Re: [PATCH] 9p: remove CONFIG_NET_9P_DEBUG option

Eric Van Hensbergen
2011-08-10T12:25:19Z

On Wed, Aug 10, 2011 at 4:13 AM, Aneesh Kumar K.V
<aneesh.kumar@linux.vnet.ibm.com> wrote:
>
> On Mon,  1 Aug 2011 07:14:44 -0500, Alex Ray <alexjray.ncsu@gmail.com> wrote:
>> Remove the CONFIG_NET_9P_DEBUG option, used to completely remove logging
>> functionality from v9fs.  Logging is (already) controlled with the
>> run-time debug= option, this gets rid of the compile-time option (which
>> was being misunderstood and misused).
>>
>> Signed-off-by: Alex Ray <ajray@ncsu.edu>
>
> I see this merged to for-next.  Do we know whether enabling debug always have a
> performance impact ?.
>

No clue, but without any debug it makes it impossible for user's to
generate reasonable bug reports. If I understand the tracepoint
collection facility correctly, it incurs exactly the same overhead as
a DPRINT when the debug mount option is set to 0 (although tracepoints
are much lower overhead when actually collecting). Now, one could
make a case that we have too many DPRINT and need to cut back, but if
that's the case, let's just get around to it and cleanup a bit.

All that being said, I welcome anyone to send me performance with and
without CONFIG_NET_9P_DEBUG turned on to convince me differently.

-eric