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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/qla4xxx
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/qla4xxx')
-rw-r--r--drivers/scsi/qla4xxx/ql4_os.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index f4cd846..0d48fb4 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -79,8 +79,7 @@ static enum blk_eh_timer_return qla4xxx_eh_cmd_timed_out(struct scsi_cmnd *sc);
/*
* SCSI host template entry points
*/
-static int qla4xxx_queuecommand(struct scsi_cmnd *cmd,
- void (*done) (struct scsi_cmnd *));
+static int qla4xxx_queuecommand(struct Scsi_Host *h, struct scsi_cmnd *cmd);
static int qla4xxx_eh_abort(struct scsi_cmnd *cmd);
static int qla4xxx_eh_device_reset(struct scsi_cmnd *cmd);
static int qla4xxx_eh_target_reset(struct scsi_cmnd *cmd);
@@ -464,7 +463,7 @@ void qla4xxx_srb_compl(struct kref *ref)
* completion handling). Unfortunely, it sometimes calls the scheduler
* in interrupt context which is a big NO! NO!.
**/
-static int qla4xxx_queuecommand(struct scsi_cmnd *cmd,
+static int qla4xxx_queuecommand_lck(struct scsi_cmnd *cmd,
void (*done)(struct scsi_cmnd *))
{
struct scsi_qla_host *ha = to_qla_host(cmd->device->host);
@@ -538,6 +537,8 @@ qc_fail_command:
return 0;
}
+static DEF_SCSI_QCMD(qla4xxx_queuecommand)
+
/**
* qla4xxx_mem_free - frees memory allocated to adapter
* @ha: Pointer to host adapter structure.
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