Re: [PATCH] drm/amdkfd: replace idr_init() by idr_init_base()

[Felix Kuehling]

On 2020-11-04 10:13 a.m., Deepak R Varma wrote:
idr_init() uses base 0 which is an invalid identifier. The new function
idr_init_base allows IDR to set the ID lookup from base 1. This avoids
all lookups that otherwise starts from 0 since 0 is always unused.

I disagree. We call idr_alloc with start=0 for both these IDRs. That 
means 0 seems to be a valid handle.

Regards,
  Felix



References: commit 6ce711f27500 ("idr: Make 1-based IDRs more efficient")

Signed-off-by: Deepak R Varma <mh12gx2...@gmail.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_events.c  | 2 +-
  drivers/gpu/drm/amd/amdkfd/kfd_process.c | 2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index ba2c2ce0c55a..b3339b53c8ad 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -230,7 +230,7 @@ static int create_other_event(struct kfd_process *p, struct 
kfd_event *ev)
  void kfd_event_init_process(struct kfd_process *p)
  {
        mutex_init(&p->event_mutex);
-       idr_init(&p->event_idr);
+       idr_init_base(&p->event_idr, 1);
        p->signal_page = NULL;
        p->signal_event_count = 0;
  }
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 65803e153a22..022e61babe30 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1289,7 +1289,7 @@ struct kfd_process_device 
*kfd_create_process_device_data(struct kfd_dev *dev,
        list_add(&pdd->per_device_list, &p->per_device_data);
  
  	/* Init idr used for memory handle translation */
-       idr_init(&pdd->alloc_idr);
+       idr_init_base(&pdd->alloc_idr, 1);
  
  	return pdd;