[PATCH 03/14] fcoe: Use per-CPU kernel function for dev_stats instead of an array

Robert Love
2009-03-17T18:41:42Z

Remove the hotplug creation of dev_stats, we allocate for all possible CPUs
now when we allocate the lport.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---

drivers/scsi/fcoe/fcoe_sw.c | 13 +---
drivers/scsi/fcoe/libfcoe.c | 143 +++++------------------------------------
drivers/scsi/libfc/fc_fcp.c | 8 +-
drivers/scsi/libfc/fc_lport.c | 11 ++-
include/scsi/libfc.h | 23 ++++++-
5 files changed, 53 insertions(+), 145 deletions(-)

diff --git a/drivers/scsi/fcoe/fcoe_sw.c b/drivers/scsi/fcoe/fcoe_sw.c
index 2bbbe3c..a675390 100644
--- a/drivers/scsi/fcoe/fcoe_sw.c
+++ b/drivers/scsi/fcoe/fcoe_sw.c
@@ -113,8 +113,6 @@ static struct scsi_host_template fcoe_sw_shost_template = {
*/
static int fcoe_sw_lport_config(struct fc_lport *lp)
{
- int i = 0;
-
lp->link_up = 0;
lp->qfull = 0;
lp->max_retry_count = 3;
@@ -123,12 +121,7 @@ static int fcoe_sw_lport_config(struct fc_lport *lp)
lp->service_params = (FCP_SPPF_INIT_FCN | FCP_SPPF_RD_XRDY_DIS |
FCP_SPPF_RETRY | FCP_SPPF_CONF_COMPL);

- /*
- * allocate per cpu stats block
- */
- for_each_online_cpu(i)
- lp->dev_stats[i] = kzalloc(sizeof(struct fcoe_dev_stats),
- GFP_KERNEL);
+ fc_lport_init_stats(lp);

/* lport fc_lport related configuration */
fc_lport_config(lp);
@@ -311,7 +304,6 @@ static inline int fcoe_sw_em_config(struct fc_lport *lp)
*/
static int fcoe_sw_destroy(struct net_device *netdev)
{
- int cpu;
struct fc_lport *lp = NULL;
struct fcoe_softc *fc;
u8 flogi_maddr[ETH_ALEN];
@@ -363,8 +355,7 @@ static int fcoe_sw_destroy(struct net_device *netdev)
fcoe_clean_pending_queue(lp);

/* Free memory used by statistical counters */
- for_each_online_cpu(cpu)
- kfree(lp->dev_stats[cpu]);
+ fc_lport_free_stats(lp);

/* Release the net_device and Scsi_Host */
dev_put(fc->real_dev);
diff --git a/drivers/scsi/fcoe/libfcoe.c b/drivers/scsi/fcoe/libfcoe.c
index d22275b..648a2fc 100644
--- a/drivers/scsi/fcoe/libfcoe.c
+++ b/drivers/scsi/fcoe/libfcoe.c
@@ -71,9 +71,6 @@ DEFINE_PER_CPU(struct fcoe_percpu_s, fcoe_percpu);
/* Function Prototyes */
static int fcoe_check_wait_queue(struct fc_lport *);
static void fcoe_recv_flogi(struct fcoe_softc *, struct fc_frame *, u8 *);
-#ifdef CONFIG_HOTPLUG_CPU
-static int fcoe_cpu_callback(struct notifier_block *, ulong, void *);
-#endif /* CONFIG_HOTPLUG_CPU */
static int fcoe_device_notification(struct notifier_block *, ulong, void *);
static void fcoe_dev_setup(void);
static void fcoe_dev_cleanup(void);
@@ -83,87 +80,6 @@ static struct notifier_block fcoe_notifier = {
.notifier_call = fcoe_device_notification,
};

-
-#ifdef CONFIG_HOTPLUG_CPU
-static struct notifier_block fcoe_cpu_notifier = {
- .notifier_call = fcoe_cpu_callback,
-};
-
-/**
- * fcoe_create_percpu_data() - creates the associated cpu data
- * @cpu: index for the cpu where fcoe cpu data will be created
- *
- * create percpu stats block, from cpu add notifier
- *
- * Returns: none
- */
-static void fcoe_create_percpu_data(unsigned int cpu)
-{
- struct fc_lport *lp;
- struct fcoe_softc *fc;
-
- write_lock_bh(&fcoe_hostlist_lock);
- list_for_each_entry(fc, &fcoe_hostlist, list) {
- lp = fc->lp;
- if (lp->dev_stats[cpu] == NULL)
- lp->dev_stats[cpu] =
- kzalloc(sizeof(struct fcoe_dev_stats),
- GFP_KERNEL);
- }
- write_unlock_bh(&fcoe_hostlist_lock);
-}
-
-/**
- * fcoe_destroy_percpu_data() - destroys the associated cpu data
- * @cpu: index for the cpu where fcoe cpu data will destroyed
- *
- * destroy percpu stats block called by cpu add/remove notifier
- *
- * Retuns: none
- */
-static void fcoe_destroy_percpu_data(unsigned int cpu)
-{
- struct fc_lport *lp;
- struct fcoe_softc *fc;
-
- write_lock_bh(&fcoe_hostlist_lock);
- list_for_each_entry(fc, &fcoe_hostlist, list) {
- lp = fc->lp;
- kfree(lp->dev_stats[cpu]);
- lp->dev_stats[cpu] = NULL;
- }
- write_unlock_bh(&fcoe_hostlist_lock);
-}
-
-/**
- * fcoe_cpu_callback() - fcoe cpu hotplug event callback
- * @nfb: callback data block
- * @action: event triggering the callback
- * @hcpu: index for the cpu of this event
- *
- * this creates or destroys per cpu data for fcoe
- *
- * Returns NOTIFY_OK always.
- */
-static int fcoe_cpu_callback(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
-{
- unsigned int cpu = (unsigned long)hcpu;
-
- switch (action) {
- case CPU_ONLINE:
- fcoe_create_percpu_data(cpu);
- break;
- case CPU_DEAD:
- fcoe_destroy_percpu_data(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-
/**
* fcoe_rcv() - this is the fcoe receive function called by NET_RX_SOFTIRQ
* @skb: the receive skb
@@ -181,7 +97,6 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *dev,
struct fc_lport *lp;
struct fcoe_rcv_info *fr;
struct fcoe_softc *fc;
- struct fcoe_dev_stats *stats;
struct fc_frame_header *fh;
struct fcoe_percpu_s *fps;
unsigned short oxid;
@@ -252,13 +167,7 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *dev,

return 0;
err:
-#ifdef CONFIG_SMP
- stats = lp->dev_stats[smp_processor_id()];
-#else
- stats = lp->dev_stats[0];
-#endif
- if (stats)
- stats->ErrorFrames++;
+ fc_lport_get_stats(lp)->ErrorFrames++;

err2:
kfree_skb(skb);
@@ -495,11 +404,9 @@ int fcoe_xmit(struct fc_lport *lp, struct fc_frame *fp)
}
#endif
/* update tx stats: regardless if LLD fails */
- stats = lp->dev_stats[smp_processor_id()];
- if (stats) {
- stats->TxFrames++;
- stats->TxWords += wlen;
- }
+ stats = fc_lport_get_stats(lp);
+ stats->TxFrames++;
+ stats->TxWords += wlen;

/* send down to lld */
fr_dev(fp) = lp;
@@ -565,8 +472,6 @@ int fcoe_percpu_receive_thread(void *arg)
continue;
}

- stats = lp->dev_stats[smp_processor_id()];
-
if (unlikely(debug_fcoe)) {
FC_DBG("skb_info: len:%d data_len:%d head:%p data:%p "
"tail:%p end:%p sum:%d dev:%s",
@@ -593,13 +498,16 @@ int fcoe_percpu_receive_thread(void *arg)
hp = (struct fcoe_hdr *) skb_network_header(skb);
fh = (struct fc_frame_header *) skb_transport_header(skb);

+ stats = fc_lport_get_stats(lp);
if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
- if (stats) {
- if (stats->ErrorFrames < 5)
- FC_DBG("unknown FCoE version %x",
- FC_FCOE_DECAPS_VER(hp));
- stats->ErrorFrames++;
- }
+ if (stats->ErrorFrames < 5)
+ printk(KERN_WARNING "FCoE version "
+ "mismatch: The frame has "
+ "version %x, but the "
+ "initiator supports version "
+ "%x\n", FC_FCOE_DECAPS_VER(hp),
+ FC_FCOE_VER);
+ stats->ErrorFrames++;
kfree_skb(skb);
continue;
}
@@ -607,10 +515,8 @@ int fcoe_percpu_receive_thread(void *arg)
skb_pull(skb, sizeof(struct fcoe_hdr));
fr_len = skb->len - sizeof(struct fcoe_crc_eof);

- if (stats) {
- stats->RxFrames++;
- stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
- }
+ stats->RxFrames++;
+ stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;

fp = (struct fc_frame *)skb;
fc_frame_init(fp);
@@ -885,9 +791,8 @@ static int fcoe_device_notification(struct notifier_block *notifier,
if (new_link_up)
fc_linkup(lp);
else {
- stats = lp->dev_stats[smp_processor_id()];
- if (stats)
- stats->LinkFailureCount++;
+ stats = fc_lport_get_stats(lp);
+ stats->LinkFailureCount++;
fc_linkdown(lp);
fcoe_clean_pending_queue(lp);
}
@@ -1371,10 +1276,6 @@ static int __init fcoe_init(void)
INIT_LIST_HEAD(&fcoe_hostlist);
rwlock_init(&fcoe_hostlist_lock);

-#ifdef CONFIG_HOTPLUG_CPU
- register_cpu_notifier(&fcoe_cpu_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
-
for_each_possible_cpu(cpu) {
p = &per_cpu(fcoe_percpu, cpu);
skb_queue_head_init(&p->fcoe_rx_list);
@@ -1430,17 +1331,9 @@ static void __exit fcoe_exit(void)
struct fcoe_percpu_s *p;
struct sk_buff *skb;

- /*
- * Stop all call back interfaces
- */
-#ifdef CONFIG_HOTPLUG_CPU
- unregister_cpu_notifier(&fcoe_cpu_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
fcoe_dev_cleanup();

- /*
- * stop timer
- */
+ /* Stop the timer */
del_timer_sync(&fcoe_timer);

/* releases the associated fcoe transport for each lport */
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
index a5725f3..0997e8b 100644
--- a/drivers/scsi/libfc/fc_fcp.c
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -407,10 +407,12 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)

if (~crc != le32_to_cpu(fr_crc(fp))) {
crc_err:
- stats = lp->dev_stats[smp_processor_id()];
+ stats = fc_lport_get_stats(lp);
stats->ErrorFrames++;
+ /* FIXME - per cpu count, not total count! */
if (stats->InvalidCRCCount++ < 5)
- FC_DBG("CRC error on data frame\n");
+ printk(KERN_WARNING "CRC error on data frame for port (%6x)\n",
+ fc_host_port_id(lp->host));
/*
* Assume the frame is total garbage.
* We may have copied it over the good part
@@ -1752,7 +1754,7 @@ int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
/*
* setup the data direction
*/
- stats = lp->dev_stats[smp_processor_id()];
+ stats = fc_lport_get_stats(lp);
if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
fsp->req_flags = FC_SRB_READ;
stats->InputRequests++;
diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 7ef4450..ae6ca6a 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -267,10 +267,10 @@ EXPORT_SYMBOL(fc_get_host_speed);

struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
{
- int i;
struct fc_host_statistics *fcoe_stats;
struct fc_lport *lp = shost_priv(shost);
struct timespec v0, v1;
+ unsigned int cpu;

fcoe_stats = &lp->host_stats;
memset(fcoe_stats, 0, sizeof(struct fc_host_statistics));
@@ -279,10 +279,11 @@ struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
jiffies_to_timespec(lp->boot_time, &v1);
fcoe_stats->seconds_since_last_reset = (v0.tv_sec - v1.tv_sec);

- for_each_online_cpu(i) {
- struct fcoe_dev_stats *stats = lp->dev_stats[i];
- if (stats == NULL)
- continue;
+ for_each_possible_cpu(cpu) {
+ struct fcoe_dev_stats *stats;
+
+ stats = percpu_ptr(lp->dev_stats, cpu);
+
fcoe_stats->tx_frames += stats->TxFrames;
fcoe_stats->tx_words += stats->TxWords;
fcoe_stats->rx_frames += stats->RxFrames;
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index a70eafa..4e1d394 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -22,6 +22,7 @@

#include <linux/timer.h>
#include <linux/if.h>
+#include <linux/percpu.h>

#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_fc.h>
@@ -661,7 +662,8 @@ struct fc_lport {
unsigned long boot_time;

struct fc_host_statistics host_stats;
- struct fcoe_dev_stats *dev_stats[NR_CPUS];
+ struct fcoe_dev_stats *dev_stats;
+
u64 wwpn;
u64 wwnn;
u8 retry_count;
@@ -722,6 +724,25 @@ static inline void fc_lport_state_enter(struct fc_lport *lp,
lp->state = state;
}

+static inline int fc_lport_init_stats(struct fc_lport *lp)
+{
+ /* allocate per cpu stats block */
+ lp->dev_stats = alloc_percpu(struct fcoe_dev_stats);
+ if (!lp->dev_stats)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void fc_lport_free_stats(struct fc_lport *lp)
+{
+ free_percpu(lp->dev_stats);
+}
+
+static inline struct fcoe_dev_stats *fc_lport_get_stats(struct fc_lport *lp)
+{
+ return per_cpu_ptr(lp->dev_stats, smp_processor_id());
+}
+

/*
* LOCAL PORT LAYER