Re: [PATCH v2 2/2] ALSA: set no sound proc fs for reduced memory footprint

[Takashi Iwai <tiwai@suse.de>]

At Wed, 27 May 2015 07:40:24 +0000,
Jie, Yang wrote:
> 
> > -----Original Message-----
> > From: Takashi Iwai [mailto:tiwai@suse.de]
> > Sent: Wednesday, May 27, 2015 3:23 PM
> > To: Jie, Yang
> > Cc: Sudip Mukherjee; broonie@kernel.org; alsa-devel@alsa-project.org;
> > linux-kernel@vger.kernel.org; Girdwood, Liam R; Zhang, Vivian
> > Subject: Re: [PATCH v2 2/2] ALSA: set no sound proc fs for reduced memory
> > footprint
> > 
> > At Wed, 27 May 2015 07:09:24 +0000,
> > Jie, Yang wrote:
> > >
> > > > -----Original Message-----
> > > > From: Takashi Iwai [mailto:tiwai@suse.de]
> > > > Sent: Wednesday, May 27, 2015 2:19 PM
> > > > To: Jie, Yang
> > > > Cc: Sudip Mukherjee; broonie@kernel.org;
> > > > alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org; Girdwood,
> > > > Liam R; Zhang, Vivian
> > > > Subject: Re: [PATCH v2 2/2] ALSA: set no sound proc fs for reduced
> > > > memory footprint
> > > >
> > > > At Wed, 27 May 2015 05:38:01 +0000,
> > > > Jie, Yang wrote:
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Sudip Mukherjee [mailto:sudipm.mukherjee@gmail.com]
> > > > > > Sent: Wednesday, May 27, 2015 12:50 PM
> > > > > > To: Jie, Yang
> > > > > > Cc: tiwai@suse.de; broonie@kernel.org;
> > > > > > alsa-devel@alsa-project.org;
> > > > > > linux- kernel@vger.kernel.org; Girdwood, Liam R; Zhang, Vivian
> > > > > > Subject: Re: [PATCH v2 2/2] ALSA: set no sound proc fs for
> > > > > > reduced memory footprint
> > > > > >
> > > > > > On Tue, May 26, 2015 at 09:13:57PM +0800, Jie Yang wrote:
> > > > > > > Disable sound proc fs, when CONFIG_SND_NO_PROC_FS is
> > selected,
> > > > > > > which can save about 9KB memory size for reducing memory
> > > > > > > footprint
> > > > purpose.
> > > > > > > ---
> > > > > > missing Signed-off-by.
> > > > >
> > > > > Thanks for pointing out.
> > > > >
> > > > > Signed-off-by: Jie Yang <yang.jie@intel.com>
> > > > >
> > > > > Takashi, do I need to resend them?
> > > >
> > > > Yes, but you seen to have missed my first comment.  Here again:
> > >
> > > Sorry about the missing. :)
> > >
> > > >
> > > >
> > ==========================================================
> > > > ======
> > > > > +menuconfig SND_REDUCED_MEMORY_FOOTPRINT
> > > > > +	bool "Reduced Memory Footprint Support"
> > > > > +	default n
> > > > > +	help
> > > > > +	  Say 'Y' to enable Reduced Memory Footprint Support, which may
> > > > > +	  reduce code size and data footprint as much as possible.
> > > >
> > > > I'd like to move this into sound/core.
> > > > Also, the kconfig name appears a bit too lengthy to me.
> > > >
> > ==========================================================
> > > > ======
> > > >
> > > > And, after reading this again, I wonder whether we just take the
> > > > existing CONFIG_EXPERT for allowing the selection of more knobs like
> > > > CONFIG_SND_PROC_FS.
> > > >
> > > > SND_PROC_FS
> > > > 	bool "Sound proc file" if EXPERT
> > >
> > > Sounds good. Then we don't need 'SND_REDUCED_MEMORY_FOOTPRINT'
> > > any more? Or we can keep it as root menu of the set of items, just as
> > below?
> > > (I changed it to SND_SMALL_FOOTPRINT, as your comment above)
> > 
> > I originally thought to select items from SND_SMALL_FOOTPRINT, but this
> > doesn't seem to work.  At least, "de"selecting isn't supported by Kconfig (i.e.
> > set SND_PROC_FS=n when SND_SMALL_FOOTPRINT=y).
> > We may have SND_NO_PROC_FS and select it, but it's too bad.
> > 
> > So, IMO, we can drop SND_SMALL_FOOTPRINT but let users choose each
> > knob when EXPERT=y.
>  
> Firstly, I used sound/Kconfig but not sound/core/Kconfig, because some
> efforts for reducing footprint are based on sound/asoc/(e.g. dapm, dpcm,
> ...).

sound/core/Kconfig defines the core sound components and
configurations, so it's more appropriate.

> Secondly, if we drop SND_SMALL_FOOTPRINT, then we have to add
> several(may up to ~10) knobs under the sound menu(Sound Card Support),
> which looks messy and not neat.

The question is whether we want more selectable knobs.  If you got for
simplicity, SND_PROC_FS shouldn't be selectable either, but just give
SND_SMALL_FOOTPRINT selectable.


Takashi