[PATCH 22/46] Staging: hv: storvsc: Optimize the bounce buffer handling in the "read" case

K. Y. Srinivasan
2011-08-27T18:11:30Z

Optimize the bounce buffer handling in the "read" case.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/storvsc_drv.c | 10 ++++------
1 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 90b91ad..3e00e70 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -560,12 +560,10 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
PAGE_SHIFT;

- /*
- * FIXME: We can optimize on reads by just skipping
- * this
- */
- copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
- scsi_sg_count(scmnd));
+ if (vm_srb->data_in == WRITE_TYPE)
+ copy_to_bounce_buffer(sgl,
+ cmd_request->bounce_sgl,
+ scsi_sg_count(scmnd));

sgl = cmd_request->bounce_sgl;
sg_count = cmd_request->bounce_sgl_count;
--
1.7.4.1