[ofw][patch][ibal] fix ping disappear after restart of opensm

Leonid Keller leonid at mellanox.co.il
Wed May 27 04:02:54 PDT 2009


Summary: Ill-defined mechanism of event propagation
 
Bug description and reproduction:
 
1. Connect to machines (A and B) via IB switch
2. Run subnet manager (say, opensm) on B
3. Kill opensm and clear arp tables
4. Rerun opensm - ping will not longer work
5. That's because new opensm instance will clear old multicast groups,
and side A will be not aware about opensm restart and will not request
to join new MCAST group
 

Explanations:
 
There are 2 types of events relevant in our case: PnP and AE.
 
The problem had happened due to:
 
1. During opensm restart, port will generate AE event:
IB_EVENT_LID_CHANGE or (in other cases) IB_EVENT_CLIENT_REREGISTER
These events will be generated even in the case when SM was restarted,
but LID has not been not actually changed.
 

2. All PnP events were handled properly; but these events were mapped to
IB_AE_FATAL
This patch fixes it and maps IB_EVENT_* events to appropriate IB_AE_*
events and then to IB_PNP_* events
 

3. function force_smi_poll() will now update it's subscribers about LID
change event iff LID was changed.
So, we still have the problem when opensm was restarted and no one of
the port attributes was changed
This patch generated appropriate IB_PNP event to resolve this issue.
 
Signed off by: xalex (xalex at mellanox.co.il)
 
 
Index: core/al/al_ci_ca.h
===================================================================
--- core/al/al_ci_ca.h (revision 2195)
+++ core/al/al_ci_ca.h (working copy)
@@ -65,6 +65,11 @@
  IN  const ib_ca_handle_t    h_ca );
 #endif
 
+#define MAX_AE    32
+typedef struct _al_ae_info {
+ ib_pnp_event_t   pnp_event;
+ uint8_t     port_index;
+} al_ae_info_t;
 
 
 typedef struct _al_ci_ca
@@ -106,6 +111,12 @@
  /* "end of PnP handling" event */
  cl_event_t     event;
 
+ /* Array of pending AEs (Asynchronic events) */
+ al_ae_info_t    ae[MAX_AE];
+ int       ci;
+ int       pi;
+ atomic32_t     cnt;
+
 } al_ci_ca_t;
 
 
Index: core/al/al_ci_ca_shared.c
===================================================================
--- core/al/al_ci_ca_shared.c (revision 2195)
+++ core/al/al_ci_ca_shared.c (working copy)
@@ -250,6 +250,7 @@
  p_event_item = PARENT_STRUCT( p_item, event_item_t,
async_item.pool_item );
  p_event_item->event_rec.code = p_event_rec->code;
  p_event_item->event_rec.context = p_event_rec->context;
+ p_event_item->event_rec.port_number = p_event_rec->port_number;
 
  /* Queue the item on the asynchronous callback thread for processing.
*/
  p_event_item->async_item.pfn_callback = ci_ca_process_event_cb;
@@ -300,10 +301,27 @@
   cq_async_event_cb( &p_event_item->event_rec );
   break;
 
+#ifdef CL_KERNEL
+
+ case IB_AE_LID_CHANGE:
+ case IB_AE_CLIENT_REREGISTER:
+  // These AE events will be generated even in the case when
+  // SM was restaretd but LID will not actually change.
+  // It's important to propagate these event (via PnP mechanism)
+  // up to subscribers. Otherwise, there will be no ping after
+  // subnet manager restart
+  //if (AL_OBJ_IS_TYPE(p_obj, AL_OBJ_TYPE_CI_CA)
+  if (AL_BASE_TYPE( p_obj->type) == AL_OBJ_TYPE_CI_CA) {
+    pnp_force_event( (struct _al_ci_ca *) p_obj, IB_PNP_LID_CHANGE,
+     p_event_item->event_rec.port_number );
+  }
+  break;
+#endif //CL_KERNEL
+
  case IB_AE_PORT_TRAP:
  case IB_AE_PORT_DOWN:
  case IB_AE_PORT_ACTIVE:
- case IB_AE_CLIENT_REREGISTER:
+ 
 #ifdef CL_KERNEL
   /* The SMI polling routine may report a PnP event. */
   force_smi_poll();
Index: core/al/al_pnp.h
===================================================================
--- core/al/al_pnp.h (revision 2195)
+++ core/al/al_pnp.h (working copy)
@@ -216,6 +216,13 @@
  IN    KEVENT      *p_sync_event,
   OUT   ib_pnp_handle_t* const  ph_pnp );
 
+void
+pnp_force_event(
+ IN   struct _al_ci_ca  * p_ci_ca,
+ IN   ib_pnp_event_t pnp_event,
+ IN   uint8_t port_num);
+
+
 #endif /* CL_KERNEL */
 
 static inline ib_pnp_class_t
Index: core/al/kernel/al_ci_ca.c
===================================================================
--- core/al/kernel/al_ci_ca.c (revision 2195)
+++ core/al/kernel/al_ci_ca.c (working copy)
@@ -354,6 +354,7 @@
  event_rec.code = p_event_record->type;
  event_rec.context = p_event_record->context;
  event_rec.vendor_specific = p_event_record->vendor_specific;
+ event_rec.port_number = p_event_record->port_number;
 
  ci_ca_async_event( &event_rec );
 
Index: core/al/kernel/al_pnp.c
===================================================================
--- core/al/kernel/al_pnp.c (revision 2195)
+++ core/al/kernel/al_pnp.c (working copy)
@@ -605,6 +605,7 @@
  {
   AL_PRINT( TRACE_LEVEL_INFORMATION, AL_DBG_PNP,
    ("p_context is already in context map %I64x \n",p_context->guid));
+  cl_free( p_context );
   p_context = NULL;
  }
  
@@ -1490,6 +1491,24 @@
    __pnp_process_port_forward( &event_rec );
   }
  }
+
+ /* send asynchronous events */
+ {
+  int ci = p_ci_ca->ci;
+  int cnt = p_ci_ca->cnt % MAX_AE;
+
+  while ( cnt-- > 0 )
+  {
+    event_rec.pnp_event = p_ci_ca->ae[ci].pnp_event;
+    event_rec.port_index = p_ci_ca->ae[ci].port_index;
+    cl_atomic_dec( &p_ci_ca->cnt );
+    __pnp_process_port_forward( &event_rec );
+    if ( ++ci >= MAX_AE )
+     ci = 0;
+  }
+  p_ci_ca->ci = ci;
+ }
+
 }
 
 
@@ -1749,3 +1768,26 @@
  AL_EXIT( AL_DBG_PNP );
  return IB_UNSUPPORTED;
 }
+
+void
+pnp_force_event(
+ IN   struct _al_ci_ca  * p_ci_ca,
+ IN   ib_pnp_event_t pnp_event,
+ IN  uint8_t port_num)
+{
+ 
+#define PORT_INDEX_OFFSET 1
+
+ ASSERT(p_ci_ca);
+ 
+ if (!p_ci_ca)
+  return;
+ 
+ p_ci_ca->ae[p_ci_ca->pi].pnp_event = pnp_event;
+ p_ci_ca->ae[p_ci_ca->pi].port_index = port_num - PORT_INDEX_OFFSET;
+ cl_atomic_inc( &p_ci_ca->cnt );
+ if ( ++p_ci_ca->pi >= MAX_AE )
+  p_ci_ca->pi = 0;
+}
+
+
Index: inc/iba/ib_al.h
===================================================================
--- inc/iba/ib_al.h (revision 2195)
+++ inc/iba/ib_al.h (working copy)
@@ -473,6 +473,8 @@
   TO_LONG_PTR(struct _ib_srq*,   h_srq);
 
  } handle;
+ 
+ uint8_t          port_number;
 
 } ib_async_event_rec_t;
 /*

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