> On 20 Sep 2024, at 09:47, Zhu Yanjun <yanjun.zhu@xxxxxxxxx> wrote:
>
> 在 2024/9/18 16:35, Håkon Bugge 写道:
>> With the support from ib_core to use Dynamic Interrupt Moderation
>> (DIM) from legacy ULPs, which uses ib_create_cq(), we enable that
>> feature for the receive and send CQs in RDS.
>
> Hi, Haakon
>
> I am interested in this patch series. I just wonder if the performance of rds is increased after DIM is used in legacy ULPs?
> That is, is there any benefit to legacy ULPs after DIM is used?
>
> Do you have any test results about this DIM?
Yes, please see the cover letter of this commit.
Thxs, Håkon
>
> Thanks,
> Zhu Yanjun
>
>> A set of rds-stress runs have been done. bcopy read + write for
>> payload 8448 and 16640 bytes and ack/req of 256 bytes. Number of QPs
>> varies from 8 to 128, number of threads (i.e. rds-stress processes)
>> from one to 16 and a depth of four. A limit has been applied such that
>> the number of processes times the number of QPs never exceeds 128. All
>> in all, 61 rds-stress runs.
>> For brevity, only the rows showing a +/- 3% deviation or larger from
>> base is listed. The geometric mean of the ratios (IOPS_test /
>> IOPS_base) is calculated for all 61 runs, and that gives the best
>> possible "average" impact of the commits.
>> In the following, "base" is v6.11-rc7. "test" is the same
>> kernel with the following two commits:
>> * rds: ib: Add Dynamic Interrupt Moderation to CQs (this commit)
>> * RDMA/core: Enable legacy ULPs to use RDMA DIM
>> This is executed between two X8-2 with CX-5 using fw 16.35.3502. These
>> BM systems were instantiated with one VF, which were used for the
>> test:
>> base test
>> ACK REQ QPS THR DEP IOPS IOPS Percent
>> 256 8448 8 1 4 634463 658162 3.7
>> 256 8448 8 2 4 862648 997358 15.6
>> 256 8448 8 4 4 950458 1113991 17.2
>> 256 8448 8 8 4 932120 1127024 20.9
>> 256 8448 8 16 4 944977 1133885 20.0
>> 8448 256 8 2 4 858663 975563 13.6
>> 8448 256 8 4 4 934884 1098854 17.5
>> 8448 256 8 8 4 928247 1116015 20.2
>> 8448 256 8 16 4 938864 1123455 19.7
>> 256 8448 64 1 4 965985 918445 -4.9
>> 8448 256 64 1 4 963280 918239 -4.7
>> 256 16640 8 2 4 544670 582330 6.9
>> 256 16640 8 4 4 554873 597553 7.7
>> 256 16640 8 8 4 551799 597479 8.3
>> 256 16640 8 16 4 553041 597898 8.1
>> 16640 256 8 2 4 544644 578331 6.2
>> 16640 256 8 4 4 553944 594627 7.3
>> 16640 256 8 8 4 551388 594737 7.9
>> 16640 256 8 16 4 552986 596581 7.9
>> Geometric mean of ratios: 1.03
>> Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
>> ---
>> net/rds/ib_cm.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>> diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
>> index 26b069e1999df..79603d86b6c02 100644
>> --- a/net/rds/ib_cm.c
>> +++ b/net/rds/ib_cm.c
>> @@ -259,6 +259,7 @@ static void rds_ib_cq_comp_handler_recv(struct ib_cq *cq, void *context)
>> static void poll_scq(struct rds_ib_connection *ic, struct ib_cq *cq,
>> struct ib_wc *wcs)
>> {
>> + int ncompleted = 0;
>> int nr, i;
>> struct ib_wc *wc;
>> @@ -276,7 +277,10 @@ static void poll_scq(struct rds_ib_connection *ic, struct ib_cq *cq,
>> rds_ib_mr_cqe_handler(ic, wc);
>> }
>> + ncompleted += nr;
>> }
>> + if (cq->dim)
>> + rdma_dim(cq->dim, ncompleted);
>> }
>> static void rds_ib_tasklet_fn_send(unsigned long data)
>> @@ -304,6 +308,7 @@ static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,
>> struct ib_wc *wcs,
>> struct rds_ib_ack_state *ack_state)
>> {
>> + int ncompleted = 0;
>> int nr, i;
>> struct ib_wc *wc;
>> @@ -316,7 +321,10 @@ static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,
>> rds_ib_recv_cqe_handler(ic, wc, ack_state);
>> }
>> + ncompleted += nr;
>> }
>> + if (cq->dim)
>> + rdma_dim(cq->dim, ncompleted);
>> }
>> static void rds_ib_tasklet_fn_recv(unsigned long data)
>> @@ -542,6 +550,7 @@ static int rds_ib_setup_qp(struct rds_connection *conn)
>> ic->i_scq_vector = ibdev_get_unused_vector(rds_ibdev);
>> cq_attr.cqe = ic->i_send_ring.w_nr + fr_queue_space + 1;
>> cq_attr.comp_vector = ic->i_scq_vector;
>> + cq_attr.flags |= IB_CQ_MODERATE;
>> ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
>> rds_ib_cq_event_handler, conn,
>> &cq_attr);
>> @@ -556,6 +565,7 @@ static int rds_ib_setup_qp(struct rds_connection *conn)
>> ic->i_rcq_vector = ibdev_get_unused_vector(rds_ibdev);
>> cq_attr.cqe = ic->i_recv_ring.w_nr;
>> cq_attr.comp_vector = ic->i_rcq_vector;
>> + cq_attr.flags |= IB_CQ_MODERATE;
>> ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
>> rds_ib_cq_event_handler, conn,
>> &cq_attr);
>
