* [PATCH net-next 1/2] net: dsa: mv88e6xxx: Release mutex between each statistics read
2018-02-15 13:38 [PATCH net-next 0/2] net: dsa: mv88e6xxx: Improve PTP access latency Andrew Lunn
@ 2018-02-15 13:38 ` Andrew Lunn
2018-02-15 13:38 ` [PATCH net-next 2/2] net: dsa: mv88e6xxx: Release mutex between each ATU read Andrew Lunn
2018-02-16 20:37 ` [PATCH net-next 0/2] net: dsa: mv88e6xxx: Improve PTP access latency David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Lunn @ 2018-02-15 13:38 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Vivien Didelot, Andrew Lunn
The PTP code needs low latency access to the PTP hardware timestamps.
Reading all the statistics in one go adds a lot of latency to the PTP
code. So take and release the reg_lock mutex for each individual
statistics, allowing the PTP thread jump in between.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/dsa/mv88e6xxx/chip.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index af63710e93c1..bd5cb8a0330e 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -714,9 +714,12 @@ static void mv88e6xxx_stats_get_stats(struct mv88e6xxx_chip *chip, int port,
for (i = 0, j = 0; i < ARRAY_SIZE(mv88e6xxx_hw_stats); i++) {
stat = &mv88e6xxx_hw_stats[i];
if (stat->type & types) {
+ mutex_lock(&chip->reg_lock);
data[j] = _mv88e6xxx_get_ethtool_stat(chip, stat, port,
bank1_select,
histogram);
+ mutex_unlock(&chip->reg_lock);
+
j++;
}
}
@@ -764,14 +767,13 @@ static void mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds, int port,
mutex_lock(&chip->reg_lock);
ret = mv88e6xxx_stats_snapshot(chip, port);
- if (ret < 0) {
- mutex_unlock(&chip->reg_lock);
+ mutex_unlock(&chip->reg_lock);
+
+ if (ret < 0)
return;
- }
mv88e6xxx_get_stats(chip, port, data);
- mutex_unlock(&chip->reg_lock);
}
static int mv88e6xxx_stats_set_histogram(struct mv88e6xxx_chip *chip)
--
2.15.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH net-next 2/2] net: dsa: mv88e6xxx: Release mutex between each ATU read
2018-02-15 13:38 [PATCH net-next 0/2] net: dsa: mv88e6xxx: Improve PTP access latency Andrew Lunn
2018-02-15 13:38 ` [PATCH net-next 1/2] net: dsa: mv88e6xxx: Release mutex between each statistics read Andrew Lunn
@ 2018-02-15 13:38 ` Andrew Lunn
2018-02-16 20:37 ` [PATCH net-next 0/2] net: dsa: mv88e6xxx: Improve PTP access latency David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Lunn @ 2018-02-15 13:38 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Vivien Didelot, Andrew Lunn
The PTP code needs low latency access to the PTP hardware timestamps.
Reading all the ATU entries in one go adds a lot of latency to the PTP
code. So take and release the reg_lock mutex for each individual MAC
address in the ATU, allowing the PTP thread jump in between.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/dsa/mv88e6xxx/chip.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index bd5cb8a0330e..39c7ad7e490f 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -1437,7 +1437,9 @@ static int mv88e6xxx_port_db_dump_fid(struct mv88e6xxx_chip *chip,
eth_broadcast_addr(addr.mac);
do {
+ mutex_lock(&chip->reg_lock);
err = mv88e6xxx_g1_atu_getnext(chip, fid, &addr);
+ mutex_unlock(&chip->reg_lock);
if (err)
return err;
@@ -1470,7 +1472,10 @@ static int mv88e6xxx_port_db_dump(struct mv88e6xxx_chip *chip, int port,
int err;
/* Dump port's default Filtering Information Database (VLAN ID 0) */
+ mutex_lock(&chip->reg_lock);
err = mv88e6xxx_port_get_fid(chip, port, &fid);
+ mutex_unlock(&chip->reg_lock);
+
if (err)
return err;
@@ -1480,7 +1485,9 @@ static int mv88e6xxx_port_db_dump(struct mv88e6xxx_chip *chip, int port,
/* Dump VLANs' Filtering Information Databases */
do {
+ mutex_lock(&chip->reg_lock);
err = mv88e6xxx_vtu_getnext(chip, &vlan);
+ mutex_unlock(&chip->reg_lock);
if (err)
return err;
@@ -1500,13 +1507,8 @@ static int mv88e6xxx_port_fdb_dump(struct dsa_switch *ds, int port,
dsa_fdb_dump_cb_t *cb, void *data)
{
struct mv88e6xxx_chip *chip = ds->priv;
- int err;
-
- mutex_lock(&chip->reg_lock);
- err = mv88e6xxx_port_db_dump(chip, port, cb, data);
- mutex_unlock(&chip->reg_lock);
- return err;
+ return mv88e6xxx_port_db_dump(chip, port, cb, data);
}
static int mv88e6xxx_bridge_map(struct mv88e6xxx_chip *chip,
--
2.15.1
^ permalink raw reply related [flat|nested] 4+ messages in thread