Author: mav
Date: Wed Oct 9 19:22:01 2013
New Revision: 256223
URL: http://svnweb.freebsd.org/changeset/base/256223
Log:
MFC r254058:
Remove droping topology mutex after iterating 100 periphs in CAMGETPASSTHRU.
That is not so slow and so often operation to handle unneeded otherwise
xsoftc.xpt_generation and respective locking complications.
Modified:
stable/9/sys/cam/cam_periph.c
stable/9/sys/cam/cam_xpt.c
stable/9/sys/cam/cam_xpt_periph.h
Directory Properties:
stable/9/sys/ (props changed)
Modified: stable/9/sys/cam/cam_periph.c
==============================================================================
--- stable/9/sys/cam/cam_periph.c Wed Oct 9 19:19:53 2013
(r256222)
+++ stable/9/sys/cam/cam_periph.c Wed Oct 9 19:22:01 2013
(r256223)
@@ -258,7 +258,7 @@ failure:
break;
case 3:
CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));
- xpt_remove_periph(periph, /*topology_lock_held*/ 0);
+ xpt_remove_periph(periph);
/* FALLTHROUGH */
case 2:
xpt_lock_buses();
@@ -645,7 +645,7 @@ camperiphfree(struct cam_periph *periph)
TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
(*p_drv)->generation++;
- xpt_remove_periph(periph, /*topology_lock_held*/ 1);
+ xpt_remove_periph(periph);
xpt_unlock_buses();
CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));
Modified: stable/9/sys/cam/cam_xpt.c
==============================================================================
--- stable/9/sys/cam/cam_xpt.c Wed Oct 9 19:19:53 2013 (r256222)
+++ stable/9/sys/cam/cam_xpt.c Wed Oct 9 19:22:01 2013 (r256223)
@@ -96,7 +96,6 @@ typedef enum {
struct xpt_softc {
xpt_flags flags;
- u_int32_t xpt_generation;
/* number of high powered commands that can go through right now */
STAILQ_HEAD(highpowerlist, cam_ed) highpowerq;
@@ -608,24 +607,11 @@ xptdoioctl(struct cdev *dev, u_long cmd,
struct periph_driver **p_drv;
char *name;
u_int unit;
- u_int cur_generation;
int base_periph_found;
- int splbreaknum;
ccb = (union ccb *)addr;
unit = ccb->cgdl.unit_number;
name = ccb->cgdl.periph_name;
- /*
- * Every 100 devices, we want to drop our lock protection to
- * give the software interrupt handler a chance to run.
- * Most systems won't run into this check, but this should
- * avoid starvation in the software interrupt handler in
- * large systems.
- */
- splbreaknum = 100;
-
- ccb = (union ccb *)addr;
-
base_periph_found = 0;
/*
@@ -639,8 +625,6 @@ xptdoioctl(struct cdev *dev, u_long cmd,
/* Keep the list from changing while we traverse it */
xpt_lock_buses();
-ptstartover:
- cur_generation = xsoftc.xpt_generation;
/* first find our driver in the list of drivers */
for (p_drv = periph_drivers; *p_drv != NULL; p_drv++)
@@ -667,15 +651,8 @@ ptstartover:
for (periph = TAILQ_FIRST(&(*p_drv)->units); periph != NULL;
periph = TAILQ_NEXT(periph, unit_links)) {
- if (periph->unit_number == unit) {
+ if (periph->unit_number == unit)
break;
- } else if (--splbreaknum == 0) {
- xpt_unlock_buses();
- xpt_lock_buses();
- splbreaknum = 100;
- if (cur_generation != xsoftc.xpt_generation)
- goto ptstartover;
- }
}
/*
* If we found the peripheral driver that the user passed
@@ -1015,15 +992,11 @@ xpt_add_periph(struct cam_periph *periph
SLIST_INSERT_HEAD(periph_head, periph, periph_links);
}
- xpt_lock_buses();
- xsoftc.xpt_generation++;
- xpt_unlock_buses();
-
return (status);
}
void
-xpt_remove_periph(struct cam_periph *periph, int topology_lock_held)
+xpt_remove_periph(struct cam_periph *periph)
{
struct cam_ed *device;
@@ -1043,14 +1016,6 @@ xpt_remove_periph(struct cam_periph *per
SLIST_REMOVE(periph_head, periph, cam_periph, periph_links);
}
-
- if (topology_lock_held == 0)
- xpt_lock_buses();
-
- xsoftc.xpt_generation++;
-
- if (topology_lock_held == 0)
- xpt_unlock_buses();
}
Modified: stable/9/sys/cam/cam_xpt_periph.h
==============================================================================
--- stable/9/sys/cam/cam_xpt_periph.h Wed Oct 9 19:19:53 2013
(r256222)
+++ stable/9/sys/cam/cam_xpt_periph.h Wed Oct 9 19:22:01 2013
(r256223)
@@ -42,8 +42,7 @@ void xpt_polled_action(union ccb *ccb);
void xpt_release_ccb(union ccb *released_ccb);
void xpt_schedule(struct cam_periph *perph, u_int32_t new_priority);
int32_t xpt_add_periph(struct cam_periph *periph);
-void xpt_remove_periph(struct cam_periph *periph,
- int topology_lock_held);
+void xpt_remove_periph(struct cam_periph *periph);
void xpt_announce_periph(struct cam_periph *periph,
char *announce_string);
void xpt_announce_quirks(struct cam_periph *periph,
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