Messages in this thread | | | Subject | Re: [Outreachy kernel] [PATCH] drm/amdgpu: use DEFINE_DEBUGFS_ATTRIBUTE with debugfs_create_file_unsafe() | From | Christian König <> | Date | Fri, 30 Oct 2020 09:00:04 +0100 |
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Am 30.10.20 um 08:57 schrieb Deepak R Varma: > On Fri, Oct 30, 2020 at 08:11:20AM +0100, Greg KH wrote: >> On Fri, Oct 30, 2020 at 08:52:45AM +0530, Deepak R Varma wrote: >>> Using DEFINE_DEBUGFS_ATTRIBUTE macro with debugfs_create_file_unsafe() >>> function in place of the debugfs_create_file() function will make the >>> file operation struct "reset" aware of the file's lifetime. Additional >>> details here: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.archive.carbon60.com%2Flinux%2Fkernel%2F2369498&data=04%7C01%7Cchristian.koenig%40amd.com%7Cddd7a6ac8164415a639708d87ca97004%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637396414464384011%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=o6GOHvMxNMuOPlC4nhDyURCHBLqfQZhYQq%2BiIMt3D3s%3D&reserved=0 >>> >>> Issue reported by Coccinelle script: >>> scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci >>> >>> Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com> >>> --- >>> Please Note: This is a Outreachy project task patch. >>> >>> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 20 ++++++++++---------- >>> 1 file changed, 10 insertions(+), 10 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c >>> index 2d125b8b15ee..f076b1ba7319 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c >>> @@ -1551,29 +1551,29 @@ static int amdgpu_debugfs_sclk_set(void *data, u64 val) >>> return 0; >>> } >>> >>> -DEFINE_SIMPLE_ATTRIBUTE(fops_ib_preempt, NULL, >>> - amdgpu_debugfs_ib_preempt, "%llu\n"); >>> +DEFINE_DEBUGFS_ATTRIBUTE(fops_ib_preempt, NULL, >>> + amdgpu_debugfs_ib_preempt, "%llu\n"); >> Are you sure this is ok? Do these devices need this additional >> "protection"? Do they have the problem that these macros were written >> for? >> >> Same for the other patches you just submitted here, I think you need to >> somehow "prove" that these changes are necessary, checkpatch isn't able >> to determine this all the time. > Hi Greg, > Based on my understanding, the current function debugfs_create_file() > adds an overhead of lifetime managing proxy for such fop structs. This > should be applicable to these set of drivers as well. Hence I think this > change will be useful.
Well since this is only created once per device instance I don't really care about this little overhead.
But what exactly is debugfs doing or not doing here?
Regards, Christian.
> > I will wait for comments from other experts for driver specific > consideration / behavior. > > Thanks, > drv > > >> thanks, >> >> greg k-h
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