Re: [PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Sasha Levin]

Grabbed it for both 4.14 and 4.15, thanks Max!

On Mon, Apr 09, 2018 at 07:21:29PM +0300, Max Gurtovoy wrote:
>Hi Sasha,
>please consider taking a small fix for this one (also useful for 4.15):
>
>commit d3b9e8ad425cfd5b9116732e057f1b48e4d3bcb8
>Author: Max Gurtovoy 
>Date:   Mon Mar 5 20:09:48 2018 +0200
>
>RDMA/core: Reduce poll batch for direct cq polling
>
>Fix warning limit for kernel stack consumption:
>
>drivers/infiniband/core/cq.c: In function 'ib_process_cq_direct':
>drivers/infiniband/core/cq.c:78:1: error: the frame size of 1032 bytes
>is larger than 1024 bytes [-Werror=frame-larger-than=]
>
>Using smaller ib_wc array on the stack brings us comfortably below that
>limit again.
>
>Fixes: 246d8b184c10 ("IB/cq: Don't force IB_POLL_DIRECT poll 
>context for ib_process_cq_direct")
>Reported-by: Arnd Bergmann 
>Reviewed-by: Sergey Gorenko 
>Signed-off-by: Max Gurtovoy 
>Signed-off-by: Leon Romanovsky 
>Reviewed-by: Bart Van Assche 
>Acked-by: Arnd Bergmann 
>Signed-off-by: Jason Gunthorpe 
>
>
>-Max.
>
>
>On 4/9/2018 3:20 AM, Sasha Levin wrote:
>>From: Sagi Grimberg 
>>
>>[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]
>>
>>polling the completion queue directly does not interfere
>>with the existing polling logic, hence drop the requirement.
>>Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
>>CQ may trigger concurrent CQ processing.
>>
>>This can be used for polling mode ULPs.
>>
>>Cc: Bart Van Assche 
>>Reported-by: Steve Wise 
>>Signed-off-by: Sagi Grimberg 
>>[maxg: added wcs array argument to __ib_process_cq]
>>Signed-off-by: Max Gurtovoy 
>>Signed-off-by: Doug Ledford 
>>Signed-off-by: Sasha Levin 
>>---
>>  drivers/infiniband/core/cq.c | 23 +--
>>  1 file changed, 13 insertions(+), 10 deletions(-)
>>
>>diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
>>index f2ae75fa3128..c8c5a5a7f433 100644
>>--- a/drivers/infiniband/core/cq.c
>>+++ b/drivers/infiniband/core/cq.c
>>@@ -25,9 +25,10 @@
>>  #define IB_POLL_FLAGS \
>>  (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
>>-static int __ib_process_cq(struct ib_cq *cq, int budget)
>>+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc 
>>*poll_wc)
>>  {
>>  int i, n, completed = 0;
>>+ struct ib_wc *wcs = poll_wc ? : cq->wc;
>>  /*
>>   * budget might be (-1) if the caller does not
>>@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
>>   * minimum here.
>>   */
>>  while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
>>- budget - completed), cq->wc)) > 0) {
>>+ budget - completed), wcs)) > 0) {
>>  for (i = 0; i < n; i++) {
>>- struct ib_wc *wc = >wc[i];
>>+ struct ib_wc *wc = [i];
>>  if (wc->wr_cqe)
>>  wc->wr_cqe->done(cq, wc);
>>@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
>>   * @cq: CQ to process
>>   * @budget: number of CQEs to poll for
>>   *
>>- * This function is used to process all outstanding CQ entries on a
>>- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
>>- * context and does not ask for completion interrupts from the HCA.
>>+ * This function is used to process all outstanding CQ entries.
>>+ * It does not offload CQ processing to a different context and does
>>+ * not ask for completion interrupts from the HCA.
>>+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
>>+ * concurrent processing.
>>   *
>>   * Note: do not pass -1 as %budget unless it is guaranteed that the number
>>   * of completions that will be processed is small.
>>   */
>>  int ib_process_cq_direct(struct ib_cq *cq, int budget)
>>  {
>>- WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
>>+ struct ib_wc wcs[IB_POLL_BATCH];
>>- return __ib_process_cq(cq, budget);
>>+ return __ib_process_cq(cq, budget, wcs);
>>  }
>>  EXPORT_SYMBOL(ib_process_cq_direct);
>>@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)
>>  struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
>>  int completed;
>>- completed = __ib_process_cq(cq, budget);
>>+ completed = __ib_process_cq(cq, budget, NULL);
>>  if (completed < budget) {
>>  irq_poll_complete(>iop);
>>  if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
>>@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
>>  struct ib_cq *cq = container_of(work, struct ib_cq, work);
>>  int 

Re: [PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Sasha Levin]

Grabbed it for both 4.14 and 4.15, thanks Max!

On Mon, Apr 09, 2018 at 07:21:29PM +0300, Max Gurtovoy wrote:
>Hi Sasha,
>please consider taking a small fix for this one (also useful for 4.15):
>
>commit d3b9e8ad425cfd5b9116732e057f1b48e4d3bcb8
>Author: Max Gurtovoy 
>Date:   Mon Mar 5 20:09:48 2018 +0200
>
>RDMA/core: Reduce poll batch for direct cq polling
>
>Fix warning limit for kernel stack consumption:
>
>drivers/infiniband/core/cq.c: In function 'ib_process_cq_direct':
>drivers/infiniband/core/cq.c:78:1: error: the frame size of 1032 bytes
>is larger than 1024 bytes [-Werror=frame-larger-than=]
>
>Using smaller ib_wc array on the stack brings us comfortably below that
>limit again.
>
>Fixes: 246d8b184c10 ("IB/cq: Don't force IB_POLL_DIRECT poll 
>context for ib_process_cq_direct")
>Reported-by: Arnd Bergmann 
>Reviewed-by: Sergey Gorenko 
>Signed-off-by: Max Gurtovoy 
>Signed-off-by: Leon Romanovsky 
>Reviewed-by: Bart Van Assche 
>Acked-by: Arnd Bergmann 
>Signed-off-by: Jason Gunthorpe 
>
>
>-Max.
>
>
>On 4/9/2018 3:20 AM, Sasha Levin wrote:
>>From: Sagi Grimberg 
>>
>>[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]
>>
>>polling the completion queue directly does not interfere
>>with the existing polling logic, hence drop the requirement.
>>Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
>>CQ may trigger concurrent CQ processing.
>>
>>This can be used for polling mode ULPs.
>>
>>Cc: Bart Van Assche 
>>Reported-by: Steve Wise 
>>Signed-off-by: Sagi Grimberg 
>>[maxg: added wcs array argument to __ib_process_cq]
>>Signed-off-by: Max Gurtovoy 
>>Signed-off-by: Doug Ledford 
>>Signed-off-by: Sasha Levin 
>>---
>>  drivers/infiniband/core/cq.c | 23 +--
>>  1 file changed, 13 insertions(+), 10 deletions(-)
>>
>>diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
>>index f2ae75fa3128..c8c5a5a7f433 100644
>>--- a/drivers/infiniband/core/cq.c
>>+++ b/drivers/infiniband/core/cq.c
>>@@ -25,9 +25,10 @@
>>  #define IB_POLL_FLAGS \
>>  (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
>>-static int __ib_process_cq(struct ib_cq *cq, int budget)
>>+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc 
>>*poll_wc)
>>  {
>>  int i, n, completed = 0;
>>+ struct ib_wc *wcs = poll_wc ? : cq->wc;
>>  /*
>>   * budget might be (-1) if the caller does not
>>@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
>>   * minimum here.
>>   */
>>  while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
>>- budget - completed), cq->wc)) > 0) {
>>+ budget - completed), wcs)) > 0) {
>>  for (i = 0; i < n; i++) {
>>- struct ib_wc *wc = >wc[i];
>>+ struct ib_wc *wc = [i];
>>  if (wc->wr_cqe)
>>  wc->wr_cqe->done(cq, wc);
>>@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
>>   * @cq: CQ to process
>>   * @budget: number of CQEs to poll for
>>   *
>>- * This function is used to process all outstanding CQ entries on a
>>- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
>>- * context and does not ask for completion interrupts from the HCA.
>>+ * This function is used to process all outstanding CQ entries.
>>+ * It does not offload CQ processing to a different context and does
>>+ * not ask for completion interrupts from the HCA.
>>+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
>>+ * concurrent processing.
>>   *
>>   * Note: do not pass -1 as %budget unless it is guaranteed that the number
>>   * of completions that will be processed is small.
>>   */
>>  int ib_process_cq_direct(struct ib_cq *cq, int budget)
>>  {
>>- WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
>>+ struct ib_wc wcs[IB_POLL_BATCH];
>>- return __ib_process_cq(cq, budget);
>>+ return __ib_process_cq(cq, budget, wcs);
>>  }
>>  EXPORT_SYMBOL(ib_process_cq_direct);
>>@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)
>>  struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
>>  int completed;
>>- completed = __ib_process_cq(cq, budget);
>>+ completed = __ib_process_cq(cq, budget, NULL);
>>  if (completed < budget) {
>>  irq_poll_complete(>iop);
>>  if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
>>@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
>>  struct ib_cq *cq = container_of(work, struct ib_cq, work);
>>  int completed;
>>- completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
>>+ completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);
>>  if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
>>  ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
>>  queue_work(ib_comp_wq, >work);
>>

Re: [PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Max Gurtovoy]

Hi Sasha,
please consider taking a small fix for this one (also useful for 4.15):

commit d3b9e8ad425cfd5b9116732e057f1b48e4d3bcb8
Author: Max Gurtovoy 
Date:   Mon Mar 5 20:09:48 2018 +0200

RDMA/core: Reduce poll batch for direct cq polling

Fix warning limit for kernel stack consumption:

drivers/infiniband/core/cq.c: In function 'ib_process_cq_direct':
drivers/infiniband/core/cq.c:78:1: error: the frame size of 1032 bytes
is larger than 1024 bytes [-Werror=frame-larger-than=]

Using smaller ib_wc array on the stack brings us comfortably below that
limit again.

Fixes: 246d8b184c10 ("IB/cq: Don't force IB_POLL_DIRECT poll 
context for ib_process_cq_direct")

Reported-by: Arnd Bergmann 
Reviewed-by: Sergey Gorenko 
Signed-off-by: Max Gurtovoy 
Signed-off-by: Leon Romanovsky 
Reviewed-by: Bart Van Assche 
Acked-by: Arnd Bergmann 
Signed-off-by: Jason Gunthorpe 


-Max.


On 4/9/2018 3:20 AM, Sasha Levin wrote:

From: Sagi Grimberg 

[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]

polling the completion queue directly does not interfere
with the existing polling logic, hence drop the requirement.
Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
CQ may trigger concurrent CQ processing.

This can be used for polling mode ULPs.

Cc: Bart Van Assche 
Reported-by: Steve Wise 
Signed-off-by: Sagi Grimberg 
[maxg: added wcs array argument to __ib_process_cq]
Signed-off-by: Max Gurtovoy 
Signed-off-by: Doug Ledford 
Signed-off-by: Sasha Levin 
---
  drivers/infiniband/core/cq.c | 23 +--
  1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index f2ae75fa3128..c8c5a5a7f433 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -25,9 +25,10 @@
  #define IB_POLL_FLAGS \
(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
  
-static int __ib_process_cq(struct ib_cq *cq, int budget)

+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc)
  {
int i, n, completed = 0;
+   struct ib_wc *wcs = poll_wc ? : cq->wc;
  
  	/*

 * budget might be (-1) if the caller does not
@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
 * minimum here.
 */
while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
-   budget - completed), cq->wc)) > 0) {
+   budget - completed), wcs)) > 0) {
for (i = 0; i < n; i++) {
-   struct ib_wc *wc = >wc[i];
+   struct ib_wc *wc = [i];
  
  			if (wc->wr_cqe)

wc->wr_cqe->done(cq, wc);
@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
   * @cq:   CQ to process
   * @budget:   number of CQEs to poll for
   *
- * This function is used to process all outstanding CQ entries on a
- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
- * context and does not ask for completion interrupts from the HCA.
+ * This function is used to process all outstanding CQ entries.
+ * It does not offload CQ processing to a different context and does
+ * not ask for completion interrupts from the HCA.
+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
+ * concurrent processing.
   *
   * Note: do not pass -1 as %budget unless it is guaranteed that the number
   * of completions that will be processed is small.
   */
  int ib_process_cq_direct(struct ib_cq *cq, int budget)
  {
-   WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
+   struct ib_wc wcs[IB_POLL_BATCH];
  
-	return __ib_process_cq(cq, budget);

+   return __ib_process_cq(cq, budget, wcs);
  }
  EXPORT_SYMBOL(ib_process_cq_direct);
  
@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)

struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
int completed;
  
-	completed = __ib_process_cq(cq, budget);

+   completed = __ib_process_cq(cq, budget, NULL);
if (completed < budget) {
irq_poll_complete(>iop);
if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
struct ib_cq *cq = container_of(work, struct ib_cq, work);
int completed;
  
-	completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);

+   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);
if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
  

Re: [PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Max Gurtovoy]

Hi Sasha,
please consider taking a small fix for this one (also useful for 4.15):

commit d3b9e8ad425cfd5b9116732e057f1b48e4d3bcb8
Author: Max Gurtovoy 
Date:   Mon Mar 5 20:09:48 2018 +0200

RDMA/core: Reduce poll batch for direct cq polling

Fix warning limit for kernel stack consumption:

drivers/infiniband/core/cq.c: In function 'ib_process_cq_direct':
drivers/infiniband/core/cq.c:78:1: error: the frame size of 1032 bytes
is larger than 1024 bytes [-Werror=frame-larger-than=]

Using smaller ib_wc array on the stack brings us comfortably below that
limit again.

Fixes: 246d8b184c10 ("IB/cq: Don't force IB_POLL_DIRECT poll 
context for ib_process_cq_direct")

Reported-by: Arnd Bergmann 
Reviewed-by: Sergey Gorenko 
Signed-off-by: Max Gurtovoy 
Signed-off-by: Leon Romanovsky 
Reviewed-by: Bart Van Assche 
Acked-by: Arnd Bergmann 
Signed-off-by: Jason Gunthorpe 


-Max.


On 4/9/2018 3:20 AM, Sasha Levin wrote:

From: Sagi Grimberg 

[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]

polling the completion queue directly does not interfere
with the existing polling logic, hence drop the requirement.
Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
CQ may trigger concurrent CQ processing.

This can be used for polling mode ULPs.

Cc: Bart Van Assche 
Reported-by: Steve Wise 
Signed-off-by: Sagi Grimberg 
[maxg: added wcs array argument to __ib_process_cq]
Signed-off-by: Max Gurtovoy 
Signed-off-by: Doug Ledford 
Signed-off-by: Sasha Levin 
---
  drivers/infiniband/core/cq.c | 23 +--
  1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index f2ae75fa3128..c8c5a5a7f433 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -25,9 +25,10 @@
  #define IB_POLL_FLAGS \
(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
  
-static int __ib_process_cq(struct ib_cq *cq, int budget)

+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc)
  {
int i, n, completed = 0;
+   struct ib_wc *wcs = poll_wc ? : cq->wc;
  
  	/*

 * budget might be (-1) if the caller does not
@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
 * minimum here.
 */
while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
-   budget - completed), cq->wc)) > 0) {
+   budget - completed), wcs)) > 0) {
for (i = 0; i < n; i++) {
-   struct ib_wc *wc = >wc[i];
+   struct ib_wc *wc = [i];
  
  			if (wc->wr_cqe)

wc->wr_cqe->done(cq, wc);
@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
   * @cq:   CQ to process
   * @budget:   number of CQEs to poll for
   *
- * This function is used to process all outstanding CQ entries on a
- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
- * context and does not ask for completion interrupts from the HCA.
+ * This function is used to process all outstanding CQ entries.
+ * It does not offload CQ processing to a different context and does
+ * not ask for completion interrupts from the HCA.
+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
+ * concurrent processing.
   *
   * Note: do not pass -1 as %budget unless it is guaranteed that the number
   * of completions that will be processed is small.
   */
  int ib_process_cq_direct(struct ib_cq *cq, int budget)
  {
-   WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
+   struct ib_wc wcs[IB_POLL_BATCH];
  
-	return __ib_process_cq(cq, budget);

+   return __ib_process_cq(cq, budget, wcs);
  }
  EXPORT_SYMBOL(ib_process_cq_direct);
  
@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)

struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
int completed;
  
-	completed = __ib_process_cq(cq, budget);

+   completed = __ib_process_cq(cq, budget, NULL);
if (completed < budget) {
irq_poll_complete(>iop);
if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
struct ib_cq *cq = container_of(work, struct ib_cq, work);
int completed;
  
-	completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);

+   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);
if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
queue_work(ib_comp_wq, >work);

[PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Sasha Levin]

From: Sagi Grimberg 

[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]

polling the completion queue directly does not interfere
with the existing polling logic, hence drop the requirement.
Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
CQ may trigger concurrent CQ processing.

This can be used for polling mode ULPs.

Cc: Bart Van Assche 
Reported-by: Steve Wise 
Signed-off-by: Sagi Grimberg 
[maxg: added wcs array argument to __ib_process_cq]
Signed-off-by: Max Gurtovoy 
Signed-off-by: Doug Ledford 
Signed-off-by: Sasha Levin 
---
 drivers/infiniband/core/cq.c | 23 +--
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index f2ae75fa3128..c8c5a5a7f433 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -25,9 +25,10 @@
 #define IB_POLL_FLAGS \
(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
 
-static int __ib_process_cq(struct ib_cq *cq, int budget)
+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc)
 {
int i, n, completed = 0;
+   struct ib_wc *wcs = poll_wc ? : cq->wc;
 
/*
 * budget might be (-1) if the caller does not
@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
 * minimum here.
 */
while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
-   budget - completed), cq->wc)) > 0) {
+   budget - completed), wcs)) > 0) {
for (i = 0; i < n; i++) {
-   struct ib_wc *wc = >wc[i];
+   struct ib_wc *wc = [i];
 
if (wc->wr_cqe)
wc->wr_cqe->done(cq, wc);
@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
  * @cq:CQ to process
  * @budget:number of CQEs to poll for
  *
- * This function is used to process all outstanding CQ entries on a
- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
- * context and does not ask for completion interrupts from the HCA.
+ * This function is used to process all outstanding CQ entries.
+ * It does not offload CQ processing to a different context and does
+ * not ask for completion interrupts from the HCA.
+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
+ * concurrent processing.
  *
  * Note: do not pass -1 as %budget unless it is guaranteed that the number
  * of completions that will be processed is small.
  */
 int ib_process_cq_direct(struct ib_cq *cq, int budget)
 {
-   WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
+   struct ib_wc wcs[IB_POLL_BATCH];
 
-   return __ib_process_cq(cq, budget);
+   return __ib_process_cq(cq, budget, wcs);
 }
 EXPORT_SYMBOL(ib_process_cq_direct);
 
@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)
struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
int completed;
 
-   completed = __ib_process_cq(cq, budget);
+   completed = __ib_process_cq(cq, budget, NULL);
if (completed < budget) {
irq_poll_complete(>iop);
if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
struct ib_cq *cq = container_of(work, struct ib_cq, work);
int completed;
 
-   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
+   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);
if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
queue_work(ib_comp_wq, >work);
-- 
2.15.1

[PATCH AUTOSEL for 4.14 039/161] IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct

[Sasha Levin]

From: Sagi Grimberg 

[ Upstream commit 246d8b184c100e8eb6b4e8c88f232c2ed2a4e672 ]

polling the completion queue directly does not interfere
with the existing polling logic, hence drop the requirement.
Be aware that running ib_process_cq_direct with non IB_POLL_DIRECT
CQ may trigger concurrent CQ processing.

This can be used for polling mode ULPs.

Cc: Bart Van Assche 
Reported-by: Steve Wise 
Signed-off-by: Sagi Grimberg 
[maxg: added wcs array argument to __ib_process_cq]
Signed-off-by: Max Gurtovoy 
Signed-off-by: Doug Ledford 
Signed-off-by: Sasha Levin 
---
 drivers/infiniband/core/cq.c | 23 +--
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index f2ae75fa3128..c8c5a5a7f433 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -25,9 +25,10 @@
 #define IB_POLL_FLAGS \
(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
 
-static int __ib_process_cq(struct ib_cq *cq, int budget)
+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc)
 {
int i, n, completed = 0;
+   struct ib_wc *wcs = poll_wc ? : cq->wc;
 
/*
 * budget might be (-1) if the caller does not
@@ -35,9 +36,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
 * minimum here.
 */
while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
-   budget - completed), cq->wc)) > 0) {
+   budget - completed), wcs)) > 0) {
for (i = 0; i < n; i++) {
-   struct ib_wc *wc = >wc[i];
+   struct ib_wc *wc = [i];
 
if (wc->wr_cqe)
wc->wr_cqe->done(cq, wc);
@@ -60,18 +61,20 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
  * @cq:CQ to process
  * @budget:number of CQEs to poll for
  *
- * This function is used to process all outstanding CQ entries on a
- * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
- * context and does not ask for completion interrupts from the HCA.
+ * This function is used to process all outstanding CQ entries.
+ * It does not offload CQ processing to a different context and does
+ * not ask for completion interrupts from the HCA.
+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
+ * concurrent processing.
  *
  * Note: do not pass -1 as %budget unless it is guaranteed that the number
  * of completions that will be processed is small.
  */
 int ib_process_cq_direct(struct ib_cq *cq, int budget)
 {
-   WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
+   struct ib_wc wcs[IB_POLL_BATCH];
 
-   return __ib_process_cq(cq, budget);
+   return __ib_process_cq(cq, budget, wcs);
 }
 EXPORT_SYMBOL(ib_process_cq_direct);
 
@@ -85,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget)
struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
int completed;
 
-   completed = __ib_process_cq(cq, budget);
+   completed = __ib_process_cq(cq, budget, NULL);
if (completed < budget) {
irq_poll_complete(>iop);
if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
@@ -105,7 +108,7 @@ static void ib_cq_poll_work(struct work_struct *work)
struct ib_cq *cq = container_of(work, struct ib_cq, work);
int completed;
 
-   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
+   completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL);
if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
queue_work(ib_comp_wq, >work);
-- 
2.15.1