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From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Wed, 24 Oct 2012 20:56:45 -0400
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Subject: Re: [PATCH] add some drop_caches documentation and info messsge
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>, Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.cz>, linux-mm@kvack.org,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        LKML <linux-kernel@vger.kernel.org>
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On Wed, Oct 24, 2012 at 6:57 PM, Dave Hansen <dave@linux.vnet.ibm.com> wrote:
> On 10/24/2012 03:48 PM, Borislav Petkov wrote:
>> On Wed, Oct 24, 2012 at 02:18:38PM -0700, Dave Hansen wrote:
>>> Sounds fairly valid to me. But, it's also one that would not be harmed
>>> or disrupted in any way because of a single additional printk() during
>>> each suspend-to-disk operation.
>>
>> back to the drop_caches patch. How about we hide the drop_caches
>> interface behind some mm debugging option in "Kernel Hacking"? Assuming
>> we don't need it otherwise on production kernels. Probably make it
>> depend on CONFIG_DEBUG_VM like CONFIG_DEBUG_VM_RB or so.
>>
>> And then also add it to /proc/vmstat, in addition.
>
> That effectively means removing it from the kernel since distros ship
> with those config options off.  We don't want to do that since there
> _are_ valid, occasional uses like benchmarking that we want to be
> consistent.

Agreed. we don't want to remove valid interface never.