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| author | Sagi Grimberg | 2014-10-01 13:02:08 +0200 |
|---|---|---|
| committer | Roland Dreier | 2014-10-09 09:06:06 +0200 |
| commit | 183cfa434ec90897b1423ce4f916e8a237139133 (patch) | |
| tree | 9987bfe5479c8f6792adafbc0221e704dc657613 /drivers/infiniband | |
| parent | IB/iser: Centralize iser completion contexts (diff) | |
| download | kernel-qcow2-linux-183cfa434ec90897b1423ce4f916e8a237139133.tar.gz kernel-qcow2-linux-183cfa434ec90897b1423ce4f916e8a237139133.tar.xz kernel-qcow2-linux-183cfa434ec90897b1423ce4f916e8a237139133.zip | |
IB/iser: Use internal polling budget to avoid possible live-lock
We need a way to guarentee that we don't stay in soft-IRQ context for
too long. We might starve other pending CQ tasklets or worse lock
against application trying to issue IO on the running CPU.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/ulp/iser/iser_verbs.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c index 94d1b46b467a..e31ac57accc9 100644 --- a/drivers/infiniband/ulp/iser/iser_verbs.c +++ b/drivers/infiniband/ulp/iser/iser_verbs.c @@ -42,6 +42,8 @@ #define ISER_MAX_RX_CQ_LEN (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN) #define ISER_MAX_TX_CQ_LEN (ISER_QP_MAX_REQ_DTOS * ISCSI_ISER_MAX_CONN) +static int iser_cq_poll_limit = 512; + static void iser_cq_tasklet_fn(unsigned long data); static void iser_cq_callback(struct ib_cq *cq, void *cq_context); static int iser_drain_tx_cq(struct iser_comp *comp); @@ -1248,6 +1250,8 @@ static void iser_cq_tasklet_fn(unsigned long data) completed_rx++; if (!(completed_rx & 63)) completed_tx += iser_drain_tx_cq(comp); + if (completed_rx >= iser_cq_poll_limit) + break; } /* #warning "it is assumed here that arming CQ only once its empty" * * " would not cause interrupts to be missed" */ |