aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/megaraid.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 16:33:23 -0500
commitf281233d3eba15fb225d21ae2e228fd4553d824a (patch)
tree51134454ba8acb558735f90be5540f7d756483e3 /drivers/scsi/megaraid.c
parentbdbd01ac444bffb3c9aefed3059d12554059b320 (diff)
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/megaraid.c')
-rw-r--r--drivers/scsi/megaraid.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index 7ceb5cf12c6b..9aa048525eb2 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -366,7 +366,7 @@ mega_runpendq(adapter_t *adapter)
366 * The command queuing entry point for the mid-layer. 366 * The command queuing entry point for the mid-layer.
367 */ 367 */
368static int 368static int
369megaraid_queue(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *)) 369megaraid_queue_lck(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *))
370{ 370{
371 adapter_t *adapter; 371 adapter_t *adapter;
372 scb_t *scb; 372 scb_t *scb;
@@ -409,6 +409,8 @@ megaraid_queue(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *))
409 return busy; 409 return busy;
410} 410}
411 411
412static DEF_SCSI_QCMD(megaraid_queue)
413
412/** 414/**
413 * mega_allocate_scb() 415 * mega_allocate_scb()
414 * @adapter - pointer to our soft state 416 * @adapter - pointer to our soft state
@@ -4456,7 +4458,7 @@ mega_internal_command(adapter_t *adapter, megacmd_t *mc, mega_passthru *pthru)
4456 4458
4457 scb->idx = CMDID_INT_CMDS; 4459 scb->idx = CMDID_INT_CMDS;
4458 4460
4459 megaraid_queue(scmd, mega_internal_done); 4461 megaraid_queue_lck(scmd, mega_internal_done);
4460 4462
4461 wait_for_completion(&adapter->int_waitq); 4463 wait_for_completion(&adapter->int_waitq);
4462 4464