[Public] To simply code lines, I guess we can drop variable 'r'. And use 'return svm_ioctl(p, args->op.... ' directly.
Regards, Guchun -----Original Message----- From: amd-gfx <[email protected]> On Behalf Of Philip Yang Sent: Wednesday, January 26, 2022 2:04 AM To: [email protected] Cc: Yang, Philip <[email protected]>; Kuehling, Felix <[email protected]> Subject: [PATCH 1/1] drm/amdkfd: Don't take process mutex for svm ioctls SVM ioctls take proper svms->lock to handle race conditions, don't need take process mutex to serialize ioctls. This also fixes circular locking warning: WARNING: possible circular locking dependency detected Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&svms->deferred_list_work)); lock(&process->mutex); lock((work_completion)(&svms->deferred_list_work)); lock(&process->mutex); *** DEADLOCK *** Signed-off-by: Philip Yang <[email protected]> --- drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 337953af7c2f..70122978bdd0 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -1846,13 +1846,9 @@ static int kfd_ioctl_svm(struct file *filep, struct kfd_process *p, void *data) if (!args->start_addr || !args->size) return -EINVAL; - mutex_lock(&p->mutex); - r = svm_ioctl(p, args->op, args->start_addr, args->size, args->nattr, args->attrs); - mutex_unlock(&p->mutex); - return r; } #else -- 2.17.1
