diff options
| author | Or Gerlitz <ogerlitz@mellanox.com> | 2014-05-11 12:15:11 (GMT) |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2014-06-02 21:58:11 (GMT) |
| commit | 09b93088d75009807b72293f26e2634430ce5ba9 (patch) | |
| tree | 78337f035d708879589063e779c5fa3a42183c2e | |
| parent | 60093dc0c8b6407bc7494cbcb3e84322cc6782c8 (diff) | |
| download | linux-09b93088d75009807b72293f26e2634430ce5ba9.tar.xz | |
IB: Add a QP creation flag to use GFP_NOIO allocations
This addresses a problem where NFS client writes over IPoIB connected
mode may deadlock on memory allocation/writeback.
The problem is not directly memory reclamation. There is an indirect
dependency between network filesystems writing back pages and
ipoib_cm_tx_init() due to how a kworker is used. Page reclaim cannot
make forward progress until ipoib_cm_tx_init() succeeds and it is
stuck in page reclaim itself waiting for network transmission.
Ordinarily this situation may be avoided by having the caller use
GFP_NOFS but ipoib_cm_tx_init() does not have that information.
To address this, take a general approach and add a new QP creation
flag that tells the low-level hardware driver to use GFP_NOIO for the
memory allocations related to the new QP.
Use the new flag in the ipoib connected mode path, and if the driver
doesn't support it, re-issue the QP creation without the flag.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_cm.c | 18 | ||||
| -rw-r--r-- | include/rdma/ib_verbs.h | 1 |
2 files changed, 16 insertions, 3 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index 1377f85..933efce 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -1030,10 +1030,20 @@ static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_ .cap.max_send_sge = 1, .sq_sig_type = IB_SIGNAL_ALL_WR, .qp_type = IB_QPT_RC, - .qp_context = tx + .qp_context = tx, + .create_flags = IB_QP_CREATE_USE_GFP_NOIO }; - return ib_create_qp(priv->pd, &attr); + struct ib_qp *tx_qp; + + tx_qp = ib_create_qp(priv->pd, &attr); + if (PTR_ERR(tx_qp) == -EINVAL) { + ipoib_warn(priv, "can't use GFP_NOIO for QPs on device %s, using GFP_KERNEL\n", + priv->ca->name); + attr.create_flags &= ~IB_QP_CREATE_USE_GFP_NOIO; + tx_qp = ib_create_qp(priv->pd, &attr); + } + return tx_qp; } static int ipoib_cm_send_req(struct net_device *dev, @@ -1104,12 +1114,14 @@ static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn, struct ipoib_dev_priv *priv = netdev_priv(p->dev); int ret; - p->tx_ring = vzalloc(ipoib_sendq_size * sizeof *p->tx_ring); + p->tx_ring = __vmalloc(ipoib_sendq_size * sizeof *p->tx_ring, + GFP_NOIO, PAGE_KERNEL); if (!p->tx_ring) { ipoib_warn(priv, "failed to allocate tx ring\n"); ret = -ENOMEM; goto err_tx; } + memset(p->tx_ring, 0, ipoib_sendq_size * sizeof *p->tx_ring); p->qp = ipoib_cm_create_tx_qp(p->dev, p); if (IS_ERR(p->qp)) { diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index acd8251..d75b02f 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -783,6 +783,7 @@ enum ib_qp_create_flags { IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK = 1 << 1, IB_QP_CREATE_NETIF_QP = 1 << 5, IB_QP_CREATE_SIGNATURE_EN = 1 << 6, + IB_QP_CREATE_USE_GFP_NOIO = 1 << 7, /* reserve bits 26-31 for low level drivers' internal use */ IB_QP_CREATE_RESERVED_START = 1 << 26, IB_QP_CREATE_RESERVED_END = 1 << 31, |