2021-11-21 17:41:38

by Christophe JAILLET

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Subject: [PATCH 1/2] drm/amdkfd: Use bitmap_zalloc() when applicable

'doorbell_bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
improve the semantic and avoid some open-coded arithmetic in allocator
arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.

Signed-off-by: Christophe JAILLET <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index f29b3932e3dc..172ee8763523 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1011,7 +1011,7 @@ static void kfd_process_destroy_pdds(struct kfd_process *p)
free_pages((unsigned long)pdd->qpd.cwsr_kaddr,
get_order(KFD_CWSR_TBA_TMA_SIZE));

- kfree(pdd->qpd.doorbell_bitmap);
+ bitmap_free(pdd->qpd.doorbell_bitmap);
idr_destroy(&pdd->alloc_idr);

kfd_free_process_doorbells(pdd->dev, pdd->doorbell_index);
@@ -1434,9 +1434,8 @@ static int init_doorbell_bitmap(struct qcm_process_device *qpd,
if (!KFD_IS_SOC15(dev->device_info->asic_family))
return 0;

- qpd->doorbell_bitmap =
- kzalloc(DIV_ROUND_UP(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
- BITS_PER_BYTE), GFP_KERNEL);
+ qpd->doorbell_bitmap = bitmap_zalloc(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS
+ GFP_KERNEL);
if (!qpd->doorbell_bitmap)
return -ENOMEM;

--
2.30.2



2021-11-21 17:41:47

by Christophe JAILLET

[permalink] [raw]
Subject: [PATCH 2/2] drm/amdkfd: Slighly optimize 'init_doorbell_bitmap()'

The 'doorbell_bitmap' bitmap has just been allocated. So we can use the
non-atomic '__set_bit()' function to save a few cycles as no concurrent
access can happen.

Signed-off-by: Christophe JAILLET <[email protected]>
---
bitmap_set() could certainly also be use, but range checking would be
tricky.
---
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 172ee8763523..2e9d341062c4 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1447,9 +1447,9 @@ static int init_doorbell_bitmap(struct qcm_process_device *qpd,

for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
if (i >= range_start && i <= range_end) {
- set_bit(i, qpd->doorbell_bitmap);
- set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
- qpd->doorbell_bitmap);
+ __set_bit(i, qpd->doorbell_bitmap);
+ __set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
+ qpd->doorbell_bitmap);
}
}

--
2.30.2


2021-11-22 21:44:30

by Felix Kuehling

[permalink] [raw]
Subject: Re: [PATCH 2/2] drm/amdkfd: Slighly optimize 'init_doorbell_bitmap()'

Am 2021-11-21 um 12:41 p.m. schrieb Christophe JAILLET:
> The 'doorbell_bitmap' bitmap has just been allocated. So we can use the
> non-atomic '__set_bit()' function to save a few cycles as no concurrent
> access can happen.
>
> Signed-off-by: Christophe JAILLET <[email protected]>

Thank you for the patches. I think the same sort of change (at least the
allocation/freeing part) could be applied to the queue_slot_bitmap in
kfd_process_queue_manager.c. Would you like to submit another revision
of this patch series that handles that as well?

Either way, this series is

Reviewed-by: Felix Kuehling <[email protected]>


> ---
> bitmap_set() could certainly also be use, but range checking would be
> tricky.
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index 172ee8763523..2e9d341062c4 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -1447,9 +1447,9 @@ static int init_doorbell_bitmap(struct qcm_process_device *qpd,
>
> for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
> if (i >= range_start && i <= range_end) {
> - set_bit(i, qpd->doorbell_bitmap);
> - set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
> - qpd->doorbell_bitmap);
> + __set_bit(i, qpd->doorbell_bitmap);
> + __set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
> + qpd->doorbell_bitmap);
> }
> }
>

2021-11-23 06:02:39

by Christophe JAILLET

[permalink] [raw]
Subject: Re: [PATCH 2/2] drm/amdkfd: Slighly optimize 'init_doorbell_bitmap()'

Le 22/11/2021 à 22:44, Felix Kuehling a écrit :
> Am 2021-11-21 um 12:41 p.m. schrieb Christophe JAILLET:
>> The 'doorbell_bitmap' bitmap has just been allocated. So we can use the
>> non-atomic '__set_bit()' function to save a few cycles as no concurrent
>> access can happen.
>>
>> Signed-off-by: Christophe JAILLET <[email protected]>
>
> Thank you for the patches. I think the same sort of change (at least the
> allocation/freeing part) could be applied to the queue_slot_bitmap in
> kfd_process_queue_manager.c. Would you like to submit another revision
> of this patch series that handles that as well?

I'll send a v2 which will fix the missing ',' spotted by the kernel test
robot and include kfd_process_queue_manager.c.

All my patches are compile tested (otherwise it is said bellow the ---).
Looks like I missed this one :(.

CJ

>
> Either way, this series is
>
> Reviewed-by: Felix Kuehling <[email protected]>
>
>
>> ---
>> bitmap_set() could certainly also be use, but range checking would be
>> tricky.
>> ---
>> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index 172ee8763523..2e9d341062c4 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -1447,9 +1447,9 @@ static int init_doorbell_bitmap(struct qcm_process_device *qpd,
>>
>> for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
>> if (i >= range_start && i <= range_end) {
>> - set_bit(i, qpd->doorbell_bitmap);
>> - set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
>> - qpd->doorbell_bitmap);
>> + __set_bit(i, qpd->doorbell_bitmap);
>> + __set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
>> + qpd->doorbell_bitmap);
>> }
>> }
>>
>