Commit 43a335e0 authored by Amir Vadai's avatar Amir Vadai Committed by David S. Miller
Browse files

net/mlx5_core: Flow counters infrastructure 



If a counter has the aging flag set when created, it is added to a list
of counters that will be queried periodically from a workqueue.  query
result and last use timestamp are cached.
add/del counter must be very efficient since thousands of such
operations might be issued in a second.
There is only a single reference to counters without aging, therefore
no need for locks.
But, counters with aging enabled are stored in a list. In order to make
code as lockless as possible, all the list manipulation and access to
hardware is done from a single context - the periodic counters query
thread.

The hardware supports multiple counters per FTE, however currently we
are using one counter for each FTE.

Signed-off-by: default avatarAmir Vadai <amirva@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bd5251db

drivers/net/ethernet/mellanox/mlx5/core/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ obj-$(CONFIG_MLX5_CORE) += mlx5_core.o 


mlx5_core-y :=	main.o cmd.o debugfs.o fw.o eq.o uar.o pagealloc.o \

		health.o mcg.o cq.o srq.o alloc.o qp.o port.o mr.o pd.o   \

		mad.o transobj.o vport.o sriov.o fs_cmd.o fs_core.o

		mad.o transobj.o vport.o sriov.o fs_cmd.o fs_core.o fs_counters.o



mlx5_core-$(CONFIG_MLX5_CORE_EN) += wq.o eswitch.o \

		en_main.o en_fs.o en_ethtool.o en_tx.o en_rx.o \

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

+6 −1
Original line number Diff line number Diff line
@@ -1771,6 +1771,7 @@ void mlx5_cleanup_fs(struct mlx5_core_dev *dev) 
	cleanup_single_prio_root_ns(dev, dev->priv.fdb_root_ns);

	cleanup_single_prio_root_ns(dev, dev->priv.esw_egress_root_ns);

	cleanup_single_prio_root_ns(dev, dev->priv.esw_ingress_root_ns);

	mlx5_cleanup_fc_stats(dev);

}



static int init_fdb_root_ns(struct mlx5_core_dev *dev)
@@ -1827,10 +1828,14 @@ int mlx5_init_fs(struct mlx5_core_dev *dev) 
{

	int err = 0;



	err = mlx5_init_fc_stats(dev);

	if (err)

		return err;



	if (MLX5_CAP_GEN(dev, nic_flow_table)) {

		err = init_root_ns(dev);

		if (err)

			return err;

			goto err;

	}

	if (MLX5_CAP_GEN(dev, eswitch_flow_table)) {

		err = init_fdb_root_ns(dev);

drivers/net/ethernet/mellanox/mlx5/core/fs_core.h

+3 −0
Original line number Diff line number Diff line
@@ -169,6 +169,9 @@ struct mlx5_flow_root_namespace { 
	struct mutex			chain_lock;

};



int mlx5_init_fc_stats(struct mlx5_core_dev *dev);

void mlx5_cleanup_fc_stats(struct mlx5_core_dev *dev);



int mlx5_init_fs(struct mlx5_core_dev *dev);

void mlx5_cleanup_fs(struct mlx5_core_dev *dev);

drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c

0 → 100644
+226 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2016, Mellanox Technologies. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the

 * OpenIB.org BSD license below:

 *

 *     Redistribution and use in source and binary forms, with or

 *     without modification, are permitted provided that the following

 *     conditions are met:

 *

 *      - Redistributions of source code must retain the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer.

 *

 *      - Redistributions in binary form must reproduce the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer in the documentation and/or other materials

 *        provided with the distribution.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */



#include <linux/mlx5/driver.h>

#include <linux/mlx5/fs.h>

#include "mlx5_core.h"

#include "fs_core.h"

#include "fs_cmd.h"



#define MLX5_FC_STATS_PERIOD msecs_to_jiffies(1000)



/* locking scheme:

 *

 * It is the responsibility of the user to prevent concurrent calls or bad

 * ordering to mlx5_fc_create(), mlx5_fc_destroy() and accessing a reference

 * to struct mlx5_fc.

 * e.g en_tc.c is protected by RTNL lock of its caller, and will never call a

 * dump (access to struct mlx5_fc) after a counter is destroyed.

 *

 * access to counter list:

 * - create (user context)

 *   - mlx5_fc_create() only adds to an addlist to be used by

 *     mlx5_fc_stats_query_work(). addlist is protected by a spinlock.

 *   - spawn thread to do the actual destroy

 *

 * - destroy (user context)

 *   - mark a counter as deleted

 *   - spawn thread to do the actual del

 *

 * - dump (user context)

 *   user should not call dump after destroy

 *

 * - query (single thread workqueue context)

 *   destroy/dump - no conflict (see destroy)

 *   query/dump - packets and bytes might be inconsistent (since update is not

 *                atomic)

 *   query/create - no conflict (see create)

 *   since every create/destroy spawn the work, only after necessary time has

 *   elapsed, the thread will actually query the hardware.

 */



static void mlx5_fc_stats_work(struct work_struct *work)

{

	struct mlx5_core_dev *dev = container_of(work, struct mlx5_core_dev,

						 priv.fc_stats.work.work);

	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

	unsigned long now = jiffies;

	struct mlx5_fc *counter;

	struct mlx5_fc *tmp;

	int err = 0;



	spin_lock(&fc_stats->addlist_lock);



	list_splice_tail_init(&fc_stats->addlist, &fc_stats->list);



	if (!list_empty(&fc_stats->list))

		queue_delayed_work(fc_stats->wq, &fc_stats->work, MLX5_FC_STATS_PERIOD);



	spin_unlock(&fc_stats->addlist_lock);



	list_for_each_entry_safe(counter, tmp, &fc_stats->list, list) {

		struct mlx5_fc_cache *c = &counter->cache;

		u64 packets;

		u64 bytes;



		if (counter->deleted) {

			list_del(&counter->list);



			mlx5_cmd_fc_free(dev, counter->id);



			kfree(counter);

			continue;

		}



		if (time_before(now, fc_stats->next_query))

			continue;



		err = mlx5_cmd_fc_query(dev, counter->id, &packets, &bytes);

		if (err) {

			pr_err("Error querying stats for counter id %d\n",

			       counter->id);

			continue;

		}



		if (packets == c->packets)

			continue;



		c->lastuse = jiffies;

		c->packets = packets;

		c->bytes   = bytes;

	}



	if (time_after_eq(now, fc_stats->next_query))

		fc_stats->next_query = now + MLX5_FC_STATS_PERIOD;

}



struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging)

{

	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

	struct mlx5_fc *counter;

	int err;



	counter = kzalloc(sizeof(*counter), GFP_KERNEL);

	if (!counter)

		return ERR_PTR(-ENOMEM);



	err = mlx5_cmd_fc_alloc(dev, &counter->id);

	if (err)

		goto err_out;



	if (aging) {

		counter->aging = true;



		spin_lock(&fc_stats->addlist_lock);

		list_add(&counter->list, &fc_stats->addlist);

		spin_unlock(&fc_stats->addlist_lock);



		mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);

	}



	return counter;



err_out:

	kfree(counter);



	return ERR_PTR(err);

}



void mlx5_fc_destroy(struct mlx5_core_dev *dev, struct mlx5_fc *counter)

{

	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;



	if (!counter)

		return;



	if (counter->aging) {

		counter->deleted = true;

		mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);

		return;

	}



	mlx5_cmd_fc_free(dev, counter->id);

	kfree(counter);

}



int mlx5_init_fc_stats(struct mlx5_core_dev *dev)

{

	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;



	INIT_LIST_HEAD(&fc_stats->list);

	INIT_LIST_HEAD(&fc_stats->addlist);

	spin_lock_init(&fc_stats->addlist_lock);



	fc_stats->wq = create_singlethread_workqueue("mlx5_fc");

	if (!fc_stats->wq)

		return -ENOMEM;



	INIT_DELAYED_WORK(&fc_stats->work, mlx5_fc_stats_work);



	return 0;

}



void mlx5_cleanup_fc_stats(struct mlx5_core_dev *dev)

{

	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

	struct mlx5_fc *counter;

	struct mlx5_fc *tmp;



	cancel_delayed_work_sync(&dev->priv.fc_stats.work);

	destroy_workqueue(dev->priv.fc_stats.wq);

	dev->priv.fc_stats.wq = NULL;



	list_splice_tail_init(&fc_stats->addlist, &fc_stats->list);



	list_for_each_entry_safe(counter, tmp, &fc_stats->list, list) {

		list_del(&counter->list);



		mlx5_cmd_fc_free(dev, counter->id);



		kfree(counter);

	}

}



void mlx5_fc_query_cached(struct mlx5_fc *counter,

			  u64 *bytes, u64 *packets, u64 *lastuse)

{

	struct mlx5_fc_cache c;



	c = counter->cache;



	*bytes = c.bytes - counter->lastbytes;

	*packets = c.packets - counter->lastpackets;

	*lastuse = c.lastuse;



	counter->lastbytes = c.bytes;

	counter->lastpackets = c.packets;

}

include/linux/mlx5/driver.h

+14 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/radix-tree.h>

#include <linux/workqueue.h>



#include <linux/mlx5/device.h>

#include <linux/mlx5/doorbell.h>
@@ -457,6 +458,17 @@ struct mlx5_irq_info { 
	char name[MLX5_MAX_IRQ_NAME];

};



struct mlx5_fc_stats {

	struct list_head list;

	struct list_head addlist;

	/* protect addlist add/splice operations */

	spinlock_t addlist_lock;



	struct workqueue_struct *wq;

	struct delayed_work work;

	unsigned long next_query;

};



struct mlx5_eswitch;



struct mlx5_priv {
@@ -520,6 +532,8 @@ struct mlx5_priv { 
	struct mlx5_flow_root_namespace *fdb_root_ns;

	struct mlx5_flow_root_namespace *esw_egress_root_ns;

	struct mlx5_flow_root_namespace *esw_ingress_root_ns;



	struct mlx5_fc_stats		fc_stats;

};



enum mlx5_device_state {

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