Commit b91fec1e authored by Benjamin Poirier's avatar Benjamin Poirier Committed by Greg Kroah-Hartman
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staging: qlge: Refill empty buffer queues from wq 



When operating at mtu 9000, qlge does order-1 allocations for rx buffers in
atomic context. This is especially unreliable when free memory is low or
fragmented. Add an approach similar to commit 3161e453 ("virtio: net
refill on out-of-memory") to qlge so that the device doesn't lock up if
there are allocation failures.

Signed-off-by: default avatarBenjamin Poirier <bpoirier@suse.com>
Link: https://lore.kernel.org/r/20190927101210.23856-18-bpoirier@suse.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6e9c52b9

drivers/staging/qlge/TODO

+0 −3
Original line number Diff line number Diff line 
* reception stalls permanently (until admin intervention) if the rx buffer

  queues become empty because of allocation failures (ex. under memory

  pressure)

* commit 7c734359d350 ("qlge: Size RX buffers based on MTU.", v2.6.33-rc1)

  introduced dead code in the receive routines, which should be rewritten

  anyways by the admission of the author himself, see the comment above

drivers/staging/qlge/qlge.h

+8 −0
Original line number Diff line number Diff line
@@ -1452,6 +1452,13 @@ struct qlge_bq { 


#define QLGE_BQ_WRAP(index) ((index) & (QLGE_BQ_LEN - 1))



#define QLGE_BQ_HW_OWNED(bq) \

({ \

	typeof(bq) _bq = bq; \

	QLGE_BQ_WRAP(QLGE_BQ_ALIGN((_bq)->next_to_use) - \

		     (_bq)->next_to_clean); \

})



struct rx_ring {

	struct cqicb cqicb;	/* The chip's completion queue init control block. */
@@ -1479,6 +1486,7 @@ struct rx_ring { 
	/* Misc. handler elements. */

	u32 irq;		/* Which vector this ring is assigned. */

	u32 cpu;		/* Which CPU this should run on. */

	struct delayed_work refill_work;

	char name[IFNAMSIZ + 5];

	struct napi_struct napi;

	u8 reserved;

drivers/staging/qlge/qlge_main.c

+64 −16
Original line number Diff line number Diff line
@@ -1029,7 +1029,7 @@ static const char * const bq_type_name[] = { 


/* return 0 or negative error */

static int qlge_refill_sb(struct rx_ring *rx_ring,

			  struct qlge_bq_desc *sbq_desc)

			  struct qlge_bq_desc *sbq_desc, gfp_t gfp)

{

	struct ql_adapter *qdev = rx_ring->qdev;

	struct sk_buff *skb;
@@ -1041,7 +1041,7 @@ static int qlge_refill_sb(struct rx_ring *rx_ring, 
		     "ring %u sbq: getting new skb for index %d.\n",

		     rx_ring->cq_id, sbq_desc->index);



	skb = netdev_alloc_skb(qdev->ndev, SMALL_BUFFER_SIZE);

	skb = __netdev_alloc_skb(qdev->ndev, SMALL_BUFFER_SIZE, gfp);

	if (!skb)

		return -ENOMEM;

	skb_reserve(skb, QLGE_SB_PAD);
@@ -1062,7 +1062,7 @@ static int qlge_refill_sb(struct rx_ring *rx_ring, 


/* return 0 or negative error */

static int qlge_refill_lb(struct rx_ring *rx_ring,

			  struct qlge_bq_desc *lbq_desc)

			  struct qlge_bq_desc *lbq_desc, gfp_t gfp)

{

	struct ql_adapter *qdev = rx_ring->qdev;

	struct qlge_page_chunk *master_chunk = &rx_ring->master_chunk;
@@ -1071,8 +1071,7 @@ static int qlge_refill_lb(struct rx_ring *rx_ring, 
		struct page *page;

		dma_addr_t dma_addr;



		page = alloc_pages(__GFP_COMP | GFP_ATOMIC,

				   qdev->lbq_buf_order);

		page = alloc_pages(gfp | __GFP_COMP, qdev->lbq_buf_order);

		if (unlikely(!page))

			return -ENOMEM;

		dma_addr = pci_map_page(qdev->pdev, page, 0,
@@ -1109,33 +1108,33 @@ static int qlge_refill_lb(struct rx_ring *rx_ring, 
	return 0;

}



static void qlge_refill_bq(struct qlge_bq *bq)

/* return 0 or negative error */

static int qlge_refill_bq(struct qlge_bq *bq, gfp_t gfp)

{

	struct rx_ring *rx_ring = QLGE_BQ_CONTAINER(bq);

	struct ql_adapter *qdev = rx_ring->qdev;

	struct qlge_bq_desc *bq_desc;

	int refill_count;

	int retval;

	int i;



	refill_count = QLGE_BQ_WRAP(QLGE_BQ_ALIGN(bq->next_to_clean - 1) -

				    bq->next_to_use);

	if (!refill_count)

		return;

		return 0;



	i = bq->next_to_use;

	bq_desc = &bq->queue[i];

	i -= QLGE_BQ_LEN;

	do {

		int retval;



		netif_printk(qdev, rx_status, KERN_DEBUG, qdev->ndev,

			     "ring %u %s: try cleaning idx %d\n",

			     rx_ring->cq_id, bq_type_name[bq->type], i);



		if (bq->type == QLGE_SB)

			retval = qlge_refill_sb(rx_ring, bq_desc);

			retval = qlge_refill_sb(rx_ring, bq_desc, gfp);

		else

			retval = qlge_refill_lb(rx_ring, bq_desc);

			retval = qlge_refill_lb(rx_ring, bq_desc, gfp);

		if (retval < 0) {

			netif_err(qdev, ifup, qdev->ndev,

				  "ring %u %s: Could not get a page chunk, idx %d\n",
@@ -1163,12 +1162,52 @@ static void qlge_refill_bq(struct qlge_bq *bq) 
		}

		bq->next_to_use = i;

	}



	return retval;

}



static void ql_update_buffer_queues(struct rx_ring *rx_ring, gfp_t gfp,

				    unsigned long delay)

{

	bool sbq_fail, lbq_fail;



	sbq_fail = !!qlge_refill_bq(&rx_ring->sbq, gfp);

	lbq_fail = !!qlge_refill_bq(&rx_ring->lbq, gfp);



	/* Minimum number of buffers needed to be able to receive at least one

	 * frame of any format:

	 * sbq: 1 for header + 1 for data

	 * lbq: mtu 9000 / lb size

	 * Below this, the queue might stall.

	 */

	if ((sbq_fail && QLGE_BQ_HW_OWNED(&rx_ring->sbq) < 2) ||

	    (lbq_fail && QLGE_BQ_HW_OWNED(&rx_ring->lbq) <

	     DIV_ROUND_UP(9000, LARGE_BUFFER_MAX_SIZE)))

		/* Allocations can take a long time in certain cases (ex.

		 * reclaim). Therefore, use a workqueue for long-running

		 * work items.

		 */

		queue_delayed_work_on(smp_processor_id(), system_long_wq,

				      &rx_ring->refill_work, delay);

}



static void ql_update_buffer_queues(struct rx_ring *rx_ring)

static void qlge_slow_refill(struct work_struct *work)

{

	qlge_refill_bq(&rx_ring->sbq);

	qlge_refill_bq(&rx_ring->lbq);

	struct rx_ring *rx_ring = container_of(work, struct rx_ring,

					       refill_work.work);

	struct napi_struct *napi = &rx_ring->napi;



	napi_disable(napi);

	ql_update_buffer_queues(rx_ring, GFP_KERNEL, HZ / 2);

	napi_enable(napi);



	local_bh_disable();

	/* napi_disable() might have prevented incomplete napi work from being

	 * rescheduled.

	 */

	napi_schedule(napi);

	/* trigger softirq processing */

	local_bh_enable();

}



/* Unmaps tx buffers.  Can be called from send() if a pci mapping
@@ -2168,7 +2207,7 @@ static int ql_clean_inbound_rx_ring(struct rx_ring *rx_ring, int budget) 
		if (count == budget)

			break;

	}

	ql_update_buffer_queues(rx_ring);

	ql_update_buffer_queues(rx_ring, GFP_ATOMIC, 0);

	ql_write_cq_idx(rx_ring);

	return count;

}
@@ -2778,7 +2817,8 @@ static void ql_alloc_rx_buffers(struct ql_adapter *qdev) 
	int i;



	for (i = 0; i < qdev->rss_ring_count; i++)

		ql_update_buffer_queues(&qdev->rx_ring[i]);

		ql_update_buffer_queues(&qdev->rx_ring[i], GFP_KERNEL,

					HZ / 2);

}



static int qlge_init_bq(struct qlge_bq *bq)
@@ -3883,6 +3923,7 @@ static int ql_get_adapter_resources(struct ql_adapter *qdev) 
static int qlge_close(struct net_device *ndev)

{

	struct ql_adapter *qdev = netdev_priv(ndev);

	int i;



	/* If we hit pci_channel_io_perm_failure

	 * failure condition, then we already
@@ -3900,6 +3941,11 @@ static int qlge_close(struct net_device *ndev) 
	 */

	while (!test_bit(QL_ADAPTER_UP, &qdev->flags))

		msleep(1);



	/* Make sure refill_work doesn't re-enable napi */

	for (i = 0; i < qdev->rss_ring_count; i++)

		cancel_delayed_work_sync(&qdev->rx_ring[i].refill_work);



	ql_adapter_down(qdev);

	ql_release_adapter_resources(qdev);

	return 0;
@@ -3966,6 +4012,8 @@ static int ql_configure_rings(struct ql_adapter *qdev) 
			    rx_ring->cq_len * sizeof(struct ql_net_rsp_iocb);

			rx_ring->lbq.type = QLGE_LB;

			rx_ring->sbq.type = QLGE_SB;

			INIT_DELAYED_WORK(&rx_ring->refill_work,

					  &qlge_slow_refill);

		} else {

			/*

			 * Outbound queue handles outbound completions only.