Hi  greg,

I am sorry,
I make a mistake ,
You are right ,
https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/drivers/usb/gadget/f_mass_storage.c?h=master#n2724

this one should not changed to use vmalloc,
the buffer will be used by DMA，

others should be safe to change:

https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/sound/soc/soc-core.c?h=master#n3772

https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/net/netfilter/nf_conntrack_ftp.c?h=master#n603
https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/net/netfilter/nf_conntrack_h323_main.c?h=master#n1849
https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/net/netfilter/nf_conntrack_irc.c?h=master#n247
https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/net/netfilter/nf_conntrack_sane.c?h=master#n195

https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/drivers/input/evdev.c?h=master#n403


Thanks 
-----Original Message-----
From: 'gregkh@linuxfoundation.org' [mailto:gregkh@linuxfoundation.org] 
Sent: Saturday, March 01, 2014 12:33 AM
To: Wang, Yalin
Cc: 'Huang Shijie'; 'linux-kernel@vger.kernel.org'; 'linux-arm-msm@vger.kernel.org'; 'linux-arm-kernel@lists.infradead.org'; 'linux-input@vger.kernel.org'; 'balbi@ti.com'; 'lrg@ti.com'; 'broonie@opensource.wolfsonmicro.com'; 'perex@perex.cz'; 'tiwai@suse.de'; 'pablo@netfilter.org'; 'kaber@trash.net'; 'davem@davemloft.net'; 'rostedt@goodmis.org'; 'fweisbec@gmail.com'; 'mingo@redhat.com'; 'dmitry.torokhov@gmail.com'; 'rydberg@euromail.se'; 'linux-usb@vger.kernel.org'; 'alsa-devel@alsa-project.org'; 'netfilter-devel@vger.kernel.org'; 'netfilter@vger.kernel.org'; 'coreteam@netfilter.org'; 'netdev@vger.kernel.org'
Subject: Re: change kmalloc into vmalloc for large memory allocations

On Fri, Feb 28, 2014 at 05:20:08PM +0800, Wang, Yalin wrote:

Hi


Yeah,
Dma buffer must be allocated by kmalloc,

But the modules I list should can all be changed to use vmalloc, 
because the buffer is only used by software, Not by any hardware .

Are you sure about that?  The USB gadget driver needs DMA memory from what I can tell, have you tried your change out on a system that does not allow the USB controller to access non-DMA memory?

And I agree with Steve, just fix the individual drivers, don't do a "hidden" change of where the memory is allocated from, that's not a good idea and will cause problems later.

greg k-h