From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jingoo Han <jg1.han@samsung.com>
Subject: Re: [PATCH 5/9] pwm: spear: Remove unnecessary OOM messages
Date: Mon, 03 Mar 2014 10:14:22 +0900
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To: 'Viresh Kumar' <viresh.kumar@linaro.org>, 'Joe Perches' <joe@perches.com>
Cc: 'Thierry Reding' <thierry.reding@gmail.com>, linux-pwm@vger.kernel.org, 'Andrew Morton' <akpm@linux-foundation.org>, 'Laurent Pinchart' <laurent.pinchart@ideasonboard.com>, 'Dan Carpenter' <dan.carpenter@oracle.com>, 'Jingoo Han' <jg1.han@samsung.com>

On Wednesday, February 26, 2014 3:26 PM, Viresh Kumar wrote:
> On 26 February 2014 10:49, Joe Perches <joe@perches.com> wrote:
> > Look at warn_alloc_failed() in mm/page_alloc.c
> 
> Okay, there is a print there. But I am not able to reach to this routine
> from devm_kzalloc().
> 
> devm_kzalloc() <linux/device.h>
> devm_kmalloc() <drivers/base/devres.c>
> alloc_dr() <drivers/base/devres.c>
> kmalloc_track_caller() <linux/slab.h>
> __kmalloc_track_caller() <mm/slab,slub/slob.c> Taking slab as example:
> __do_kmalloc() <mm/slab.c>

(+CC Laurent Pinchart, Dan Carpenter)

Right, I also cannot find that warn_alloc_failed() is called, during 
devm_kzalloc().

However, in the case of vmalloc(), warn_alloc_failed() is called
as below.

./mm/vmalloc.c
vmalloc()
__vmalloc_node_flags()
__vmalloc_node()
__vmalloc_node_range()

./mm/page_alloc.c
warn_alloc_failed()

> ...
> 
> I can see cases where NULL is returned after above paths and the function
> you mentioned wasn't there. So, I am not sure that we will get a print for sure
> for any error that might occur from devm_kzalloc().

I guess that slab_out_of_memory() <./mm/slub.c> may print it for any errors.
But, I am not sure. :-(

Joe Perches,
Would you confirm this?

Best regards,
Jingoo Han