diff options
author | Or Gerlitz | 2014-05-11 14:15:11 +0200 |
---|---|---|
committer | Roland Dreier | 2014-06-02 23:58:11 +0200 |
commit | 09b93088d75009807b72293f26e2634430ce5ba9 (patch) | |
tree | 78337f035d708879589063e779c5fa3a42183c2e /drivers/net/ethernet/mellanox/mlx4/en_rx.c | |
parent | IB: Return error for unsupported QP creation flags (diff) | |
download | kernel-qcow2-linux-09b93088d75009807b72293f26e2634430ce5ba9.tar.gz kernel-qcow2-linux-09b93088d75009807b72293f26e2634430ce5ba9.tar.xz kernel-qcow2-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 'drivers/net/ethernet/mellanox/mlx4/en_rx.c')
0 files changed, 0 insertions, 0 deletions