Author: mav
Date: Sun Sep 6 18:40:48 2009
New Revision: 196897
URL: http://svn.freebsd.org/changeset/base/196897
Log:
Avoid extra swi_sched() call, if this SIM is already queued.
It reduces overhead for coalesced command completions.
Modified:
head/sys/cam/cam_xpt.c
Modified: head/sys/cam/cam_xpt.c
==============================================================================
--- head/sys/cam/cam_xpt.c Sun Sep 6 18:09:25 2009 (r196896)
+++ head/sys/cam/cam_xpt.c Sun Sep 6 18:40:48 2009 (r196897)
@@ -4198,12 +4198,12 @@ xpt_done(union ccb *done_ccb)
mtx_lock(&cam_simq_lock);
TAILQ_INSERT_TAIL(&cam_simq, sim,
links);
- sim->flags |= CAM_SIM_ON_DONEQ;
mtx_unlock(&cam_simq_lock);
+ sim->flags |= CAM_SIM_ON_DONEQ;
+ if ((done_ccb->ccb_h.path->periph->flags &
+ CAM_PERIPH_POLLED) == 0)
+ swi_sched(cambio_ih, 0);
}
- if ((done_ccb->ccb_h.path->periph->flags &
- CAM_PERIPH_POLLED) == 0)
- swi_sched(cambio_ih, 0);
break;
default:
panic("unknown periph type %d",
@@ -4889,16 +4889,20 @@ camisr(void *dummy)
mtx_lock(&cam_simq_lock);
TAILQ_INIT(&queue);
- TAILQ_CONCAT(&queue, &cam_simq, links);
- mtx_unlock(&cam_simq_lock);
-
- while ((sim = TAILQ_FIRST(&queue)) != NULL) {
- TAILQ_REMOVE(&queue, sim, links);
- CAM_SIM_LOCK(sim);
- sim->flags &= ~CAM_SIM_ON_DONEQ;
- camisr_runqueue(&sim->sim_doneq);
- CAM_SIM_UNLOCK(sim);
+ while (!TAILQ_EMPTY(&cam_simq)) {
+ TAILQ_CONCAT(&queue, &cam_simq, links);
+ mtx_unlock(&cam_simq_lock);
+
+ while ((sim = TAILQ_FIRST(&queue)) != NULL) {
+ TAILQ_REMOVE(&queue, sim, links);
+ CAM_SIM_LOCK(sim);
+ sim->flags &= ~CAM_SIM_ON_DONEQ;
+ camisr_runqueue(&sim->sim_doneq);
+ CAM_SIM_UNLOCK(sim);
+ }
+ mtx_lock(&cam_simq_lock);
}
+ mtx_unlock(&cam_simq_lock);
}
static void
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