Re: [PATCH -next] powerpc/powernv: Fix debugfs_simple_attr.cocci warnings

2018-10-08 Thread Michael Ellerman
YueHaibing  writes:
> Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
> for debugfs files.
>
> Semantic patch information:
> Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
> imposes some significant overhead as compared to
> DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().

Sorry this isn't detailed enough for me to actually understand the
pros/cons of this patch.

Perhaps I'm expected to know it, but I don't.

I had a look at what each macro produces and it wasn't obvious to me
what the benefit is.

cheers

> Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
>
> Signed-off-by: YueHaibing 
> ---
>  arch/powerpc/platforms/powernv/memtrace.c | 8 
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/memtrace.c 
> b/arch/powerpc/platforms/powernv/memtrace.c
> index 84d038e..0cb6548 100644
> --- a/arch/powerpc/platforms/powernv/memtrace.c
> +++ b/arch/powerpc/platforms/powernv/memtrace.c
> @@ -311,8 +311,8 @@ static int memtrace_enable_get(void *data, u64 *val)
>   return 0;
>  }
>  
> -DEFINE_SIMPLE_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get,
> - memtrace_enable_set, "0x%016llx\n");
> +DEFINE_DEBUGFS_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get,
> +  memtrace_enable_set, "0x%016llx\n");
>  
>  static int memtrace_init(void)
>  {
> @@ -321,8 +321,8 @@ static int memtrace_init(void)
>   if (!memtrace_debugfs_dir)
>   return -1;
>  
> - debugfs_create_file("enable", 0600, memtrace_debugfs_dir,
> - NULL, _init_fops);
> + debugfs_create_file_unsafe("enable", 0600, memtrace_debugfs_dir, NULL,
> +_init_fops);
>  
>   return 0;
>  }


[PATCH -next] powerpc/powernv: Fix debugfs_simple_attr.cocci warnings

2018-10-05 Thread YueHaibing
Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().

Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci

Signed-off-by: YueHaibing 
---
 arch/powerpc/platforms/powernv/memtrace.c | 8 
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c 
b/arch/powerpc/platforms/powernv/memtrace.c
index 84d038e..0cb6548 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -311,8 +311,8 @@ static int memtrace_enable_get(void *data, u64 *val)
return 0;
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get,
-   memtrace_enable_set, "0x%016llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get,
+memtrace_enable_set, "0x%016llx\n");
 
 static int memtrace_init(void)
 {
@@ -321,8 +321,8 @@ static int memtrace_init(void)
if (!memtrace_debugfs_dir)
return -1;
 
-   debugfs_create_file("enable", 0600, memtrace_debugfs_dir,
-   NULL, _init_fops);
+   debugfs_create_file_unsafe("enable", 0600, memtrace_debugfs_dir, NULL,
+  _init_fops);
 
return 0;
 }