Messages in this thread | | | Date | Mon, 21 Mar 2022 17:07:55 +0100 | From | Ansuel Smith <> | Subject | Re: [net-next PATCH v2] net: dsa: qca8k: pack driver struct and improve cache use |
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On Thu, Mar 03, 2022 at 03:53:27AM +0200, Vladimir Oltean wrote: > On Mon, Feb 28, 2022 at 12:04:08PM +0100, Ansuel Smith wrote: > > Pack qca8k priv and other struct using pahole and set the first priv > > struct entry to mgmt_master and mgmt_eth_data to speedup access. > > While at it also rework pcs struct and move it qca8k_ports_config > > following other configuration set for the cpu ports. > > > > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com> > > --- > > How did you "pack" struct qca8k_priv exactly? >
I'm trying to understand it too... also this was done basend on what target?
> Before: > > struct qca8k_priv { > u8 switch_id; /* 0 1 */ > u8 switch_revision; /* 1 1 */ > u8 mirror_rx; /* 2 1 */ > u8 mirror_tx; /* 3 1 */ > u8 lag_hash_mode; /* 4 1 */ > bool legacy_phy_port_mapping; /* 5 1 */ > struct qca8k_ports_config ports_config; /* 6 7 */ > > /* XXX 3 bytes hole, try to pack */ > > struct regmap * regmap; /* 16 8 */ > struct mii_bus * bus; /* 24 8 */ > struct ar8xxx_port_status port_sts[7]; /* 32 28 */ > > /* XXX 4 bytes hole, try to pack */ > > /* --- cacheline 1 boundary (64 bytes) --- */ > struct dsa_switch * ds; /* 64 8 */ > struct mutex reg_mutex; /* 72 160 */ > /* --- cacheline 3 boundary (192 bytes) was 40 bytes ago --- */ > struct device * dev; /* 232 8 */ > struct dsa_switch_ops ops; /* 240 864 */ > /* --- cacheline 17 boundary (1088 bytes) was 16 bytes ago --- */ > struct gpio_desc * reset_gpio; /* 1104 8 */ > unsigned int port_mtu[7]; /* 1112 28 */ > > /* XXX 4 bytes hole, try to pack */ > > struct net_device * mgmt_master; /* 1144 8 */ > /* --- cacheline 18 boundary (1152 bytes) --- */ > struct qca8k_mgmt_eth_data mgmt_eth_data; /* 1152 280 */ > /* --- cacheline 22 boundary (1408 bytes) was 24 bytes ago --- */ > struct qca8k_mib_eth_data mib_eth_data; /* 1432 272 */ > /* --- cacheline 26 boundary (1664 bytes) was 40 bytes ago --- */ > struct qca8k_mdio_cache mdio_cache; /* 1704 6 */ > > /* XXX 2 bytes hole, try to pack */ > > struct qca8k_pcs pcs_port_0; /* 1712 32 */ > > /* XXX last struct has 4 bytes of padding */ > > /* --- cacheline 27 boundary (1728 bytes) was 16 bytes ago --- */ > struct qca8k_pcs pcs_port_6; /* 1744 32 */ > > /* XXX last struct has 4 bytes of padding */ > > /* size: 1776, cachelines: 28, members: 22 */ > /* sum members: 1763, holes: 4, sum holes: 13 */ > /* paddings: 2, sum paddings: 8 */ > /* last cacheline: 48 bytes */ > }; > > After: > > struct qca8k_priv { > struct net_device * mgmt_master; /* 0 8 */ > struct qca8k_mgmt_eth_data mgmt_eth_data; /* 8 280 */ > /* --- cacheline 4 boundary (256 bytes) was 32 bytes ago --- */ > struct qca8k_mdio_cache mdio_cache; /* 288 6 */ > u8 switch_id; /* 294 1 */ > u8 switch_revision; /* 295 1 */ > u8 mirror_rx; /* 296 1 */ > u8 mirror_tx; /* 297 1 */ > u8 lag_hash_mode; /* 298 1 */ > bool legacy_phy_port_mapping; /* 299 1 */ > > /* XXX 4 bytes hole, try to pack */ > > struct qca8k_ports_config ports_config; /* 304 72 */ > /* --- cacheline 5 boundary (320 bytes) was 56 bytes ago --- */ > struct regmap * regmap; /* 376 8 */ > /* --- cacheline 6 boundary (384 bytes) --- */ > struct mii_bus * bus; /* 384 8 */ > struct ar8xxx_port_status port_sts[7]; /* 392 28 */ > > /* XXX 4 bytes hole, try to pack */ > > struct dsa_switch * ds; /* 424 8 */ > struct mutex reg_mutex; /* 432 160 */ > /* --- cacheline 9 boundary (576 bytes) was 16 bytes ago --- */ > struct device * dev; /* 592 8 */ > struct gpio_desc * reset_gpio; /* 600 8 */ > struct dsa_switch_ops ops; /* 608 864 */ > /* --- cacheline 23 boundary (1472 bytes) --- */ > struct qca8k_mib_eth_data mib_eth_data; /* 1472 280 */ > > /* XXX last struct has 4 bytes of padding */ > > /* --- cacheline 27 boundary (1728 bytes) was 24 bytes ago --- */ > unsigned int port_mtu[7]; /* 1752 28 */ > > /* size: 1784, cachelines: 28, members: 20 */ > /* sum members: 1772, holes: 2, sum holes: 8 */ > /* padding: 4 */ > /* paddings: 1, sum paddings: 4 */ > /* last cacheline: 56 bytes */ > }; > > 1776 vs 1784. That's... larger?! > > Also, struct qca8k_priv is so large because the "ops" member is a full > copy of qca8k_switch_ops. I understand why commit db460c54b67f ("net: > dsa: qca8k: extend slave-bus implementations") did this, but I wonder, > is there no better way? >
Actually from what I can see the struct can be improved in 2 way... The ancient struct ar8xxx_port_status port_sts[QCA8K_NUM_PORTS]; can be totally dropped as I can't see why we still need it.
The duplicated ops is funny. I could be very confused but why it's done like that? Can't we modify directly the already defined one and drop struct dsa_switch_ops ops; from qca8k_priv?
I mean is all of that to use priv->ops.phy_read instead of priv->ds->ops.phy_read or even qca8k_switch_ops directly? o.o
Am I missing something?
> > drivers/net/dsa/qca8k.c | 8 ++++---- > > drivers/net/dsa/qca8k.h | 33 ++++++++++++++++----------------- > > 2 files changed, 20 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c > > index ee0dbf324268..8d059da5f0ca 100644 > > --- a/drivers/net/dsa/qca8k.c > > +++ b/drivers/net/dsa/qca8k.c > > @@ -1685,11 +1685,11 @@ qca8k_phylink_mac_select_pcs(struct dsa_switch *ds, int port, > > case PHY_INTERFACE_MODE_1000BASEX: > > switch (port) { > > case 0: > > - pcs = &priv->pcs_port_0.pcs; > > + pcs = &priv->ports_config.qpcs[QCA8K_CPU_PORT0].pcs; > > break; > > > > case 6: > > - pcs = &priv->pcs_port_6.pcs; > > + pcs = &priv->ports_config.qpcs[QCA8K_CPU_PORT6].pcs; > > break; > > } > > break; > > @@ -2889,8 +2889,8 @@ qca8k_setup(struct dsa_switch *ds) > > if (ret) > > return ret; > > > > - qca8k_setup_pcs(priv, &priv->pcs_port_0, 0); > > - qca8k_setup_pcs(priv, &priv->pcs_port_6, 6); > > + qca8k_setup_pcs(priv, &priv->ports_config.qpcs[QCA8K_CPU_PORT0], 0); > > + qca8k_setup_pcs(priv, &priv->ports_config.qpcs[QCA8K_CPU_PORT6], 6); > > > > /* Make sure MAC06 is disabled */ > > ret = regmap_clear_bits(priv->regmap, QCA8K_REG_PORT0_PAD_CTRL, > > diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h > > index f375627174c8..611dc2335dbe 100644 > > --- a/drivers/net/dsa/qca8k.h > > +++ b/drivers/net/dsa/qca8k.h > > @@ -341,18 +341,24 @@ enum { > > > > struct qca8k_mgmt_eth_data { > > struct completion rw_done; > > - struct mutex mutex; /* Enforce one mdio read/write at time */ > > + u32 data[4]; > > bool ack; > > u32 seq; > > - u32 data[4]; > > + struct mutex mutex; /* Enforce one mdio read/write at time */ > > }; > > > > struct qca8k_mib_eth_data { > > struct completion rw_done; > > + u64 *data; /* pointer to ethtool data */ > > + u8 req_port; > > struct mutex mutex; /* Process one command at time */ > > refcount_t port_parsed; /* Counter to track parsed port */ > > - u8 req_port; > > - u64 *data; /* pointer to ethtool data */ > > +}; > > + > > +struct qca8k_pcs { > > + struct phylink_pcs pcs; > > + struct qca8k_priv *priv; > > + int port; > > }; > > > > struct qca8k_ports_config { > > @@ -361,6 +367,7 @@ struct qca8k_ports_config { > > bool sgmii_enable_pll; > > u8 rgmii_rx_delay[QCA8K_NUM_CPU_PORTS]; /* 0: CPU port0, 1: CPU port6 */ > > u8 rgmii_tx_delay[QCA8K_NUM_CPU_PORTS]; /* 0: CPU port0, 1: CPU port6 */ > > + struct qca8k_pcs qpcs[QCA8K_NUM_CPU_PORTS]; > > }; > > > > struct qca8k_mdio_cache { > > @@ -376,13 +383,10 @@ struct qca8k_mdio_cache { > > u16 hi; > > }; > > > > -struct qca8k_pcs { > > - struct phylink_pcs pcs; > > - struct qca8k_priv *priv; > > - int port; > > -}; > > - > > struct qca8k_priv { > > + struct net_device *mgmt_master; /* Track if mdio/mib Ethernet is available */ > > + struct qca8k_mgmt_eth_data mgmt_eth_data; > > + struct qca8k_mdio_cache mdio_cache; > > u8 switch_id; > > u8 switch_revision; > > u8 mirror_rx; > > @@ -396,15 +400,10 @@ struct qca8k_priv { > > struct dsa_switch *ds; > > struct mutex reg_mutex; > > struct device *dev; > > - struct dsa_switch_ops ops; > > struct gpio_desc *reset_gpio; > > - unsigned int port_mtu[QCA8K_NUM_PORTS]; > > - struct net_device *mgmt_master; /* Track if mdio/mib Ethernet is available */ > > - struct qca8k_mgmt_eth_data mgmt_eth_data; > > + struct dsa_switch_ops ops; > > struct qca8k_mib_eth_data mib_eth_data; > > - struct qca8k_mdio_cache mdio_cache; > > - struct qca8k_pcs pcs_port_0; > > - struct qca8k_pcs pcs_port_6; > > + unsigned int port_mtu[QCA8K_NUM_PORTS]; > > }; > > > > struct qca8k_mib_desc { > > -- > > 2.34.1 > > >
-- Ansuel
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