For performance monitoring, trace time intervals when Tx vring
is idle/not idle. Use CPU cycle counter for this, because jiffies is
too rough, and other precise time measurement methods involve
overhead while get_cycles() should be fast.
This used to provide some estimation for percentage when Tx vring
was idle, i.e. when hardware is under-utilized.
Estimation is not precise because of many reasons - CPU frequency scaling,
grt_cycles() may be per core etc. But still, it is good estimation
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@xxxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/wil6210/debugfs.c | 16 ++++++++++++++--
drivers/net/wireless/ath/wil6210/txrx.c | 8 +++++++-
drivers/net/wireless/ath/wil6210/wil6210.h | 3 ++-
3 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index d90aa28..9c11023 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -69,6 +69,8 @@ static int wil_vring_debugfs_show(struct seq_file *s, void *data)
for (i = 0; i < ARRAY_SIZE(wil->vring_tx); i++) {
struct vring *vring = &(wil->vring_tx[i]);
+ struct vring_tx_data *txdata = &wil->vring_tx_data[i];
+
if (vring->va) {
int cid = wil->vring2cid_tid[i][0];
int tid = wil->vring2cid_tid[i][1];
@@ -78,10 +80,20 @@ static int wil_vring_debugfs_show(struct seq_file *s, void *data)
% vring->size;
int avail = vring->size - used - 1;
char name[10];
+ /* performance monitoring */
+ cycles_t now = get_cycles();
+ cycles_t idle = txdata->idle;
+ cycles_t total = now - txdata->begin;
+
+ txdata->begin = now;
+ txdata->idle = 0ULL;
+
snprintf(name, sizeof(name), "tx_%2d", i);
- seq_printf(s, "\n%pM CID %d TID %d [%3d|%3d]\n",
- wil->sta[cid].addr, cid, tid, used, avail);
+ seq_printf(s, "\n%pM CID %d TID %d [%3d|%3d] idle %3d%%\n",
+ wil->sta[cid].addr, cid, tid, used, avail,
+ (int)((idle*100)/total));
+
wil_print_vring(s, wil, name, vring, '_', 'H');
}
}
diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index c08d041..0318cd2 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -881,6 +881,7 @@ static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
int nr_frags = skb_shinfo(skb)->nr_frags;
uint f = 0;
int vring_index = vring - wil->vring_tx;
+ struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
uint i = swhead;
dma_addr_t pa;
@@ -953,6 +954,9 @@ static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
(const void *)d, sizeof(*d), false);
+ if (wil_vring_is_empty(vring)) /* performance monitoring */
+ txdata->idle += get_cycles() - txdata->last_idle;
+
/* advance swhead */
wil_vring_advance_head(vring, nr_frags + 1);
wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
@@ -1133,8 +1137,10 @@ int wil_tx_complete(struct wil6210_priv *wil, int ringid)
}
}
- if (wil_vring_is_empty(vring))
+ if (wil_vring_is_empty(vring)) { /* performance monitoring */
wil_dbg_txrx(wil, "Ring[%2d] empty\n", ringid);
+ txdata->last_idle = get_cycles();
+ }
if (wil_vring_avail_tx(vring) > wil_vring_wmark_high(vring))
netif_tx_wake_all_queues(wil_to_ndev(wil));
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 793675e..ede4c9f 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -20,6 +20,7 @@
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <net/cfg80211.h>
+#include <linux/timex.h>
#define WIL_NAME "wil6210"
@@ -251,7 +252,7 @@ struct vring {
*/
struct vring_tx_data {
int enabled;
-
+ cycles_t idle, last_idle, begin;
};
enum { /* for wil6210_priv.status */
--
1.9.1
--
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