Re: [PATCH] hw/nvme: add trace events for ioeventfd

[Jinhao Fan]

at 3:10 PM, Klaus Jensen <its@irrelevant.dk> wrote:

> On Jul 20 10:47, Jinhao Fan wrote:
>> at 10:41 PM, Jinhao Fan <fanjinhao21s@ict.ac.cn> wrote:
>> 
>>> at 1:34 PM, Klaus Jensen <its@irrelevant.dk> wrote:
>>> 
>>>> From: Klaus Jensen <k.jensen@samsung.com>
>>>> 
>>>> While testing Jinhaos ioeventfd patch I found it useful with a couple of
>>>> additional trace events since we no longer see the mmio events.
>>>> 
>>>> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
>>>> ---
>>>> hw/nvme/ctrl.c       | 8 ++++++++
>>>> hw/nvme/trace-events | 4 ++++
>>>> 2 files changed, 12 insertions(+)
>>>> 
>>>> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
>>>> index 533ad14e7a61..09725ec49c5d 100644
>>>> --- a/hw/nvme/ctrl.c
>>>> +++ b/hw/nvme/ctrl.c
>>>> @@ -1346,6 +1346,8 @@ static void nvme_post_cqes(void *opaque)
>>>>   bool pending = cq->head != cq->tail;
>>>>   int ret;
>>>> 
>>>> +    trace_pci_nvme_post_cqes(cq->cqid);
>>>> +
>>>>   QTAILQ_FOREACH_SAFE(req, &cq->req_list, entry, next) {
>>>>       NvmeSQueue *sq;
>>>>       hwaddr addr;
>>>> @@ -4238,6 +4240,8 @@ static void nvme_cq_notifier(EventNotifier *e)
>>>>   NvmeCQueue *cq = container_of(e, NvmeCQueue, notifier);
>>>>   NvmeCtrl *n = cq->ctrl;
>>>> 
>>>> +    trace_pci_nvme_cq_notify(cq->cqid);
>>>> +
>>>>   event_notifier_test_and_clear(&cq->notifier);
>>>> 
>>>>   nvme_update_cq_head(cq);
>>>> @@ -4275,6 +4279,8 @@ static void nvme_sq_notifier(EventNotifier *e)
>>>> {
>>>>   NvmeSQueue *sq = container_of(e, NvmeSQueue, notifier);
>>>> 
>>>> +    trace_pci_nvme_sq_notify(sq->sqid);
>>>> +
>>>>   event_notifier_test_and_clear(&sq->notifier);
>>>> 
>>>>   nvme_process_sq(sq);
>>>> @@ -6240,6 +6246,8 @@ static void nvme_process_sq(void *opaque)
>>>>   NvmeCtrl *n = sq->ctrl;
>>>>   NvmeCQueue *cq = n->cq[sq->cqid];
>>>> 
>>>> +    trace_pci_nvme_process_sq(sq->sqid);
>>>> +
>>>>   uint16_t status;
>>>>   hwaddr addr;
>>>>   NvmeCmd cmd;
>>>> diff --git a/hw/nvme/trace-events b/hw/nvme/trace-events
>>>> index fccb79f48973..45dd708bd2fa 100644
>>>> --- a/hw/nvme/trace-events
>>>> +++ b/hw/nvme/trace-events
>>>> @@ -104,6 +104,10 @@ pci_nvme_mmio_shutdown_set(void) "shutdown bit set"
>>>> pci_nvme_mmio_shutdown_cleared(void) "shutdown bit cleared"
>>>> pci_nvme_shadow_doorbell_cq(uint16_t cqid, uint16_t new_shadow_doorbell) 
>>>> "cqid %"PRIu16" new_shadow_doorbell %"PRIu16""
>>>> pci_nvme_shadow_doorbell_sq(uint16_t sqid, uint16_t new_shadow_doorbell) 
>>>> "sqid %"PRIu16" new_shadow_doorbell %"PRIu16""
>>>> +pci_nvme_sq_notify(uint16_t sqid) "sqid %"PRIu16""
>>>> +pci_nvme_cq_notify(uint16_t cqid) "cqid %"PRIu16""
>>>> +pci_nvme_process_sq(uint16_t sqid) "sqid %"PRIu16""
>>>> +pci_nvme_post_cqes(uint16_t cqid) "cqid %"PRIu16""
>>>> pci_nvme_open_zone(uint64_t slba, uint32_t zone_idx, int all) "open zone, 
>>>> slba=%"PRIu64", idx=%"PRIu32", all=%"PRIi32""
>>>> pci_nvme_close_zone(uint64_t slba, uint32_t zone_idx, int all) "close 
>>>> zone, slba=%"PRIu64", idx=%"PRIu32", all=%"PRIi32""
>>>> pci_nvme_finish_zone(uint64_t slba, uint32_t zone_idx, int all) "finish 
>>>> zone, slba=%"PRIu64", idx=%"PRIu32", all=%"PRIi32""
>>>> -- 
>>>> 2.36.1
>>> 
>>> I agree on the addition of SQ and CQ notify trace events. But what is the
>>> purpose for adding tracepoints for nvme_process_sq and nvme_post_cqes?
>> 
>> I realized these two events are useful when debugging iothread support. We
>> are processing sqe and cqe’s in a batch in nvme_process_sq and
>> nvme_post_cqes. It is important to mark the beginning of the batch.
> 
> If you can add your Reviewed-by here, I can queue it up ;)

Of course :)

Reviewed-by: Jinhao Fan <fanjinhao21s@ict.ac.cn>