[PATCH 100/117] Staging: hv: storvsc: Optimize the bounce buffer handling in the "read" case

From: K. Y. Srinivasan
Date: Fri Jul 15 2011 - 13:34:46 EST


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

Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
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 e2294d5..6e4725f 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -563,12 +563,10 @@ 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

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