[ofa-general] Re: [RFC] [PATCH 2/2] for 2.6.23: ib/sa - add local path record caching

[Michael S. Tsirkin]

It seems that below you try to get 0x7F paths to each dest:

+enum {
+	SA_DB_MAX_PATHS_PER_DEST = 0x7F,
+	SA_DB_MIN_RETRY_TIMER	 = 4000,  /*   4 sec */
+	SA_DB_MAX_RETRY_TIMER	 = 256000 /* 256 sec */
+};
+
+static int set_paths_per_dest(const char *val, struct kernel_param *kp);
+static unsigned long paths_per_dest = SA_DB_MAX_PATHS_PER_DEST;
+module_param_call(paths_per_dest, set_paths_per_dest, param_get_ulong,
+		  &paths_per_dest, 0644);
+MODULE_PARM_DESC(paths_per_dest, "Maximum number of paths to retrieve "
+				 "to each destination (DGID).  Set to 0 "
+				 "to disable cache.");

But here you seem to bypass cache for multi-path queries:

+int ib_sa_path_rec_get(struct ib_sa_client *client,
+		       struct ib_device *device, u8 port_num,
+		       struct ib_sa_path_rec *rec,
+		       ib_sa_comp_mask comp_mask,
+		       int timeout_ms, gfp_t gfp_mask,
+		       void (*callback)(int status,
+					struct ib_sa_path_rec *resp,
+					void *context),
+		       void *context,
+		       struct ib_sa_query **sa_query)
+{
+	struct sa_path_request *req;
+	struct ib_sa_attr_iter iter;
+	struct ib_sa_path_rec *path_rec;
+	int ret;
+
+	if (!paths_per_dest)
+		goto query_sa;
+
+	if (!(comp_mask & IB_SA_PATH_REC_DGID) ||
+	    !(comp_mask & IB_SA_PATH_REC_NUMB_PATH) || rec->numb_path != 1)
+		goto query_sa;

how are multiple paths used?

-- 
MST