[RFC net-next 0/2] Add page_pool_stats ethtool APIs

[RFC net-next 0/2] Add page_pool_stats ethtool APIs

[Lorenzo Bianconi]

Introduce page_pool_stats support to mvneta driver.

Lorenzo Bianconi (2):
  net: page_pool: introduce ethtool stats
  net: mvneta: add support for page_pool_get_stats

 drivers/net/ethernet/marvell/Kconfig  |  1 +
 drivers/net/ethernet/marvell/mvneta.c | 59 ++++++++++++++--
 include/net/page_pool.h               | 24 +++++++
 net/core/page_pool.c                  | 96 +++++++++++++++++++++++++++
 4 files changed, 175 insertions(+), 5 deletions(-)

-- 
2.35.1

[RFC net-next 1/2] net: page_pool: introduce ethtool stats

[Lorenzo Bianconi]

Introduce APIs to report page_pool stats through ethtool and reduce
duplicated code in each driver.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/net/page_pool.h | 24 +++++++++++
 net/core/page_pool.c    | 96 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)

diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index ea5fb70e5101..17fb15b49f1a 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -117,6 +117,30 @@ struct page_pool_stats {
 	struct page_pool_recycle_stats recycle_stats;
 };
 
+/* List of page_pool stats exported through ethtool. */
+enum {
+	PP_ETHTOOL_ALLOC_FAST,
+	PP_ETHTOOL_ALLOC_SLOW,
+	PP_ETHTOOL_ALLOC_SLOW_HIGH_ORDER,
+	PP_ETHTOOL_ALLOC_EMPTY,
+	PP_ETHTOOL_ALLOC_REFILL,
+	PP_ETHTOOL_ALLOC_WAIVE,
+	PP_ETHTOOL_RECYCLE_CACHED,
+	PP_ETHTOOL_RECYCLE_CACHE_FULL,
+	PP_ETHTOOL_RECYCLE_RING,
+	PP_ETHTOOL_RECYCLE_RING_FULL,
+	PP_ETHTOOL_RECYCLE_RELEASED_REF,
+	PP_ETHTOOL_STATS_MAX,
+};
+
+static inline int page_pool_ethtool_stats_get_count(void)
+{
+	return PP_ETHTOOL_STATS_MAX;
+}
+
+void page_pool_ethtool_stats_get_strings(u8 *data);
+void page_pool_ethtool_stats_get(u64 *data, struct page_pool_stats *stats);
+
 /*
  * Drivers that wish to harvest page pool stats and report them to users
  * (perhaps via ethtool, debugfs, or another mechanism) can allocate a
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 4af55d28ffa3..7f24fc2fe58d 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -18,6 +18,7 @@
 #include <linux/page-flags.h>
 #include <linux/mm.h> /* for __put_page() */
 #include <linux/poison.h>
+#include <linux/ethtool.h>
 
 #include <trace/events/page_pool.h>
 
@@ -66,6 +67,101 @@ bool page_pool_get_stats(struct page_pool *pool,
 	return true;
 }
 EXPORT_SYMBOL(page_pool_get_stats);
+
+void page_pool_ethtool_stats_get_strings(u8 *data)
+{
+	static const struct {
+		u8 type;
+		char name[ETH_GSTRING_LEN];
+	} stats[PP_ETHTOOL_STATS_MAX] = {
+		{
+			.type = PP_ETHTOOL_ALLOC_FAST,
+			.name = "rx_pp_alloc_fast"
+		}, {
+			.type = PP_ETHTOOL_ALLOC_SLOW,
+			.name = "rx_pp_alloc_slow"
+		}, {
+			.type = PP_ETHTOOL_ALLOC_SLOW_HIGH_ORDER,
+			.name = "rx_pp_alloc_slow_ho"
+		}, {
+			.type = PP_ETHTOOL_ALLOC_EMPTY,
+			.name = "rx_pp_alloc_empty"
+		}, {
+			.type = PP_ETHTOOL_ALLOC_REFILL,
+			.name = "rx_pp_alloc_refill"
+		}, {
+			.type = PP_ETHTOOL_ALLOC_WAIVE,
+			.name = "rx_pp_alloc_waive"
+		}, {
+			.type = PP_ETHTOOL_RECYCLE_CACHED,
+			.name = "rx_pp_recycle_cached"
+		}, {
+			.type = PP_ETHTOOL_RECYCLE_CACHE_FULL,
+			.name = "rx_pp_recycle_cache_full"
+		}, {
+			.type = PP_ETHTOOL_RECYCLE_RING,
+			.name = "rx_pp_recycle_ring"
+		}, {
+			.type = PP_ETHTOOL_RECYCLE_RING_FULL,
+			.name = "rx_pp_recycle_ring_full"
+		}, {
+			.type = PP_ETHTOOL_RECYCLE_RELEASED_REF,
+			.name = "rx_pp_recycle_released_ref"
+		},
+	};
+	int i;
+
+	for (i = 0; i < PP_ETHTOOL_STATS_MAX; i++) {
+		memcpy(data, stats[i].name, ETH_GSTRING_LEN);
+		data += ETH_GSTRING_LEN;
+	}
+
+}
+EXPORT_SYMBOL(page_pool_ethtool_stats_get_strings);
+
+void page_pool_ethtool_stats_get(u64 *data, struct page_pool_stats *stats)
+{
+	int i;
+
+	for (i = 0; i < PP_ETHTOOL_STATS_MAX; i++) {
+		switch (i) {
+		case PP_ETHTOOL_ALLOC_FAST:
+			*data++ = stats->alloc_stats.fast;
+			break;
+		case PP_ETHTOOL_ALLOC_SLOW:
+			*data++ = stats->alloc_stats.slow;
+			break;
+		case PP_ETHTOOL_ALLOC_SLOW_HIGH_ORDER:
+			*data++ = stats->alloc_stats.slow_high_order;
+			break;
+		case PP_ETHTOOL_ALLOC_EMPTY:
+			*data++ = stats->alloc_stats.empty;
+			break;
+		case PP_ETHTOOL_ALLOC_REFILL:
+			*data++ = stats->alloc_stats.refill;
+			break;
+		case PP_ETHTOOL_ALLOC_WAIVE:
+			*data++ = stats->alloc_stats.waive;
+			break;
+		case PP_ETHTOOL_RECYCLE_CACHED:
+			*data++ = stats->recycle_stats.cached;
+			break;
+		case PP_ETHTOOL_RECYCLE_CACHE_FULL:
+			*data++ = stats->recycle_stats.cache_full;
+			break;
+		case PP_ETHTOOL_RECYCLE_RING:
+			*data++ = stats->recycle_stats.ring;
+			break;
+		case PP_ETHTOOL_RECYCLE_RING_FULL:
+			*data++ = stats->recycle_stats.ring_full;
+			break;
+		case PP_ETHTOOL_RECYCLE_RELEASED_REF:
+			*data++ = stats->recycle_stats.released_refcnt;
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(page_pool_ethtool_stats_get);
 #else
 #define alloc_stat_inc(pool, __stat)
 #define recycle_stat_inc(pool, __stat)
-- 
2.35.1

Re: [RFC net-next 1/2] net: page_pool: introduce ethtool stats

[Jakub Kicinski]

On Thu,  7 Apr 2022 18:55:04 +0200 Lorenzo Bianconi wrote:
> +void page_pool_ethtool_stats_get_strings(u8 *data)

This needs to return the pointer to after the used area, so drivers can
append more stats. Or make data double pointer and update it before
returning.

> +{
> +	static const struct {
> +		u8 type;
> +		char name[ETH_GSTRING_LEN];
> +	} stats[PP_ETHTOOL_STATS_MAX] = {
> +		{
> +			.type = PP_ETHTOOL_ALLOC_FAST,

Why enumerate the type? It's not used.

> +			.name = "rx_pp_alloc_fast"
> +		}, {
> +			.type = PP_ETHTOOL_ALLOC_SLOW,
> +			.name = "rx_pp_alloc_slow"
> +		}, {
> +			.type = PP_ETHTOOL_ALLOC_SLOW_HIGH_ORDER,
> +			.name = "rx_pp_alloc_slow_ho"
> +		}, {
> +			.type = PP_ETHTOOL_ALLOC_EMPTY,
> +			.name = "rx_pp_alloc_empty"
> +		}, {
> +			.type = PP_ETHTOOL_ALLOC_REFILL,
> +			.name = "rx_pp_alloc_refill"
> +		}, {
> +			.type = PP_ETHTOOL_ALLOC_WAIVE,
> +			.name = "rx_pp_alloc_waive"
> +		}, {
> +			.type = PP_ETHTOOL_RECYCLE_CACHED,
> +			.name = "rx_pp_recycle_cached"
> +		}, {
> +			.type = PP_ETHTOOL_RECYCLE_CACHE_FULL,
> +			.name = "rx_pp_recycle_cache_full"
> +		}, {
> +			.type = PP_ETHTOOL_RECYCLE_RING,
> +			.name = "rx_pp_recycle_ring"
> +		}, {
> +			.type = PP_ETHTOOL_RECYCLE_RING_FULL,
> +			.name = "rx_pp_recycle_ring_full"
> +		}, {
> +			.type = PP_ETHTOOL_RECYCLE_RELEASED_REF,
> +			.name = "rx_pp_recycle_released_ref"
> +		},
> +	};
> +	int i;
> +
> +	for (i = 0; i < PP_ETHTOOL_STATS_MAX; i++) {
> +		memcpy(data, stats[i].name, ETH_GSTRING_LEN);
> +		data += ETH_GSTRING_LEN;
> +	}

Re: [RFC net-next 1/2] net: page_pool: introduce ethtool stats

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 1833 bytes --]

On Apr 07, Jakub Kicinski wrote:
> On Thu,  7 Apr 2022 18:55:04 +0200 Lorenzo Bianconi wrote:
> > +void page_pool_ethtool_stats_get_strings(u8 *data)
> 
> This needs to return the pointer to after the used area, so drivers can
> append more stats. Or make data double pointer and update it before
> returning.

ack, I will fix it in v2.

> 
> > +{
> > +	static const struct {
> > +		u8 type;
> > +		char name[ETH_GSTRING_LEN];
> > +	} stats[PP_ETHTOOL_STATS_MAX] = {
> > +		{
> > +			.type = PP_ETHTOOL_ALLOC_FAST,
> 
> Why enumerate the type? It's not used.

ack, I will fix it in v2.

Regards,
Lorenzo
> 
> > +			.name = "rx_pp_alloc_fast"
> > +		}, {
> > +			.type = PP_ETHTOOL_ALLOC_SLOW,
> > +			.name = "rx_pp_alloc_slow"
> > +		}, {
> > +			.type = PP_ETHTOOL_ALLOC_SLOW_HIGH_ORDER,
> > +			.name = "rx_pp_alloc_slow_ho"
> > +		}, {
> > +			.type = PP_ETHTOOL_ALLOC_EMPTY,
> > +			.name = "rx_pp_alloc_empty"
> > +		}, {
> > +			.type = PP_ETHTOOL_ALLOC_REFILL,
> > +			.name = "rx_pp_alloc_refill"
> > +		}, {
> > +			.type = PP_ETHTOOL_ALLOC_WAIVE,
> > +			.name = "rx_pp_alloc_waive"
> > +		}, {
> > +			.type = PP_ETHTOOL_RECYCLE_CACHED,
> > +			.name = "rx_pp_recycle_cached"
> > +		}, {
> > +			.type = PP_ETHTOOL_RECYCLE_CACHE_FULL,
> > +			.name = "rx_pp_recycle_cache_full"
> > +		}, {
> > +			.type = PP_ETHTOOL_RECYCLE_RING,
> > +			.name = "rx_pp_recycle_ring"
> > +		}, {
> > +			.type = PP_ETHTOOL_RECYCLE_RING_FULL,
> > +			.name = "rx_pp_recycle_ring_full"
> > +		}, {
> > +			.type = PP_ETHTOOL_RECYCLE_RELEASED_REF,
> > +			.name = "rx_pp_recycle_released_ref"
> > +		},
> > +	};
> > +	int i;
> > +
> > +	for (i = 0; i < PP_ETHTOOL_STATS_MAX; i++) {
> > +		memcpy(data, stats[i].name, ETH_GSTRING_LEN);
> > +		data += ETH_GSTRING_LEN;
> > +	}

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[RFC net-next 2/2] net: mvneta: add support for page_pool_get_stats

[Lorenzo Bianconi]

Introduce support for the page_pool_get_stats API to mvneta driver.
Report page_pool stats through ethtool.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/Kconfig  |  1 +
 drivers/net/ethernet/marvell/mvneta.c | 59 ++++++++++++++++++++++++---
 2 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/marvell/Kconfig b/drivers/net/ethernet/marvell/Kconfig
index fe0989c0fc25..1240cb2dc07f 100644
--- a/drivers/net/ethernet/marvell/Kconfig
+++ b/drivers/net/ethernet/marvell/Kconfig
@@ -62,6 +62,7 @@ config MVNETA
 	select MVMDIO
 	select PHYLINK
 	select PAGE_POOL
+	select PAGE_POOL_STATS
 	help
 	  This driver supports the network interface units in the
 	  Marvell ARMADA XP, ARMADA 370, ARMADA 38x and
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 934f6dd90992..9864ea09e887 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -540,7 +540,7 @@ struct mvneta_port {
 	bool eee_active;
 	bool tx_lpi_enabled;
 
-	u64 ethtool_stats[ARRAY_SIZE(mvneta_statistics)];
+	u64 *ethtool_stats;
 
 	u32 indir[MVNETA_RSS_LU_TABLE_SIZE];
 
@@ -4732,9 +4732,13 @@ static void mvneta_ethtool_get_strings(struct net_device *netdev, u32 sset,
 	if (sset == ETH_SS_STATS) {
 		int i;
 
-		for (i = 0; i < ARRAY_SIZE(mvneta_statistics); i++)
-			memcpy(data + i * ETH_GSTRING_LEN,
-			       mvneta_statistics[i].name, ETH_GSTRING_LEN);
+		for (i = 0; i < ARRAY_SIZE(mvneta_statistics); i++) {
+			memcpy(data, mvneta_statistics[i].name,
+			       ETH_GSTRING_LEN);
+			data += ETH_GSTRING_LEN;
+		}
+
+		page_pool_ethtool_stats_get_strings(data);
 	}
 }
 
@@ -4847,6 +4851,38 @@ static void mvneta_ethtool_update_stats(struct mvneta_port *pp)
 	}
 }
 
+static void mvneta_ethtool_pp_stats(struct mvneta_port *pp, u64 *data)
+{
+	struct page_pool_stats stats = {};
+	int i;
+
+	for (i = 0; i < rxq_number; i++) {
+		struct page_pool *page_pool = pp->rxqs[i].page_pool;
+		struct page_pool_stats pp_stats = {};
+
+		if (!page_pool_get_stats(page_pool, &pp_stats))
+			continue;
+
+		stats.alloc_stats.fast += pp_stats.alloc_stats.fast;
+		stats.alloc_stats.slow += pp_stats.alloc_stats.slow;
+		stats.alloc_stats.slow_high_order +=
+			pp_stats.alloc_stats.slow_high_order;
+		stats.alloc_stats.empty += pp_stats.alloc_stats.empty;
+		stats.alloc_stats.refill += pp_stats.alloc_stats.refill;
+		stats.alloc_stats.waive += pp_stats.alloc_stats.waive;
+		stats.recycle_stats.cached += pp_stats.recycle_stats.cached;
+		stats.recycle_stats.cache_full +=
+			pp_stats.recycle_stats.cache_full;
+		stats.recycle_stats.ring += pp_stats.recycle_stats.ring;
+		stats.recycle_stats.ring_full +=
+			pp_stats.recycle_stats.ring_full;
+		stats.recycle_stats.released_refcnt +=
+			pp_stats.recycle_stats.released_refcnt;
+	}
+
+	page_pool_ethtool_stats_get(data, &stats);
+}
+
 static void mvneta_ethtool_get_stats(struct net_device *dev,
 				     struct ethtool_stats *stats, u64 *data)
 {
@@ -4857,12 +4893,16 @@ static void mvneta_ethtool_get_stats(struct net_device *dev,
 
 	for (i = 0; i < ARRAY_SIZE(mvneta_statistics); i++)
 		*data++ = pp->ethtool_stats[i];
+
+	mvneta_ethtool_pp_stats(pp, data);
 }
 
 static int mvneta_ethtool_get_sset_count(struct net_device *dev, int sset)
 {
 	if (sset == ETH_SS_STATS)
-		return ARRAY_SIZE(mvneta_statistics);
+		return ARRAY_SIZE(mvneta_statistics) +
+		       page_pool_ethtool_stats_get_count();
+
 	return -EOPNOTSUPP;
 }
 
@@ -5372,6 +5412,7 @@ static int mvneta_probe(struct platform_device *pdev)
 	phy_interface_t phy_mode;
 	const char *mac_from;
 	int tx_csum_limit;
+	int stats_len;
 	int err;
 	int cpu;
 
@@ -5392,6 +5433,14 @@ static int mvneta_probe(struct platform_device *pdev)
 	pp->rxq_def = rxq_def;
 	pp->indir[0] = rxq_def;
 
+	stats_len = ARRAY_SIZE(mvneta_statistics) +
+		    page_pool_ethtool_stats_get_count();
+	pp->ethtool_stats = devm_kzalloc(&pdev->dev,
+					 sizeof(*pp->ethtool_stats) * stats_len,
+					 GFP_KERNEL);
+	if (!pp->ethtool_stats)
+		return -ENOMEM;
+
 	err = of_get_phy_mode(dn, &phy_mode);
 	if (err) {
 		dev_err(&pdev->dev, "incorrect phy-mode\n");
-- 
2.35.1

Re: [RFC net-next 2/2] net: mvneta: add support for page_pool_get_stats

[Andrew Lunn]

> +static void mvneta_ethtool_pp_stats(struct mvneta_port *pp, u64 *data)
> +{
> +	struct page_pool_stats stats = {};
> +	int i;
> +
> +	for (i = 0; i < rxq_number; i++) {
> +		struct page_pool *page_pool = pp->rxqs[i].page_pool;
> +		struct page_pool_stats pp_stats = {};
> +
> +		if (!page_pool_get_stats(page_pool, &pp_stats))
> +			continue;
> +
> +		stats.alloc_stats.fast += pp_stats.alloc_stats.fast;
> +		stats.alloc_stats.slow += pp_stats.alloc_stats.slow;
> +		stats.alloc_stats.slow_high_order +=
> +			pp_stats.alloc_stats.slow_high_order;
> +		stats.alloc_stats.empty += pp_stats.alloc_stats.empty;
> +		stats.alloc_stats.refill += pp_stats.alloc_stats.refill;
> +		stats.alloc_stats.waive += pp_stats.alloc_stats.waive;
> +		stats.recycle_stats.cached += pp_stats.recycle_stats.cached;
> +		stats.recycle_stats.cache_full +=
> +			pp_stats.recycle_stats.cache_full;
> +		stats.recycle_stats.ring += pp_stats.recycle_stats.ring;
> +		stats.recycle_stats.ring_full +=
> +			pp_stats.recycle_stats.ring_full;
> +		stats.recycle_stats.released_refcnt +=
> +			pp_stats.recycle_stats.released_refcnt;

We should be trying to remove this sort of code from the driver, and
put it all in the core.  It wants to be something more like:

	struct page_pool_stats stats = {};
	int i;

	for (i = 0; i < rxq_number; i++) {
		struct page_pool *page_pool = pp->rxqs[i].page_pool;

		if (!page_pool_get_stats(page_pool, &stats))
			continue;

	page_pool_ethtool_stats_get(data, &stats);

Let page_pool_get_stats() do the accumulate as it puts values in stats.

You probably should also rework the mellanox driver to use the same
code structure.

    Andrew

    

Re: [RFC net-next 2/2] net: mvneta: add support for page_pool_get_stats

[Ilias Apalodimas]

Hi Andrew,

On Thu, 7 Apr 2022 at 21:25, Andrew Lunn <andrew@lunn.ch> wrote:
>
> > +static void mvneta_ethtool_pp_stats(struct mvneta_port *pp, u64 *data)
> > +{
> > +     struct page_pool_stats stats = {};
> > +     int i;
> > +
> > +     for (i = 0; i < rxq_number; i++) {
> > +             struct page_pool *page_pool = pp->rxqs[i].page_pool;
> > +             struct page_pool_stats pp_stats = {};
> > +
> > +             if (!page_pool_get_stats(page_pool, &pp_stats))
> > +                     continue;
> > +
> > +             stats.alloc_stats.fast += pp_stats.alloc_stats.fast;
> > +             stats.alloc_stats.slow += pp_stats.alloc_stats.slow;
> > +             stats.alloc_stats.slow_high_order +=
> > +                     pp_stats.alloc_stats.slow_high_order;
> > +             stats.alloc_stats.empty += pp_stats.alloc_stats.empty;
> > +             stats.alloc_stats.refill += pp_stats.alloc_stats.refill;
> > +             stats.alloc_stats.waive += pp_stats.alloc_stats.waive;
> > +             stats.recycle_stats.cached += pp_stats.recycle_stats.cached;
> > +             stats.recycle_stats.cache_full +=
> > +                     pp_stats.recycle_stats.cache_full;
> > +             stats.recycle_stats.ring += pp_stats.recycle_stats.ring;
> > +             stats.recycle_stats.ring_full +=
> > +                     pp_stats.recycle_stats.ring_full;
> > +             stats.recycle_stats.released_refcnt +=
> > +                     pp_stats.recycle_stats.released_refcnt;
>
> We should be trying to remove this sort of code from the driver, and
> put it all in the core.  It wants to be something more like:
>
>         struct page_pool_stats stats = {};
>         int i;
>
>         for (i = 0; i < rxq_number; i++) {
>                 struct page_pool *page_pool = pp->rxqs[i].page_pool;
>
>                 if (!page_pool_get_stats(page_pool, &stats))
>                         continue;
>
>         page_pool_ethtool_stats_get(data, &stats);
>
> Let page_pool_get_stats() do the accumulate as it puts values in stats.

Unless I misunderstand this, I don't think that's doable in page pool.
That means page pool is aware of what stats to accumulate per driver
and I certainly don't want anything driver specific to creep in there.
The driver knows the number of pools he is using and he can gather
them all together.

Regards
/Ilias
>
> You probably should also rework the mellanox driver to use the same
> code structure.
>
>     Andrew
>
>

Re: [RFC net-next 2/2] net: mvneta: add support for page_pool_get_stats

[Andrew Lunn]

On Thu, Apr 07, 2022 at 09:35:52PM +0300, Ilias Apalodimas wrote:
> Hi Andrew,
> 
> On Thu, 7 Apr 2022 at 21:25, Andrew Lunn <andrew@lunn.ch> wrote:
> >
> > > +static void mvneta_ethtool_pp_stats(struct mvneta_port *pp, u64 *data)
> > > +{
> > > +     struct page_pool_stats stats = {};
> > > +     int i;
> > > +
> > > +     for (i = 0; i < rxq_number; i++) {
> > > +             struct page_pool *page_pool = pp->rxqs[i].page_pool;
> > > +             struct page_pool_stats pp_stats = {};
> > > +
> > > +             if (!page_pool_get_stats(page_pool, &pp_stats))
> > > +                     continue;
> > > +
> > > +             stats.alloc_stats.fast += pp_stats.alloc_stats.fast;
> > > +             stats.alloc_stats.slow += pp_stats.alloc_stats.slow;
> > > +             stats.alloc_stats.slow_high_order +=
> > > +                     pp_stats.alloc_stats.slow_high_order;
> > > +             stats.alloc_stats.empty += pp_stats.alloc_stats.empty;
> > > +             stats.alloc_stats.refill += pp_stats.alloc_stats.refill;
> > > +             stats.alloc_stats.waive += pp_stats.alloc_stats.waive;
> > > +             stats.recycle_stats.cached += pp_stats.recycle_stats.cached;
> > > +             stats.recycle_stats.cache_full +=
> > > +                     pp_stats.recycle_stats.cache_full;
> > > +             stats.recycle_stats.ring += pp_stats.recycle_stats.ring;
> > > +             stats.recycle_stats.ring_full +=
> > > +                     pp_stats.recycle_stats.ring_full;
> > > +             stats.recycle_stats.released_refcnt +=
> > > +                     pp_stats.recycle_stats.released_refcnt;
> >
> > We should be trying to remove this sort of code from the driver, and
> > put it all in the core.  It wants to be something more like:
> >
> >         struct page_pool_stats stats = {};
> >         int i;
> >
> >         for (i = 0; i < rxq_number; i++) {
> >                 struct page_pool *page_pool = pp->rxqs[i].page_pool;
> >
> >                 if (!page_pool_get_stats(page_pool, &stats))
> >                         continue;
> >
> >         page_pool_ethtool_stats_get(data, &stats);
> >
> > Let page_pool_get_stats() do the accumulate as it puts values in stats.
> 
> Unless I misunderstand this, I don't think that's doable in page pool.
> That means page pool is aware of what stats to accumulate per driver
> and I certainly don't want anything driver specific to creep in there.
> The driver knows the number of pools he is using and he can gather
> them all together.

I agree that the driver knows about the number of pools. For mvneta,
there is one per RX queue. Which is this part of my suggestion

> >         for (i = 0; i < rxq_number; i++) {
> >                 struct page_pool *page_pool = pp->rxqs[i].page_pool;
> >

However, it has no idea about the stats themselves. They are purely a
construct of the page pool. Hence the next part of my suggest, ask the
page pool for the stats, place them into stats, doing the accumulate
at the same time.:

> >                 if (!page_pool_get_stats(page_pool, &stats))
> >                         continue;

and now we have the accumulated stats, turn them into ethtool format:

> >         page_pool_ethtool_stats_get(data, &stats);

Where do you see any driver knowledge required in either of
page_pool_get_stats() or page_pool_ethtool_stats_get().

      Andrew

Re: [RFC net-next 2/2] net: mvneta: add support for page_pool_get_stats

[Ilias Apalodimas]

Hi Andrew,

[...]

> > > > +
> > > > +             stats.alloc_stats.fast += pp_stats.alloc_stats.fast;
> > > > +             stats.alloc_stats.slow += pp_stats.alloc_stats.slow;
> > > > +             stats.alloc_stats.slow_high_order +=
> > > > +                     pp_stats.alloc_stats.slow_high_order;
> > > > +             stats.alloc_stats.empty += pp_stats.alloc_stats.empty;
> > > > +             stats.alloc_stats.refill += pp_stats.alloc_stats.refill;
> > > > +             stats.alloc_stats.waive += pp_stats.alloc_stats.waive;
> > > > +             stats.recycle_stats.cached += pp_stats.recycle_stats.cached;
> > > > +             stats.recycle_stats.cache_full +=
> > > > +                     pp_stats.recycle_stats.cache_full;
> > > > +             stats.recycle_stats.ring += pp_stats.recycle_stats.ring;
> > > > +             stats.recycle_stats.ring_full +=
> > > > +                     pp_stats.recycle_stats.ring_full;
> > > > +             stats.recycle_stats.released_refcnt +=
> > > > +                     pp_stats.recycle_stats.released_refcnt;
> > >
> > > We should be trying to remove this sort of code from the driver, and
> > > put it all in the core.  It wants to be something more like:
> > >
> > >         struct page_pool_stats stats = {};
> > >         int i;
> > >
> > >         for (i = 0; i < rxq_number; i++) {
> > >                 struct page_pool *page_pool = pp->rxqs[i].page_pool;
> > >
> > >                 if (!page_pool_get_stats(page_pool, &stats))
> > >                         continue;
> > >
> > >         page_pool_ethtool_stats_get(data, &stats);
> > >
> > > Let page_pool_get_stats() do the accumulate as it puts values in stats.
> >
> > Unless I misunderstand this, I don't think that's doable in page pool.
> > That means page pool is aware of what stats to accumulate per driver
> > and I certainly don't want anything driver specific to creep in there.
> > The driver knows the number of pools he is using and he can gather
> > them all together.
>
> I agree that the driver knows about the number of pools. For mvneta,
> there is one per RX queue. Which is this part of my suggestion
>
> > >         for (i = 0; i < rxq_number; i++) {
> > >                 struct page_pool *page_pool = pp->rxqs[i].page_pool;
> > >
>
> However, it has no idea about the stats themselves. They are purely a
> construct of the page pool. Hence the next part of my suggest, ask the
> page pool for the stats, place them into stats, doing the accumulate
> at the same time.:
>
> > >                 if (!page_pool_get_stats(page_pool, &stats))
> > >                         continue;
>
> and now we have the accumulated stats, turn them into ethtool format:
>
> > >         page_pool_ethtool_stats_get(data, &stats);
>
> Where do you see any driver knowledge required in either of
> page_pool_get_stats() or page_pool_ethtool_stats_get().

Indeed I read the first mail wrong. I thought you wanted page_pool it
self to account for the driver stats without passing a 'struct
page_pool *pool' to page_pool_get_stats(). In a system with XDP (which
also uses page_pool) or multiple drivers using that, it would require
some metadata fed into the page pool subsystem to reason about which
pools to accumulate.

The code snip you included seems fine.

Thanks
/Ilias

>
>       Andrew