linux-kernel - Re: [PATCH 1/1] staging: rtl8723au: Remove unnecessary OOM message

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Date:	Fri, 06 Mar 2015 14:43:09 -0500
From:	Jes Sorensen <Jes.Sorensen@...hat.com>
To:	Joe Perches <joe@...ches.com>
Cc:	Julia Lawall <julia.lawall@...6.fr>,
	Quentin Lambert <lambert.quentin@...il.com>,
	Larry Finger <Larry.Finger@...inger.net>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	kernel-janitors@...r.kernel.org, linux-wireless@...r.kernel.org,
	devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] staging: rtl8723au: Remove unnecessary OOM message

Joe Perches <joe@...ches.com> writes:
> On Fri, 2015-03-06 at 11:08 -0500, Jes Sorensen wrote:
>> Julia Lawall <julia.lawall@...6.fr> writes:
>> > On Fri, 6 Mar 2015, Jes Sorensen wrote:
>> >> Quentin Lambert <lambert.quentin@...il.com> writes:
>> >> > This patch reduces the kernel size by removing error messages
>> >> > that duplicate
>> >> > the normal OOM message.
>> >> > A simplified version of the semantic patch that finds this problem is as
>> >> > follows: (http://coccinelle.lip6.fr)
>> >> This patch removes useful warnings about what allocation failed. The
>> >> messages removed are NOT duplicate!
>> > Is it really the case that the information can't be reconstructed from the
>> > information generated by kmalloc on failure?  To my understanding there is
>> > a stack trace, and from scanning through the changes I see only one change
>> > per function, so perhaps the stack trace already makes it clear where the
>> > problem occurred?
>> It may be possible to backtrack, but this change just makes it harder.
>> There are tons of real issues to fix in this driver, this patch just
>> increases the risk of patch conflicts for no real gain.
>
> Making the allocation less likely to fail for
> low memory systems is a gain.
>
> The allocation failures themselves are low
> likelihood events.  Determining which specific
> memory allocation failure occurred has near
> nil value.

Joe,

That is bologna, knowing which allocation failed has a lot of value, it
allows the developer to go back and look at the allocation sizes,
parameters applied etc.

This is a classic case of blindly applied script 'fixes' causing more
harm than good.

Jes
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