summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/fd_mcs.c
diff options
context:
space:
mode:
authorJeff Garzik <jeff@garzik.org>2010-11-16 02:10:29 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-11-16 13:33:23 -0800
commitf281233d3eba15fb225d21ae2e228fd4553d824a (patch)
tree51134454ba8acb558735f90be5540f7d756483e3 /drivers/scsi/fd_mcs.c
parentbdbd01ac444bffb3c9aefed3059d12554059b320 (diff)
downloadop-kernel-dev-f281233d3eba15fb225d21ae2e228fd4553d824a.zip
op-kernel-dev-f281233d3eba15fb225d21ae2e228fd4553d824a.tar.gz
SCSI host lock push-down
Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Acked-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/scsi/fd_mcs.c')
-rw-r--r--drivers/scsi/fd_mcs.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/fd_mcs.c b/drivers/scsi/fd_mcs.c
index 2ad95aa..a2c6135 100644
--- a/drivers/scsi/fd_mcs.c
+++ b/drivers/scsi/fd_mcs.c
@@ -1072,7 +1072,7 @@ static int fd_mcs_release(struct Scsi_Host *shpnt)
return 0;
}
-static int fd_mcs_queue(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
+static int fd_mcs_queue_lck(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
{
struct Scsi_Host *shpnt = SCpnt->device->host;
@@ -1122,6 +1122,8 @@ static int fd_mcs_queue(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
return 0;
}
+static DEF_SCSI_QCMD(fd_mcs_queue)
+
#if DEBUG_ABORT || DEBUG_RESET
static void fd_mcs_print_info(Scsi_Cmnd * SCpnt)
{
OpenPOWER on IntegriCloud