lkml.org 
[lkml]   [2007]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH mm] fix swapoff breakage; however...
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.

Hugh
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-09-17 21:57    [W:0.094 / U:0.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site