[IA64-SGI] fixes for XPC disengage and open/close protocol
This patch addresses a few issues with the open/close protocol that
were revealed by the newly added disengage functionality combined
with more extensive testing.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index feece20..db349c6 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -91,6 +91,10 @@
static int xpc_hb_check_min_interval = 10;
static int xpc_hb_check_max_interval = 120;
+int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
+static int xpc_disengage_request_min_timelimit = 0;
+static int xpc_disengage_request_max_timelimit = 120;
+
static ctl_table xpc_sys_xpc_hb_dir[] = {
{
1,
@@ -129,6 +133,19 @@
0555,
xpc_sys_xpc_hb_dir
},
+ {
+ 2,
+ "disengage_request_timelimit",
+ &xpc_disengage_request_timelimit,
+ sizeof(int),
+ 0644,
+ NULL,
+ &proc_dointvec_minmax,
+ &sysctl_intvec,
+ NULL,
+ &xpc_disengage_request_min_timelimit,
+ &xpc_disengage_request_max_timelimit
+ },
{0}
};
static ctl_table xpc_sys_dir[] = {
@@ -153,11 +170,11 @@
static unsigned long xpc_hb_check_timeout;
-/* used as an indication of when the xpc_hb_checker thread is inactive */
-static DECLARE_MUTEX_LOCKED(xpc_hb_checker_inactive);
+/* notification that the xpc_hb_checker thread has exited */
+static DECLARE_MUTEX_LOCKED(xpc_hb_checker_exited);
-/* used as an indication of when the xpc_discovery thread is inactive */
-static DECLARE_MUTEX_LOCKED(xpc_discovery_inactive);
+/* notification that the xpc_discovery thread has exited */
+static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
static struct timer_list xpc_hb_timer;
@@ -181,7 +198,7 @@
struct xpc_partition *part = (struct xpc_partition *) data;
- DBUG_ON(XPC_TICKS < part->disengage_request_timeout);
+ DBUG_ON(jiffies < part->disengage_request_timeout);
(void) xpc_partition_disengaged(part);
@@ -292,8 +309,8 @@
dev_dbg(xpc_part, "heartbeat checker is exiting\n");
- /* mark this thread as inactive */
- up(&xpc_hb_checker_inactive);
+ /* mark this thread as having exited */
+ up(&xpc_hb_checker_exited);
return 0;
}
@@ -312,8 +329,8 @@
dev_dbg(xpc_part, "discovery thread is exiting\n");
- /* mark this thread as inactive */
- up(&xpc_discovery_inactive);
+ /* mark this thread as having exited */
+ up(&xpc_discovery_exited);
return 0;
}
@@ -703,6 +720,7 @@
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
int n_needed;
+ unsigned long irq_flags;
daemonize("xpc%02dc%d", partid, ch_number);
@@ -713,11 +731,14 @@
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
- DBUG_ON(!(ch->flags & XPC_C_CONNECTED));
/* let registerer know that connection has been established */
- if (atomic_read(&ch->kthreads_assigned) == 1) {
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ if (!(ch->flags & XPC_C_CONNECTCALLOUT)) {
+ ch->flags |= XPC_C_CONNECTCALLOUT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
xpc_connected_callout(ch);
/*
@@ -732,14 +753,23 @@
!(ch->flags & XPC_C_DISCONNECTING)) {
xpc_activate_kthreads(ch, n_needed);
}
+ } else {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
}
xpc_kthread_waitmsgs(part, ch);
}
if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
- if (ch->flags & XPC_C_CONNECTCALLOUT) {
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ if ((ch->flags & XPC_C_CONNECTCALLOUT) &&
+ !(ch->flags & XPC_C_DISCONNECTCALLOUT)) {
+ ch->flags |= XPC_C_DISCONNECTCALLOUT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
xpc_disconnecting_callout(ch);
+ } else {
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
}
if (atomic_dec_return(&part->nchannels_engaged) == 0) {
xpc_mark_partition_disengaged(part);
@@ -780,9 +810,29 @@
while (needed-- > 0) {
+
+ /*
+ * The following is done on behalf of the newly created
+ * kthread. That kthread is responsible for doing the
+ * counterpart to the following before it exits.
+ */
+ (void) xpc_part_ref(part);
+ xpc_msgqueue_ref(ch);
+ if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+ atomic_inc_return(&part->nchannels_engaged) == 1) {
+ xpc_mark_partition_engaged(part);
+ }
+
pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
if (pid < 0) {
/* the fork failed */
+ if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+ atomic_dec_return(&part->nchannels_engaged) == 0) {
+ xpc_mark_partition_disengaged(part);
+ xpc_IPI_send_disengage(part);
+ }
+ xpc_msgqueue_deref(ch);
+ xpc_part_deref(part);
if (atomic_read(&ch->kthreads_assigned) <
ch->kthreads_idle_limit) {
@@ -802,18 +852,6 @@
break;
}
- /*
- * The following is done on behalf of the newly created
- * kthread. That kthread is responsible for doing the
- * counterpart to the following before it exits.
- */
- (void) xpc_part_ref(part);
- xpc_msgqueue_ref(ch);
- if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
- if (atomic_inc_return(&part->nchannels_engaged) == 1) {
- xpc_mark_partition_engaged(part);
- }
- }
ch->kthreads_created++; // >>> temporary debug only!!!
}
}
@@ -826,26 +864,49 @@
partid_t partid;
struct xpc_partition *part;
struct xpc_channel *ch;
+ int wakeup_channel_mgr;
/* now wait for all callouts to the caller's function to cease */
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
- if (xpc_part_ref(part)) {
- ch = &part->channels[ch_number];
-
- if (ch->flags & XPC_C_WDISCONNECT) {
- if (!(ch->flags & XPC_C_DISCONNECTED)) {
- (void) down(&ch->wdisconnect_sema);
- }
- spin_lock_irqsave(&ch->lock, irq_flags);
- ch->flags &= ~XPC_C_WDISCONNECT;
- spin_unlock_irqrestore(&ch->lock, irq_flags);
- }
-
- xpc_part_deref(part);
+ if (!xpc_part_ref(part)) {
+ continue;
}
+
+ ch = &part->channels[ch_number];
+
+ if (!(ch->flags & XPC_C_WDISCONNECT)) {
+ xpc_part_deref(part);
+ continue;
+ }
+
+ (void) down(&ch->wdisconnect_sema);
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
+ wakeup_channel_mgr = 0;
+
+ if (ch->delayed_IPI_flags) {
+ if (part->act_state != XPC_P_DEACTIVATING) {
+ spin_lock(&part->IPI_lock);
+ XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+ ch->number, ch->delayed_IPI_flags);
+ spin_unlock(&part->IPI_lock);
+ wakeup_channel_mgr = 1;
+ }
+ ch->delayed_IPI_flags = 0;
+ }
+
+ ch->flags &= ~XPC_C_WDISCONNECT;
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+ if (wakeup_channel_mgr) {
+ xpc_wakeup_channel_mgr(part);
+ }
+
+ xpc_part_deref(part);
}
}
@@ -873,11 +934,11 @@
/* ignore all incoming interrupts */
free_irq(SGI_XPC_ACTIVATE, NULL);
- /* wait for the discovery thread to mark itself inactive */
- down(&xpc_discovery_inactive);
+ /* wait for the discovery thread to exit */
+ down(&xpc_discovery_exited);
- /* wait for the heartbeat checker thread to mark itself inactive */
- down(&xpc_hb_checker_inactive);
+ /* wait for the heartbeat checker thread to exit */
+ down(&xpc_hb_checker_exited);
/* sleep for a 1/3 of a second or so */
@@ -893,6 +954,7 @@
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
+
if (xpc_partition_disengaged(part) &&
part->act_state == XPC_P_INACTIVE) {
continue;
@@ -930,7 +992,7 @@
/* now it's time to eliminate our heartbeat */
del_timer_sync(&xpc_hb_timer);
- DBUG_ON(xpc_vars->heartbeating_to_mask == 0);
+ DBUG_ON(xpc_vars->heartbeating_to_mask != 0);
/* take ourselves off of the reboot_notifier_list */
(void) unregister_reboot_notifier(&xpc_reboot_notifier);
@@ -1134,7 +1196,7 @@
dev_err(xpc_part, "failed while forking discovery thread\n");
/* mark this new thread as a non-starter */
- up(&xpc_discovery_inactive);
+ up(&xpc_discovery_exited);
xpc_do_exit(xpcUnloading);
return -EBUSY;
@@ -1172,3 +1234,7 @@
MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
"heartbeat checks.");
+module_param(xpc_disengage_request_timelimit, int, 0);
+MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
+ "for disengage request to complete.");
+