[IA64] kdump: Short path to freeze CPUs
Setting monarch_cpu = -1 to let slaves frozen might not work, because
there might be slaves being late, not entered the rendezvous yet.
Such slaves might be caught in while (monarch_cpu == -1) loop.
Use kdump_in_progress instead of monarch_cpus to break INIT rendezvous
and let all slaves enter DIE_INIT_SLAVE_LEAVE smoothly.
And monarch no longer need to manage rendezvous if once kdump_in_progress
is set, catch the monarch in DIE_INIT_MONARCH_ENTER then.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: kexec@lists.infradead.org
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index 0995fdc..6631a9d 100644
--- a/arch/ia64/kernel/crash.c
+++ b/arch/ia64/kernel/crash.c
@@ -127,14 +127,13 @@
* If an INIT is asserted here:
* - All receivers might be slaves, since some of cpus could already
* be frozen and INIT might be masked on monarch. In this case,
- * all slaves will park in while (monarch_cpu == -1) loop before
- * DIE_INIT_SLAVE_ENTER that for waiting monarch enters.
- * => TBD: freeze all slaves
+ * all slaves will be frozen soon since kdump_in_progress will let
+ * them into DIE_INIT_SLAVE_LEAVE.
* - One might be a monarch, but INIT rendezvous will fail since
* at least this cpu already have INIT masked so it never join
* to the rendezvous. In this case, all slaves and monarch will
- * be frozen after timeout of the INIT rendezvous.
- * => TBD: freeze them without waiting timeout
+ * be frozen soon with no wait since the INIT rendezvous is skipped
+ * by kdump_in_progress.
*/
kdump_smp_send_stop();
/* not all cpu response to IPI, send INIT to freeze them */
@@ -187,6 +186,7 @@
break;
/* fall through */
case DIE_INIT_SLAVE_LEAVE:
+ case DIE_INIT_MONARCH_ENTER:
case DIE_MCA_RENDZVOUS_LEAVE:
unw_init_running(kdump_cpu_freeze, NULL);
break;
@@ -217,7 +217,6 @@
if (kdump_on_init && (nd->sos->rv_rc != 1)) {
if (atomic_inc_return(&kdump_in_progress) != 1)
kdump_freeze_monarch = 1;
- *(nd->monarch_cpu) = -1;
}
break;
case DIE_INIT_MONARCH_LEAVE:
@@ -228,10 +227,8 @@
case DIE_MCA_MONARCH_LEAVE:
/* *(nd->data) indicate if MCA is recoverable */
if (kdump_on_fatal_mca && !(*(nd->data))) {
- if (atomic_inc_return(&kdump_in_progress) == 1) {
- *(nd->monarch_cpu) = -1;
+ if (atomic_inc_return(&kdump_in_progress) == 1)
machine_kdump_on_init();
- }
/* We got fatal MCA while kdump!? No way!! */
}
break;