Re: [MAINLINE 2/2] rds: ib: Add Dynamic Interrupt Moderation to CQs

Zhu Yanjun
2024-09-20T12:51:15Z

在 2024/9/20 17:42, Haakon Bugge 写道:
>
>
>> On 20 Sep 2024, at 09:47, Zhu Yanjun <yanjun.zhu@linux.dev> 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.

Which Oracle Linux distro includes this feature?
And what is the kernel version?

Zhu Yanjun

>
>
> 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@oracle.com>
>>> ---
>>> 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);
>>
>