* [PATCH] nvme: Remove double assignment of cq vector
@ 2019-09-05 14:50 Israel Rukshin
2019-09-05 14:59 ` Keith Busch
0 siblings, 1 reply; 5+ messages in thread
From: Israel Rukshin @ 2019-09-05 14:50 UTC (permalink / raw)
To: Linux-nvme; +Cc: Max Gurtovoy, Christoph Hellwig, Israel Rukshin, Sagi Grimberg
Poll queues don't use it, so the assignment should be only when
using IRQs.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
---
drivers/nvme/host/pci.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 10d3071d6098..492074c95b9b 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1560,7 +1560,6 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid, bool polled)
else if (result)
goto release_cq;
- nvmeq->cq_vector = vector;
nvme_init_queue(nvmeq, qid);
if (!polled) {
--
2.16.3
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] nvme: Remove double assignment of cq vector
2019-09-05 14:50 [PATCH] nvme: Remove double assignment of cq vector Israel Rukshin
@ 2019-09-05 14:59 ` Keith Busch
2019-09-05 15:10 ` Israel Rukshin
0 siblings, 1 reply; 5+ messages in thread
From: Keith Busch @ 2019-09-05 14:59 UTC (permalink / raw)
To: Israel Rukshin; +Cc: Max Gurtovoy, Christoph Hellwig, Linux-nvme, Sagi Grimberg
On Thu, Sep 05, 2019 at 02:50:48PM +0000, Israel Rukshin wrote:
> Poll queues don't use it, so the assignment should be only when
> using IRQs.
It's not really a double assignment. An interrupt driven queue may become
a polled queue after a reset, in which case this assignment serves to
clear it's previously assigned vector. It doesn't actually appear to
matter if we've cleared it or not when the NVMEQ_POLLED flag is set,
though.
> Signed-off-by: Israel Rukshin <israelr@mellanox.com>
> Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
> ---
> drivers/nvme/host/pci.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 10d3071d6098..492074c95b9b 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1560,7 +1560,6 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid, bool polled)
> else if (result)
> goto release_cq;
>
> - nvmeq->cq_vector = vector;
> nvme_init_queue(nvmeq, qid);
>
> if (!polled) {
> --
> 2.16.3
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nvme: Remove double assignment of cq vector
2019-09-05 14:59 ` Keith Busch
@ 2019-09-05 15:10 ` Israel Rukshin
2019-09-05 15:21 ` Keith Busch
2019-09-05 15:22 ` Max Gurtovoy
0 siblings, 2 replies; 5+ messages in thread
From: Israel Rukshin @ 2019-09-05 15:10 UTC (permalink / raw)
To: Keith Busch; +Cc: Max Gurtovoy, Christoph Hellwig, Linux-nvme, Sagi Grimberg
On 9/5/2019 5:59 PM, Keith Busch wrote:
> It's not really a double assignment. An interrupt driven queue may become
> a polled queue after a reset, in which case this assignment serves to
> clear it's previously assigned vector. It doesn't actually appear to
> matter if we've cleared it or not when the NVMEQ_POLLED flag is set,
> though.
So what about the second assignment when polled is false?
nvmeq->cq_vector = vector;
nvme_init_queue(nvmeq, qid);
if (!polled) {
nvmeq->cq_vector = vector; <<<<<
result = queue_request_irq(nvmeq);
Regards,
Israel
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nvme: Remove double assignment of cq vector
2019-09-05 15:10 ` Israel Rukshin
@ 2019-09-05 15:21 ` Keith Busch
2019-09-05 15:22 ` Max Gurtovoy
1 sibling, 0 replies; 5+ messages in thread
From: Keith Busch @ 2019-09-05 15:21 UTC (permalink / raw)
To: Israel Rukshin; +Cc: Max Gurtovoy, Christoph Hellwig, Linux-nvme, Sagi Grimberg
On Thu, Sep 05, 2019 at 03:10:35PM +0000, Israel Rukshin wrote:
> On 9/5/2019 5:59 PM, Keith Busch wrote:
> > It's not really a double assignment. An interrupt driven queue may become
> > a polled queue after a reset, in which case this assignment serves to
> > clear it's previously assigned vector. It doesn't actually appear to
> > matter if we've cleared it or not when the NVMEQ_POLLED flag is set,
> > though.
>
> So what about the second assignment when polled is false?
>
> nvmeq->cq_vector = vector;
> nvme_init_queue(nvmeq, qid);
>
> if (!polled) {
> nvmeq->cq_vector = vector; <<<<<
> result = queue_request_irq(nvmeq);
Oh sure, that one serves no purpose at all.
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] nvme: Remove double assignment of cq vector
2019-09-05 15:10 ` Israel Rukshin
2019-09-05 15:21 ` Keith Busch
@ 2019-09-05 15:22 ` Max Gurtovoy
1 sibling, 0 replies; 5+ messages in thread
From: Max Gurtovoy @ 2019-09-05 15:22 UTC (permalink / raw)
To: Israel Rukshin, Keith Busch; +Cc: Christoph Hellwig, Linux-nvme, Sagi Grimberg
On 9/5/2019 6:10 PM, Israel Rukshin wrote:
> On 9/5/2019 5:59 PM, Keith Busch wrote:
>> It's not really a double assignment. An interrupt driven queue may become
>> a polled queue after a reset, in which case this assignment serves to
>> clear it's previously assigned vector. It doesn't actually appear to
>> matter if we've cleared it or not when the NVMEQ_POLLED flag is set,
>> though.
> So what about the second assignment when polled is false?
>
> nvmeq->cq_vector = vector;
> nvme_init_queue(nvmeq, qid);
>
> if (!polled) {
> nvmeq->cq_vector = vector; <<<<<
let's remove the second assignment. The first one is good enough for
both IMO.
> result = queue_request_irq(nvmeq);
>
>
> Regards,
>
> Israel
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-09-05 15:22 UTC | newest]
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2019-09-05 14:50 [PATCH] nvme: Remove double assignment of cq vector Israel Rukshin
2019-09-05 14:59 ` Keith Busch
2019-09-05 15:10 ` Israel Rukshin
2019-09-05 15:21 ` Keith Busch
2019-09-05 15:22 ` Max Gurtovoy
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