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Commit 60b778ce authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

rfs: better sizing of dev_flow_table 



Aim of this patch is to provide full range of rps_flow_cnt on 64bit arches.

Theorical limit on number of flows is 2^32

Fix some buggy RPS/RFS macros as well.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
CC: Xi Wang <xi.wang@gmail.com>
CC: Laurent Chavey <chavey@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 035c4c16

include/linux/netdevice.h

+4 −4
Original line number Diff line number Diff line
@@ -597,7 +597,7 @@ struct rps_map { 
	struct rcu_head rcu;

	u16 cpus[0];

};

#define RPS_MAP_SIZE(_num) (sizeof(struct rps_map) + (_num * sizeof(u16)))

#define RPS_MAP_SIZE(_num) (sizeof(struct rps_map) + ((_num) * sizeof(u16)))



/*

 * The rps_dev_flow structure contains the mapping of a flow to a CPU, the
@@ -621,7 +621,7 @@ struct rps_dev_flow_table { 
	struct rps_dev_flow flows[0];

};

#define RPS_DEV_FLOW_TABLE_SIZE(_num) (sizeof(struct rps_dev_flow_table) + \

    (_num * sizeof(struct rps_dev_flow)))

    ((_num) * sizeof(struct rps_dev_flow)))



/*

 * The rps_sock_flow_table contains mappings of flows to the last CPU
@@ -632,7 +632,7 @@ struct rps_sock_flow_table { 
	u16 ents[0];

};

#define	RPS_SOCK_FLOW_TABLE_SIZE(_num) (sizeof(struct rps_sock_flow_table) + \

    (_num * sizeof(u16)))

    ((_num) * sizeof(u16)))



#define RPS_NO_CPU 0xffff
@@ -684,7 +684,7 @@ struct xps_map { 
	struct rcu_head rcu;

	u16 queues[0];

};

#define XPS_MAP_SIZE(_num) (sizeof(struct xps_map) + (_num * sizeof(u16)))

#define XPS_MAP_SIZE(_num) (sizeof(struct xps_map) + ((_num) * sizeof(u16)))

#define XPS_MIN_MAP_ALLOC ((L1_CACHE_BYTES - sizeof(struct xps_map))	\

    / sizeof(u16))

net/core/net-sysfs.c

+27 −17
Original line number Diff line number Diff line
@@ -622,15 +622,15 @@ static ssize_t show_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue, 
					   char *buf)

{

	struct rps_dev_flow_table *flow_table;

	unsigned int val = 0;

	unsigned long val = 0;



	rcu_read_lock();

	flow_table = rcu_dereference(queue->rps_flow_table);

	if (flow_table)

		val = flow_table->mask + 1;

		val = (unsigned long)flow_table->mask + 1;

	rcu_read_unlock();



	return sprintf(buf, "%u\n", val);

	return sprintf(buf, "%lu\n", val);

}



static void rps_dev_flow_table_release_work(struct work_struct *work)
@@ -654,36 +654,46 @@ static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue, 
				     struct rx_queue_attribute *attr,

				     const char *buf, size_t len)

{

	unsigned int count;

	char *endp;

	unsigned long mask, count;

	struct rps_dev_flow_table *table, *old_table;

	static DEFINE_SPINLOCK(rps_dev_flow_lock);

	int rc;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	count = simple_strtoul(buf, &endp, 0);

	if (endp == buf)

		return -EINVAL;

	rc = kstrtoul(buf, 0, &count);

	if (rc < 0)

		return rc;



	if (count) {

		int i;



		if (count > INT_MAX)

		mask = count - 1;

		/* mask = roundup_pow_of_two(count) - 1;

		 * without overflows...

		 */

		while ((mask | (mask >> 1)) != mask)

			mask |= (mask >> 1);

		/* On 64 bit arches, must check mask fits in table->mask (u32),

		 * and on 32bit arches, must check RPS_DEV_FLOW_TABLE_SIZE(mask + 1)

		 * doesnt overflow.

		 */

#if BITS_PER_LONG > 32

		if (mask > (unsigned long)(u32)mask)

			return -EINVAL;

		count = roundup_pow_of_two(count);

		if (count > (ULONG_MAX - sizeof(struct rps_dev_flow_table))

#else

		if (mask > (ULONG_MAX - RPS_DEV_FLOW_TABLE_SIZE(1))

				/ sizeof(struct rps_dev_flow)) {

			/* Enforce a limit to prevent overflow */

			return -EINVAL;

		}

		table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));

#endif

		table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(mask + 1));

		if (!table)

			return -ENOMEM;



		table->mask = count - 1;

		for (i = 0; i < count; i++)

			table->flows[i].cpu = RPS_NO_CPU;

		table->mask = mask;

		for (count = 0; count <= mask; count++)

			table->flows[count].cpu = RPS_NO_CPU;

	} else

		table = NULL;