Hi Inki, On 08/17/2015 06:03 PM, Inki Dae wrote: > On 2015년 08월 17일 17:17, Joonyoung Shim wrote: >> On 08/17/2015 04:52 PM, Inki Dae wrote: >>> On 2015년 08월 17일 14:29, Joonyoung Shim wrote: >>>> On 08/16/2015 02:07 PM, Inki Dae wrote: >>>>> On 2015년 07월 28일 17:53, Joonyoung Shim wrote: >>>>>> The drm_gem_object_release() function already performs this cleanup, >>>>>> so there is no reason to do it explicitly. >>>>>> >>>>>> Signed-off-by: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx> >>>>>> --- >>>>>> drivers/gpu/drm/exynos/exynos_drm_gem.c | 3 --- >>>>>> 1 file changed, 3 deletions(-) >>>>>> >>>>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c >>>>>> index c76aa8a..ab7d029 100644 >>>>>> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c >>>>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c >>>>>> @@ -100,8 +100,6 @@ out: >>>>>> exynos_drm_fini_buf(obj->dev, buf); >>>>>> exynos_gem_obj->buffer = NULL; >>>>>> >>>>>> - drm_gem_free_mmap_offset(obj); >>>>>> - >>>>>> /* release file pointer to gem object. */ >>>>>> drm_gem_object_release(obj); >>>>>> >>>>>> @@ -600,7 +598,6 @@ int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) >>>>>> >>>>>> err_close_vm: >>>>>> drm_gem_vm_close(vma); >>>>>> - drm_gem_free_mmap_offset(obj); >>>>> >>>>> Without previous patch, drm_gem_free_mmap_offset is required. I guess >>>>> the reason you removed above line is that you thought >>>>> drm_gem_object_release function would be called by drm_gem_vm_close >>>>> function which drops a reference of the gem object. >>>>> >>>>> However, drm_gem_vm_close should be a pair with drm_gem_vm_open >>>>> function. These will be called whenever a process opens or closes the >>>>> VMA. So the reference count of the gem object had already been taken by >>>>> open operation when a new reference to the VMA had been created. >>>>> >>>> >>>> This changes is not related with drm_gem_vm_close and prior patch. Why >>>> should free mmap offset when mmap operation is failed? The mmap offset >>>> can be used repeatedly. >>> >>> Isn't vm space of vm manager still used even if any user-space process >>> doesn't use the region? And if mmap is failed, then the user-space >>> process will be terminated. Do you think it can be re-tried? However, >>> mmap system call never return -EAGAIN. Is it reasonable to you? I cannot >>> understand how the mmap offset can be re-used. So can you show me some >>> example? >>> >> >> Currently, mmap offset of exynos-drm gem is made by >> DRM_IOCTL_MODE_MAP_DUMB ioctl and mmap() ioctl just uses the mmap >> offset. User will use same mmap offset about same gem. It's why mmap >> offset made by DRM_IOCTL_MODE_MAP_DUMB ioctl is unnecessary, it's just >> enough to make mmap offset from when gem is create. You can get a >> reference from drm_gem_cma_helper.c file. > > Hmm... It's not that the mmap offset can be re-used or not. It's that > the mmap offset should be released or not when mmap failed. As your > original comment, the call of drm_gem_free_mmap_offset() is unnecessary > if mmap offset is created when gem creation because the mmap offset is > removed by drm_gem_object_release() when gem is destroyed - gem should > also be released when mmap failed. > > Ok, let's create mmap offset at gem creation and remove it gem > releasing. Will merge these two patches. > I can't find them from your git. Could you merge them? Thanks. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
