From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Ahern <dsahern@gmail.com>
Subject: Re: [PATCH net-next 0/9] devlink: Add support for region access
Date: Sat, 31 Mar 2018 11:21:12 -0600
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Cc: "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
        Tariq Toukan <tariqt@mellanox.com>,
        Jiri Pirko <jiri@mellanox.com>
To: Andrew Lunn <andrew@lunn.ch>, Alex Vesker <valex@mellanox.com>
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On 3/31/18 9:53 AM, Andrew Lunn wrote:
>> I want to be able to login to a customer and accessing this snapshot
>> without any previous configuration from the user and not asking for
>> enabling the feature and then waiting for a repro...this will help
>> debugging issues that are hard to reproduce, I don't see any reason
>> to disable this.
> 
> The likely reality is 99.9% of these snapshots will never be seen or
> used. But they take up memory sitting there doing nothing. And if the
> snapshot is 2GB, that is a lot of memory. I expect a system admin
> wants to be able to choose to enable this feature or not, because of
> that memory. You should also consider implementing the memory pressure
> callbacks, so you can discard snapshots, rather than OOM the machine.
> 

That is exactly my point. Nobody wants one rogue device triggering
snapshots, consuming system resources and with no options to disable it.