[<prev] [next>] [day] [month] [year] [list]
Message-ID: <20140927182034.GA13698@oracle.com>
Date: Sat, 27 Sep 2014 11:20:34 -0700
From: Venkat Venkatsubra <venkat.x.venkatsubra@...cle.com>
To: netdev@...r.kernel.org, linux-rdma@...r.kernel.org
Cc: davem@...emloft.net, venkat.x.venkatsubra@...cle.com
Subject: [PATCH] IB/ipoib: order:1 failure in ipoib_cm_alloc_rx_skb causes
softlockup
In ipoib_cm_alloc_rx_skb
skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
results in order:1 allocation because IPOIB_CM_HEAD_SIZE is defined as:
IPOIB_ENCAP_LEN = 4,
IPOIB_CM_MTU = 0x10000 - 0x10, /* padding to align header to 16 */
IPOIB_CM_BUF_SIZE = IPOIB_CM_MTU + IPOIB_ENCAP_LEN,
IPOIB_CM_HEAD_SIZE = IPOIB_CM_BUF_SIZE % PAGE_SIZE,
For a 4Kbytes PAGE_SIZE IPOIB_CM_HEAD_SIZE ends up as
(65536 - 16 + 4) % 4096 = 4084 bytes resulting in
dev_alloc_skb(4084 + 12) or dev_alloc_skb(4096) or order:1 allocation.
This fix avoids this by redefining IPOIB_CM_HEAD_SIZE to whatever maximum
that can fit in a order:0 allocation and adjusting number of scatter/gather
elements to accommodate the rest of the bytes.
IPOIB_CM_RX_SG is incremented by 1 to accommodate one extra SG element.
Since using NET_SKB_PAD in IPOIB_CM_HEAD_SIZE now gives the below
compilation error due to max()
"braced-group within expression allowed only inside a function"
actual number of SG elements used is now computed in a variable.
Here is a stack trace of an order:1 failure:
kswapd0: page allocation failure. order:1, mode:0x20
Pid: 273, comm: kswapd0 Not tainted 2.6.32-400.11.1.el5uek #1
Call Trace:
<IRQ> [<ffffffff810ddf74>] __alloc_pages_nodemask+0x524/0x595
[<ffffffff8110da3f>] kmem_getpages+0x4f/0xf4
[<ffffffff8110dc3c>] fallback_alloc+0x158/0x1ce
[<ffffffff8110ddd3>] ____cache_alloc_node+0x121/0x134
[<ffffffff8110e3f3>] kmem_cache_alloc_node_notrace+0x84/0xb9
[<ffffffff8110e46e>] __kmalloc_node+0x46/0x73
[<ffffffff813b9aa8>] ? __alloc_skb+0x72/0x13d
[<ffffffff813b9aa8>] __alloc_skb+0x72/0x13d
[<ffffffff813b9bdb>] alloc_skb+0x13/0x15
[<ffffffff813b9f11>] dev_alloc_skb+0x1b/0x38
[<ffffffffa029e722>] ipoib_cm_alloc_rx_skb+0x31/0x1de [ib_ipoib]
[<ffffffffa029fd04>] ipoib_cm_handle_rx_wc+0x3a1/0x5b8 [ib_ipoib]
[<ffffffffa0191bdc>] ? mlx4_ib_free_srq_wqe+0x27/0x54 [mlx4_ib]
[<ffffffffa01894d4>] ? mlx4_ib_poll_cq+0x620/0x65e [mlx4_ib]
[<ffffffff813b9015>] ? __kfree_skb+0x79/0x7e
[<ffffffffa029e9f7>] ? netif_tx_lock+0x44/0x71 [ib_ipoib]
[<ffffffffa029ae97>] ipoib_poll+0x87/0x128 [ib_ipoib]
[<ffffffff813c4b69>] net_rx_action+0xc6/0x1cd
[<ffffffff8105e8cd>] __do_softirq+0xd7/0x19e
[<ffffffff810aefdc>] ? handle_IRQ_event+0x66/0x120
[<ffffffff81012eec>] call_softirq+0x1c/0x30
[<ffffffff81014695>] do_softirq+0x46/0x89
[<ffffffff8105e752>] irq_exit+0x3b/0x7a
[<ffffffff8145bea1>] do_IRQ+0x99/0xb0
[<ffffffff81012713>] ret_from_intr+0x0/0x11
<EOI> [<ffffffff812379a3>] ? radix_tree_delete+0x8f/0x194
[<ffffffffa03693b3>] ? __nfs_access_zap_cache+0x75/0xb0 [nfs]
[<ffffffff81207d05>] ? ima_inode_free+0x35/0x55
[<ffffffff8112fd9c>] ? __destroy_inode+0x26/0x66
[<ffffffff8112fdf2>] ? destroy_inode+0x16/0x44
[<ffffffff81130074>] ? dispose_list+0xb2/0xe1
[<ffffffff81130251>] ? shrink_icache_memory+0x1ae/0x1e0
[<ffffffff810e3f83>] ? shrink_slab+0xe1/0x153
[<ffffffff810e5063>] ? kswapd+0x3dd/0x516
[<ffffffff810e26f3>] ? isolate_pages_global+0x0/0x1ba
[<ffffffff810432be>] ? need_resched+0x23/0x2d
[<ffffffff81077030>] ? autoremove_wake_function+0x0/0x3d
[<ffffffff810e4c86>] ? kswapd+0x0/0x516
[<ffffffff81076c87>] ? kthread+0x6e/0x76
[<ffffffff81012dea>] ? child_rip+0xa/0x20
[<ffffffff81076c19>] ? kthread+0x0/0x76
[<ffffffff81012de0>] ? child_rip+0x0/0x20
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@...cle.com>
---
drivers/infiniband/ulp/ipoib/ipoib.h | 11 +++++++++--
drivers/infiniband/ulp/ipoib/ipoib_cm.c | 21 +++++++++++++--------
drivers/infiniband/ulp/ipoib/ipoib_main.c | 7 ++++++-
3 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 3edce61..e0b5a63 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -61,6 +61,11 @@ enum ipoib_flush_level {
IPOIB_FLUSH_HEAVY
};
+/* 12 bytes added to align the IP header to a multiple of 16 bytes
+ * after IPoIB adds 4 byte header.
+ */
+#define IPOIB_CM_HEAD_SIZE SKB_MAX_HEAD(NET_SKB_PAD + 12)
+
enum {
IPOIB_ENCAP_LEN = 4,
@@ -69,8 +74,8 @@ enum {
IPOIB_CM_MTU = 0x10000 - 0x10, /* padding to align header to 16 */
IPOIB_CM_BUF_SIZE = IPOIB_CM_MTU + IPOIB_ENCAP_LEN,
- IPOIB_CM_HEAD_SIZE = IPOIB_CM_BUF_SIZE % PAGE_SIZE,
- IPOIB_CM_RX_SG = ALIGN(IPOIB_CM_BUF_SIZE, PAGE_SIZE) / PAGE_SIZE,
+ /* +1 to accommodate residual data in the last SG element */
+ IPOIB_CM_RX_SG = ALIGN(IPOIB_CM_BUF_SIZE, PAGE_SIZE)/PAGE_SIZE + 1,
IPOIB_RX_RING_SIZE = 256,
IPOIB_TX_RING_SIZE = 128,
IPOIB_MAX_QUEUE_SIZE = 8192,
@@ -543,6 +548,8 @@ int ipoib_set_dev_features(struct ipoib_dev_priv *priv, struct ib_device *hca);
/* We don't support UC connections at the moment */
#define IPOIB_CM_SUPPORTED(ha) (ha[0] & (IPOIB_FLAGS_RC))
+extern int ipoib_cm_rx_sg;
+
#ifdef CONFIG_INFINIBAND_IPOIB_CM
extern int ipoib_max_conn_qp;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 933efce..0b5154f6 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -122,13 +122,13 @@ static int ipoib_cm_post_receive_nonsrq(struct net_device *dev,
wr->wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
- for (i = 0; i < IPOIB_CM_RX_SG; ++i)
+ for (i = 0; i < ipoib_cm_rx_sg; ++i)
sge[i].addr = rx->rx_ring[id].mapping[i];
ret = ib_post_recv(rx->qp, wr, &bad_wr);
if (unlikely(ret)) {
ipoib_warn(priv, "post recv failed for buf %d (%d)\n", id, ret);
- ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+ ipoib_cm_dma_unmap_rx(priv, ipoib_cm_rx_sg - 1,
rx->rx_ring[id].mapping);
dev_kfree_skb_any(rx->rx_ring[id].skb);
rx->rx_ring[id].skb = NULL;
@@ -199,7 +199,7 @@ static void ipoib_cm_free_rx_ring(struct net_device *dev,
for (i = 0; i < ipoib_recvq_size; ++i)
if (rx_ring[i].skb) {
- ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+ ipoib_cm_dma_unmap_rx(priv, ipoib_cm_rx_sg - 1,
rx_ring[i].mapping);
dev_kfree_skb_any(rx_ring[i].skb);
}
@@ -263,7 +263,7 @@ static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
if (!ipoib_cm_has_srq(dev)) {
attr.cap.max_recv_wr = ipoib_recvq_size;
- attr.cap.max_recv_sge = IPOIB_CM_RX_SG;
+ attr.cap.max_recv_sge = ipoib_cm_rx_sg;
}
return ib_create_qp(priv->pd, &attr);
@@ -382,7 +382,8 @@ static int ipoib_cm_nonsrq_init_rx(struct net_device *dev, struct ib_cm_id *cm_i
spin_unlock_irq(&priv->lock);
for (i = 0; i < ipoib_recvq_size; ++i) {
- if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i, IPOIB_CM_RX_SG - 1,
+ if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i,
+ ipoib_cm_rx_sg - 1,
rx->rx_ring[i].mapping,
GFP_KERNEL)) {
ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
@@ -1553,16 +1554,20 @@ int ipoib_cm_dev_init(struct net_device *dev)
ipoib_dbg(priv, "max_srq_sge=%d\n", attr.max_srq_sge);
- attr.max_srq_sge = min_t(int, IPOIB_CM_RX_SG, attr.max_srq_sge);
+ attr.max_srq_sge = min_t(int, ipoib_cm_rx_sg, attr.max_srq_sge);
ipoib_cm_create_srq(dev, attr.max_srq_sge);
if (ipoib_cm_has_srq(dev)) {
- priv->cm.max_cm_mtu = attr.max_srq_sge * PAGE_SIZE - 0x10;
+ int no_skb_frags = attr.max_srq_sge - 1;
+ u32 maxmtu;
+
+ maxmtu = no_skb_frags * PAGE_SIZE + IPOIB_CM_HEAD_SIZE - 0x10;
+ priv->cm.max_cm_mtu = min_t(int, maxmtu, IPOIB_CM_MTU);
priv->cm.num_frags = attr.max_srq_sge;
ipoib_dbg(priv, "max_cm_mtu = 0x%x, num_frags=%d\n",
priv->cm.max_cm_mtu, priv->cm.num_frags);
} else {
priv->cm.max_cm_mtu = IPOIB_CM_MTU;
- priv->cm.num_frags = IPOIB_CM_RX_SG;
+ priv->cm.num_frags = ipoib_cm_rx_sg;
}
ipoib_cm_init_rx_wr(dev, &priv->cm.rx_wr, priv->cm.rx_sge);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 1310acf..50fb941 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -73,6 +73,8 @@ module_param_named(debug_level, ipoib_debug_level, int, 0644);
MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0");
#endif
+int ipoib_cm_rx_sg;
+
struct ipoib_path_iter {
struct net_device *dev;
struct ipoib_path path;
@@ -1257,7 +1259,6 @@ static void ipoib_neigh_hash_uninit(struct net_device *dev)
wait_for_completion(&priv->ntbl.deleted);
}
-
int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
@@ -1719,6 +1720,10 @@ static void ipoib_remove_one(struct ib_device *device)
static int __init ipoib_init_module(void)
{
int ret;
+ int ipoib_cm_sg_len;
+
+ ipoib_cm_sg_len = IPOIB_CM_BUF_SIZE - IPOIB_CM_HEAD_SIZE;
+ ipoib_cm_rx_sg = ALIGN(ipoib_cm_sg_len, PAGE_SIZE)/PAGE_SIZE + 1;
ipoib_recvq_size = roundup_pow_of_two(ipoib_recvq_size);
ipoib_recvq_size = min(ipoib_recvq_size, IPOIB_MAX_QUEUE_SIZE);
--
1.8.2.1
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists