[PATCH] perf: remove orphan DEBUG_PERF_USE_VMALLOC

[PATCH] perf: remove orphan DEBUG_PERF_USE_VMALLOC

[Vineet Gupta]

This doesn't seem to be used anywhere

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 init/Kconfig | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index cac3f096050d..934a61f6e2cc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1707,19 +1707,6 @@ config PERF_EVENTS
 
 	  Say Y if unsure.
 
-config DEBUG_PERF_USE_VMALLOC
-	default n
-	bool "Debug: use vmalloc to back perf mmap() buffers"
-	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
-	select PERF_USE_VMALLOC
-	help
-	 Use vmalloc memory to back perf mmap() buffers.
-
-	 Mostly useful for debugging the vmalloc code on platforms
-	 that don't require it.
-
-	 Say N if unsure.
-
 endmenu
 
 config VM_EVENT_COUNTERS
-- 
2.7.4

Re: [PATCH] perf: remove orphan DEBUG_PERF_USE_VMALLOC

[Kim Phillips]

On Tue, 27 Sep 2016 07:53:56 -0700
Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote:

> This doesn't seem to be used anywhere

I thought so too, until I got this response for an equivalent patch:

https://lkml.org/lkml/2016/8/31/53

Kim

Re: [PATCH] perf: remove orphan DEBUG_PERF_USE_VMALLOC

[Vineet Gupta]

On 09/27/2016 09:37 AM, Kim Phillips wrote:
> On Tue, 27 Sep 2016 07:53:56 -0700
> Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote:
> 
>> > This doesn't seem to be used anywhere
> I thought so too, until I got this response for an equivalent patch:
> 
> https://lkml.org/lkml/2016/8/31/53

So this is some sort of "developer shortcut" to quickly enable 2 options with one
option. Purpose seems dubious to me ! It would still be possible to enable vmalloc
backed mmap on x86 by simply enabling that option from Kconfig.

-Vineet

Re: [PATCH] perf: remove orphan DEBUG_PERF_USE_VMALLOC

[Peter Zijlstra]

On Tue, Sep 27, 2016 at 09:51:35AM -0700, Vineet Gupta wrote:
> On 09/27/2016 09:37 AM, Kim Phillips wrote:
> > On Tue, 27 Sep 2016 07:53:56 -0700
> > Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote:
> > 
> >> > This doesn't seem to be used anywhere
> > I thought so too, until I got this response for an equivalent patch:
> > 
> > https://lkml.org/lkml/2016/8/31/53
> 
> So this is some sort of "developer shortcut" to quickly enable 2 options with one
> option. Purpose seems dubious to me ! It would still be possible to enable vmalloc
> backed mmap on x86 by simply enabling that option from Kconfig.

PERF_USE_VMALLOC is not a user selectable option. Also
DEBUG_PERF_USE_VMALLOC clearly indicates its a _DEBUG_ option. Heck,
even the help text says what its for.