents == MTIP_MAX_SG)) { + struct bio *split = bio_clone(bio, GFP_NOIO); + + split->bi_iter = iter; + bio->bi_iter.bi_size -= iter.bi_size; + bio_chain(split, bio); + generic_make_request(split); + break; + } + + sg_set_page(&sg[nents++], + bvec.bv_page, + bvec.bv_len, + bvec.bv_offset); } /* Issue the read/write. */ @@ -4145,6 +4128,7 @@ skip_create_disk: blk_queue_max_hw_sectors(dd->queue, 0xffff); blk_queue_max_segment_size(dd->queue, 0x400000); blk_queue_io_min(dd->queue, 4096); + set_bit(QUEUE_FLAG_LARGEBIOS, &dd->queue->queue_flags); /* * write back cache is not supported in the device. FUA depends on
We get a measurable performance increase by handling this in the driver when we're already looping over the biovec, instead of handling it separately in generic_make_request() (or bio_add_page() originally) Signed-off-by: Kent Overstreet <kmo@daterainc.com> --- drivers/block/mtip32xx/mtip32xx.c | 46 +++++++++++++-------------------------- 1 file changed, 15 insertions(+), 31 deletions(-)