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Subject: Re: [PATCH] mm/swap: add function get_total_swap_pages to expose
 total_swap_pages
To:     Michal Hocko <mhocko@kernel.org>
Cc:     "He, Roger" <Hongbo.He@amd.com>,
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From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
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Date:   Tue, 30 Jan 2018 13:52:16 +0100
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Am 30.01.2018 um 13:28 schrieb Michal Hocko:
> I do think you should completely ignore the size of the swap space. IMHO
> you should forbid further allocations when your current buffer storage
> cannot be reclaimed. So you need some form of feedback mechanism that
> would tell you: "Your buffers have grown too much".

Yeah well, that is exactly what we are trying to do here.

> If you cannot do
> that then simply assume that you cannot swap at all rather than rely on
> having some portion of it for yourself. There are many other users of
> memory outside of your subsystem. Any scaling based on the 50% of resource
> belonging to me is simply broken.

Our intention is not reserve 50% of resources to TTM, but rather allow 
TTM to abort when more than 50% of all resources are used up.

Rogers initial implementation didn't looked like that, but that is just 
a minor mistake we can fix.

Regards,
Christian.