[lkml]   [2009]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] CPU hard limits
On Fri, Jun 5, 2009 at 2:27 AM, Bharata B Rao<> wrote:
>> Suppose 10 cgroups each want 10% of the machine's CPU. We can just
>> give each cgroup an equal share, and they're guaranteed 10% if they
>> try to use it; if they don't use it, other cgroups can get access to
>> the idle cycles.
> Now if 11th group with same shares comes in, then each group will now
> get 9% of CPU and that 10% guarantee breaks.

So you're trying to guarantee 11 cgroups that they can each get 10% of
the CPU? That's called over-committing, and while there's nothing
wrong with doing that if you're confident that they'll not al need
their 10% at the same time, there's no way to *guarantee* them all
10%. You can guarantee them all 9% and hope the extra 1% is spare for
those that need it (over-committing), or you can guarantee 10 of them
10% and give the last one 0 shares.

How would you propose to guarantee 11 cgroups each 10% of the CPU
using hard limits?


 \ /
  Last update: 2009-06-05 11:35    [W:0.154 / U:1.736 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site