On Wed, Jul 18, 2018 at 01:51:20AM -0700, Vijay Immanuel wrote:
> On Tue, Jul 17, 2018 at 12:04:47AM +0300, Yuval Shaia wrote:
> > On Mon, Jul 09, 2018 at 07:38:53PM -0700, Vijay Immanuel wrote:
> > > A QP must use the same NIC TX queue to maintain packet order. The TX
> > > queue is usually selected based on the core from which the transmit
> > > was originated.
> > > Assign QPs to cores to better spread traffic across TX queues. This
> > > requires scheduling the tasklets in the cpu assigned to the QP. The
> > > transmit cpu is selected based on the source QPN.
> >
> > Can you share test results?
Hi Vijay,
>
> I'm running NVMeoF host and target over RXE, single SSD, 40Gbps network, one switch.
> IOPs (FIO 4K random reads, qd 64, jobs 4) - 80,000 (w/o patch), 141,000 (w/ patch).
> Latency (FIO 4K random reads, qd 1, jobs 1) - 173 us (w/o patch), 180 us (w/ patch).
> BW Sequential read and write were similar in either case, about 1,100 MB/s.
I tried this patch with much more simpler setup - a QEMU VM with 4 CPUs and
4G RAM.
Unfortunately i was not happy with the results, maybe i'm using the wrong
tools for performance measurements but what i saw is the opposite, with
this patch numbers was worse than without.
I ran ibv_rc_pingpong where server and clients resides on the same VM with
4k and 1m message sizes and got this:
w/o w/
---------------------
4k: ~19 ~31
1m: ~3847 ~5647
Result is usec/iter.
Regardless of this, i briefly reviewed the patch and found no logical
mistakes in it but still wanted to put the things on the table.
Yuval
>
> >
> > >
> > > Signed-off-by: Vijay Immanuel <vijayi@xxxxxxxxxxxxxxxxx>
> > > ---
> > > Changes in v2:
> > > - Removed use of comp_vector for selecing the core.
> > > - Removed scheduling the req task for user QPs.
> > >
> > > drivers/infiniband/sw/rxe/rxe_comp.c | 8 +------
> > > drivers/infiniband/sw/rxe/rxe_qp.c | 10 +++++---
> > > drivers/infiniband/sw/rxe/rxe_resp.c | 8 +------
> > > drivers/infiniband/sw/rxe/rxe_task.c | 45 +++++++++++++++++++++++++++++++++---
> > > drivers/infiniband/sw/rxe/rxe_task.h | 7 +++++-
> > > 5 files changed, 57 insertions(+), 21 deletions(-)
> > >
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c
> > > index 6cdc40e..189f80e 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_comp.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_comp.c
> > > @@ -149,14 +149,8 @@ void retransmit_timer(struct timer_list *t)
> > > void rxe_comp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp,
> > > struct sk_buff *skb)
> > > {
> > > - int must_sched;
> > > -
> > > skb_queue_tail(&qp->resp_pkts, skb);
> > > -
> > > - must_sched = skb_queue_len(&qp->resp_pkts) > 1;
> > > - if (must_sched != 0)
> > > - rxe_counter_inc(rxe, RXE_CNT_COMPLETER_SCHED);
> > > - rxe_run_task(&qp->comp.task, must_sched);
> > > + rxe_run_task(&qp->comp.task, 1);
> > > }
> > >
> > > static inline enum comp_state get_wqe(struct rxe_qp *qp,
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
> > > index b9f7aa1..dc11227 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_qp.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_qp.c
> > > @@ -221,6 +221,7 @@ static int rxe_qp_init_req(struct rxe_dev *rxe, struct rxe_qp *qp,
> > > {
> > > int err;
> > > int wqe_size;
> > > + int qp_cpu;
> > >
> > > err = sock_create_kern(&init_net, AF_INET, SOCK_DGRAM, 0, &qp->sk);
> > > if (err < 0)
> > > @@ -260,9 +261,10 @@ static int rxe_qp_init_req(struct rxe_dev *rxe, struct rxe_qp *qp,
> > > spin_lock_init(&qp->sq.sq_lock);
> > > skb_queue_head_init(&qp->req_pkts);
> > >
> > > - rxe_init_task(rxe, &qp->req.task, qp,
> > > + qp_cpu = qp_num(qp) % num_online_cpus();
> > > + rxe_init_task(rxe, &qp->req.task, qp_cpu, qp,
> > > rxe_requester, "req");
> > > - rxe_init_task(rxe, &qp->comp.task, qp,
> > > + rxe_init_task(rxe, &qp->comp.task, qp_cpu, qp,
> > > rxe_completer, "comp");
> > >
> > > qp->qp_timeout_jiffies = 0; /* Can't be set for UD/UC in modify_qp */
> > > @@ -280,6 +282,7 @@ static int rxe_qp_init_resp(struct rxe_dev *rxe, struct rxe_qp *qp,
> > > {
> > > int err;
> > > int wqe_size;
> > > + int qp_cpu;
> > >
> > > if (!qp->srq) {
> > > qp->rq.max_wr = init->cap.max_recv_wr;
> > > @@ -311,7 +314,8 @@ static int rxe_qp_init_resp(struct rxe_dev *rxe, struct rxe_qp *qp,
> > >
> > > skb_queue_head_init(&qp->resp_pkts);
> > >
> > > - rxe_init_task(rxe, &qp->resp.task, qp,
> > > + qp_cpu = qp_num(qp) % num_online_cpus();
> > > + rxe_init_task(rxe, &qp->resp.task, qp_cpu, qp,
> > > rxe_responder, "resp");
> > >
> > > qp->resp.opcode = OPCODE_NONE;
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> > > index 955ff3b..853ab49 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> > > @@ -107,15 +107,9 @@ static char *resp_state_name[] = {
> > > void rxe_resp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp,
> > > struct sk_buff *skb)
> > > {
> > > - int must_sched;
> > > - struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
> > > -
> > > skb_queue_tail(&qp->req_pkts, skb);
> > >
> > > - must_sched = (pkt->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST) ||
> > > - (skb_queue_len(&qp->req_pkts) > 1);
> > > -
> > > - rxe_run_task(&qp->resp.task, must_sched);
> > > + rxe_run_task(&qp->resp.task, 1);
> > > }
> > >
> > > static inline enum resp_states get_req(struct rxe_qp *qp,
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c
> > > index 08f05ac..8b7cb97 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_task.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_task.c
> > > @@ -37,6 +37,8 @@
> > >
> > > #include "rxe_task.h"
> > >
> > > +static void rxe_run_task_local(void *data);
> > > +
> > > int __rxe_do_task(struct rxe_task *task)
> > >
> > > {
> > > @@ -63,6 +65,7 @@ void rxe_do_task(unsigned long data)
> > > struct rxe_task *task = (struct rxe_task *)data;
> > >
> > > spin_lock_irqsave(&task->state_lock, flags);
> > > + task->scheduled = false;
> > > switch (task->state) {
> > > case TASK_STATE_START:
> > > task->state = TASK_STATE_BUSY;
> > > @@ -108,20 +111,27 @@ void rxe_do_task(unsigned long data)
> > > pr_warn("%s failed with bad state %d\n", __func__,
> > > task->state);
> > > }
> > > +
> > > + if (!cont && task->scheduled)
> > > + tasklet_schedule(&task->tasklet);
> > > spin_unlock_irqrestore(&task->state_lock, flags);
> > > } while (cont);
> > >
> > > task->ret = ret;
> > > }
> > >
> > > -int rxe_init_task(void *obj, struct rxe_task *task,
> > > +int rxe_init_task(void *obj, struct rxe_task *task, int cpu,
> > > void *arg, int (*func)(void *), char *name)
> > > {
> > > + task->cpu = cpu;
> > > task->obj = obj;
> > > task->arg = arg;
> > > task->func = func;
> > > + task->csd.func = rxe_run_task_local;
> > > + task->csd.info = task;
> > > snprintf(task->name, sizeof(task->name), "%s", name);
> > > task->destroyed = false;
> > > + task->scheduled = false;
> > >
> > > tasklet_init(&task->tasklet, rxe_do_task, (unsigned long)task);
> > >
> > > @@ -151,15 +161,44 @@ void rxe_cleanup_task(struct rxe_task *task)
> > > tasklet_kill(&task->tasklet);
> > > }
> > >
> > > +static void rxe_run_task_local(void *data)
> > > +{
> > > + struct rxe_task *task = (struct rxe_task *)data;
> > > +
> > > + if (task->destroyed)
> > > + return;
> > > +
> > > + tasklet_schedule(&task->tasklet);
> > > +}
> > > +
> > > void rxe_run_task(struct rxe_task *task, int sched)
> > > {
> > > + int cpu;
> > > + unsigned long flags;
> > > +
> > > if (task->destroyed)
> > > return;
> > >
> > > - if (sched)
> > > + if (!sched) {
> > > + rxe_do_task((unsigned long)task);
> > > + return;
> > > + }
> > > +
> > > + spin_lock_irqsave(&task->state_lock, flags);
> > > + if (task->scheduled || task->state != TASK_STATE_START) {
> > > + task->scheduled = true;
> > > + spin_unlock_irqrestore(&task->state_lock, flags);
> > > + return;
> > > + }
> > > + task->scheduled = true;
> > > + spin_unlock_irqrestore(&task->state_lock, flags);
> > > +
> > > + cpu = get_cpu();
> > > + if (task->cpu == cpu || !cpu_online(task->cpu))
> > > tasklet_schedule(&task->tasklet);
> > > else
> > > - rxe_do_task((unsigned long)task);
> > > + smp_call_function_single_async(task->cpu, &task->csd);
> > > + put_cpu();
> > > }
> > >
> > > void rxe_disable_task(struct rxe_task *task)
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_task.h b/drivers/infiniband/sw/rxe/rxe_task.h
> > > index 08ff42d..1470dee 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_task.h
> > > +++ b/drivers/infiniband/sw/rxe/rxe_task.h
> > > @@ -34,6 +34,8 @@
> > > #ifndef RXE_TASK_H
> > > #define RXE_TASK_H
> > >
> > > +#include <linux/smp.h>
> > > +
> > > enum {
> > > TASK_STATE_START = 0,
> > > TASK_STATE_BUSY = 1,
> > > @@ -48,13 +50,16 @@ enum {
> > > struct rxe_task {
> > > void *obj;
> > > struct tasklet_struct tasklet;
> > > + int cpu;
> > > int state;
> > > spinlock_t state_lock; /* spinlock for task state */
> > > void *arg;
> > > int (*func)(void *arg);
> > > + call_single_data_t csd;
> > > int ret;
> > > char name[16];
> > > bool destroyed;
> > > + bool scheduled;
> > > };
> > >
> > > /*
> > > @@ -62,7 +67,7 @@ struct rxe_task {
> > > * arg => parameter to pass to fcn
> > > * fcn => function to call until it returns != 0
> > > */
> > > -int rxe_init_task(void *obj, struct rxe_task *task,
> > > +int rxe_init_task(void *obj, struct rxe_task *task, int cpu,
> > > void *arg, int (*func)(void *), char *name);
> > >
> > > /* cleanup task */
> > > --
> > > 2.7.4
> > >
> > > --
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