Messages in this thread | | | Date | Mon, 17 Sep 2007 20:51:05 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: [PATCH mm] fix swapoff breakage; however... |
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On Tue, 18 Sep 2007, Balbir Singh wrote: > Hugh Dickins wrote: > > More fundamentally, it looks like any container brought over its limit in > > unuse_pte will abort swapoff: that doesn't doesn't seem "contained" to me. > > Maybe unuse_pte should just let containers go over their limits without > > error? Or swap should be counted along with RSS? Needs reconsideration. > > Thanks, for the catching this. There are three possible solutions > > 1. Account each RSS page with a probable swap cache page, double > the RSS accounting to ensure that swapoff will not fail. > 2. Account for the RSS page just once, do not account swap cache > pages
Neither of those makes sense to me, but I may be misunderstanding.
What would make sense is (what I meant when I said swap counted along with RSS) not to count pages out and back in as they are go out to swap and back in, just keep count of instantiated pages
I say "make sense" meaning that the numbers could be properly accounted; but it may well be unpalatable to treat fast RAM as equal to slow swap.
> 3. Follow your suggestion and let containers go over their limits > without error > > With the current approach, a container over it's limit will not > be able to call swapoff successfully, is that bad?
That's not so bad. What's bad is that anyone else with the CAP_SYS_ADMIN to swapoff is liable to be prevented by containers going over their limits.
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