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| author | Steve Wise <swise@opengridcomputing.com> | 2010-05-20 16:57:43 -0500 |
|---|---|---|
| committer | Roland Dreier <rolandd@cisco.com> | 2010-05-24 21:08:01 -0700 |
| commit | 84172dee05cbce6ae791eac481ef4d8590cda791 (patch) | |
| tree | d631f0991e8be72d1d4d1cd2e1ce8d32eb5116e5 /drivers/infiniband | |
| parent | 895cf5f3d6cb72825919a39ae48a41476a821e65 (diff) | |
| download | linux-3.10-84172dee05cbce6ae791eac481ef4d8590cda791.tar.gz linux-3.10-84172dee05cbce6ae791eac481ef4d8590cda791.tar.bz2 linux-3.10-84172dee05cbce6ae791eac481ef4d8590cda791.zip | |
RDMA/cxgb4: Optimize CQ overflow detection
1) save the timestamp flit in the cq when we consume a CQE.
2) always compare the saved flit with the previous entry flit when
reading the next CQE entry. If the flits don't compare, then we
have overflowed.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/cxgb4/cq.c | 1 | ||||
| -rw-r--r-- | drivers/infiniband/hw/cxgb4/t4.h | 28 |
2 files changed, 17 insertions, 12 deletions
diff --git a/drivers/infiniband/hw/cxgb4/cq.c b/drivers/infiniband/hw/cxgb4/cq.c index 46ac00f728f..2447f529548 100644 --- a/drivers/infiniband/hw/cxgb4/cq.c +++ b/drivers/infiniband/hw/cxgb4/cq.c @@ -373,6 +373,7 @@ static void create_read_req_cqe(struct t4_wq *wq, struct t4_cqe *hw_cqe, V_CQE_SWCQE(SW_CQE(hw_cqe)) | V_CQE_OPCODE(FW_RI_READ_REQ) | V_CQE_TYPE(1)); + read_cqe->bits_type_ts = hw_cqe->bits_type_ts; } /* diff --git a/drivers/infiniband/hw/cxgb4/t4.h b/drivers/infiniband/hw/cxgb4/t4.h index d0e8af35240..712bc5620d3 100644 --- a/drivers/infiniband/hw/cxgb4/t4.h +++ b/drivers/infiniband/hw/cxgb4/t4.h @@ -434,7 +434,7 @@ struct t4_cq { struct c4iw_rdev *rdev; u64 ugts; size_t memsize; - u64 timestamp; + __be64 bits_type_ts; u32 cqid; u16 size; /* including status page */ u16 cidx; @@ -487,6 +487,7 @@ static inline void t4_swcq_consume(struct t4_cq *cq) static inline void t4_hwcq_consume(struct t4_cq *cq) { + cq->bits_type_ts = cq->queue[cq->cidx].bits_type_ts; cq->cidx_inc++; if (++cq->cidx == cq->size) { cq->cidx = 0; @@ -501,20 +502,23 @@ static inline int t4_valid_cqe(struct t4_cq *cq, struct t4_cqe *cqe) static inline int t4_next_hw_cqe(struct t4_cq *cq, struct t4_cqe **cqe) { - int ret = 0; - u64 bits_type_ts = be64_to_cpu(cq->queue[cq->cidx].bits_type_ts); + int ret; + u16 prev_cidx; - if (G_CQE_GENBIT(bits_type_ts) == cq->gen) { - *cqe = &cq->queue[cq->cidx]; - cq->timestamp = G_CQE_TS(bits_type_ts); - } else if (G_CQE_TS(bits_type_ts) > cq->timestamp) - ret = -EOVERFLOW; + if (cq->cidx == 0) + prev_cidx = cq->size - 1; else - ret = -ENODATA; - if (ret == -EOVERFLOW) { - printk(KERN_ERR MOD "cq overflow cqid %u\n", cq->cqid); + prev_cidx = cq->cidx - 1; + + if (cq->queue[prev_cidx].bits_type_ts != cq->bits_type_ts) { + ret = -EOVERFLOW; cq->error = 1; - } + printk(KERN_ERR MOD "cq overflow cqid %u\n", cq->cqid); + } else if (t4_valid_cqe(cq, &cq->queue[cq->cidx])) { + *cqe = &cq->queue[cq->cidx]; + ret = 0; + } else + ret = -ENODATA; return ret; } |