[SCSI] zfcp: Track fabric and channel latencies provided by FCP adapter
Add the infrastructure to retrieve the fabric and channel latencies
from FSF commands for each SCSI command that has been processed. For
each unit, the sum, min, max and number of requests is tracked.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 8c7e2b7..d23027a 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -847,6 +847,14 @@
/* mark unit unusable as long as sysfs registration is not complete */
atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
+ spin_lock_init(&unit->latencies.lock);
+ unit->latencies.write.channel.min = 0xFFFFFFFF;
+ unit->latencies.write.fabric.min = 0xFFFFFFFF;
+ unit->latencies.read.channel.min = 0xFFFFFFFF;
+ unit->latencies.read.fabric.min = 0xFFFFFFFF;
+ unit->latencies.cmd.channel.min = 0xFFFFFFFF;
+ unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
+
if (device_register(&unit->sysfs_device)) {
kfree(unit);
return NULL;
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index bda8c77..306fcd0 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -708,6 +708,24 @@
struct timer_list timer;
};
+struct fsf_latency_record {
+ u32 min;
+ u32 max;
+ u64 sum;
+};
+
+struct latency_cont {
+ struct fsf_latency_record channel;
+ struct fsf_latency_record fabric;
+ u64 counter;
+};
+
+struct zfcp_latencies {
+ struct latency_cont read;
+ struct latency_cont write;
+ struct latency_cont cmd;
+ spinlock_t lock;
+};
struct zfcp_adapter {
struct list_head list; /* list of adapters */
@@ -723,6 +741,7 @@
u32 adapter_features; /* FCP channel features */
u32 connection_features; /* host connection features */
u32 hardware_version; /* of FCP channel */
+ u16 timer_ticks; /* time int for a tick */
struct Scsi_Host *scsi_host; /* Pointer to mid-layer */
struct list_head port_list_head; /* remote port list */
struct list_head port_remove_lh; /* head of ports to be
@@ -822,6 +841,7 @@
struct scsi_device *device; /* scsi device struct pointer */
struct zfcp_erp_action erp_action; /* pending error recovery */
atomic_t erp_counter;
+ struct zfcp_latencies latencies;
};
/* FSF request */
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index b2ea4ea..1e71364 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -2005,6 +2005,7 @@
fc_host_supported_classes(shost) =
FC_COS_CLASS2 | FC_COS_CLASS3;
adapter->hydra_version = bottom->adapter_type;
+ adapter->timer_ticks = bottom->timer_interval;
if (fc_host_permanent_port_name(shost) == -1)
fc_host_permanent_port_name(shost) =
fc_host_port_name(shost);
@@ -3649,6 +3650,46 @@
return fsf_req;
}
+static void zfcp_fsf_update_lat(struct fsf_latency_record *lat_rec, u32 lat)
+{
+ lat_rec->sum += lat;
+ if (lat_rec->min > lat)
+ lat_rec->min = lat;
+ if (lat_rec->max < lat)
+ lat_rec->max = lat;
+}
+
+static void zfcp_fsf_req_latency(struct zfcp_fsf_req *fsf_req)
+{
+ struct fsf_qual_latency_info *lat_inf;
+ struct latency_cont *lat;
+ struct zfcp_unit *unit;
+ unsigned long flags;
+
+ lat_inf = &fsf_req->qtcb->prefix.prot_status_qual.latency_info;
+ unit = fsf_req->unit;
+
+ switch (fsf_req->qtcb->bottom.io.data_direction) {
+ case FSF_DATADIR_READ:
+ lat = &unit->latencies.read;
+ break;
+ case FSF_DATADIR_WRITE:
+ lat = &unit->latencies.write;
+ break;
+ case FSF_DATADIR_CMND:
+ lat = &unit->latencies.cmd;
+ break;
+ default:
+ return;
+ }
+
+ spin_lock_irqsave(&unit->latencies.lock, flags);
+ zfcp_fsf_update_lat(&lat->channel, lat_inf->channel_lat);
+ zfcp_fsf_update_lat(&lat->fabric, lat_inf->fabric_lat);
+ lat->counter++;
+ spin_unlock_irqrestore(&unit->latencies.lock, flags);
+}
+
/*
* function: zfcp_fsf_send_fcp_command_handler
*
@@ -3922,6 +3963,9 @@
fcp_rsp_iu->fcp_sns_len);
}
+ if (fsf_req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA)
+ zfcp_fsf_req_latency(fsf_req);
+
/* check FCP_RSP_INFO */
if (unlikely(fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)) {
ZFCP_LOG_DEBUG("rsp_len is valid\n");
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 099970b..8b1a7d9 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -323,11 +323,18 @@
u8 vendor_specific_code;
} __attribute__ ((packed));
+struct fsf_qual_latency_info {
+ u32 channel_lat;
+ u32 fabric_lat;
+ u8 res1[8];
+} __attribute__ ((packed));
+
union fsf_prot_status_qual {
u64 doubleword[FSF_PROT_STATUS_QUAL_SIZE / sizeof(u64)];
struct fsf_qual_version_error version_error;
struct fsf_qual_sequence_error sequence_error;
struct fsf_link_down_info link_down_info;
+ struct fsf_qual_latency_info latency_info;
} __attribute__ ((packed));
struct fsf_qtcb_prefix {
@@ -437,7 +444,9 @@
u32 fc_link_speed;
u32 adapter_type;
u32 peer_d_id;
- u8 res2[12];
+ u8 res1[2];
+ u16 timer_interval;
+ u8 res2[8];
u32 s_id;
struct fsf_nport_serv_param nport_serv_param;
u8 reserved_nport_serv_param[16];