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| author | Or Gerlitz <ogerlitz@mellanox.com> | 2014-05-11 15:15:11 +0300 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2014-06-02 14:58:11 -0700 |
| commit | 09b93088d75009807b72293f26e2634430ce5ba9 (patch) | |
| tree | 78337f035d708879589063e779c5fa3a42183c2e /include/rdma | |
| parent | 60093dc0c8b6407bc7494cbcb3e84322cc6782c8 (diff) | |
| download | linux-09b93088d75009807b72293f26e2634430ce5ba9.tar.gz linux-09b93088d75009807b72293f26e2634430ce5ba9.tar.bz2 linux-09b93088d75009807b72293f26e2634430ce5ba9.zip | |
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>
Diffstat (limited to 'include/rdma')
| -rw-r--r-- | include/rdma/ib_verbs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index acd825182977..d75b02f9c80d 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, |