[Users] pre-built i686 kernel flavors

Solar Designer solar at openwall.com
Sat Jul 10 18:57:37 EDT 2010


On Sun, Jul 11, 2010 at 02:32:50AM +0400, Kirill Korotaev wrote:
> a. We really had a huge problem in the past with lots of containers on i686 with >>8GB RAM when Normal zone could
> get exhausted due to kernel allocations. So it was not a hack for enterprisy Apps,

I think it was for Red Hat, you just found a different use for it. :-)
IIRC, they primarily cared about the user address space increase from
3 GB to 4 GB (yes, that little thing), whereas you've benefited from
the kernel address space increase.

> but rather a feature allowing
> to increase containers density (due to 3.5Gb Normal zone). Fortunately, all machines support 64bit nowdays and it can be dropped.
> RHEL5 branch will be the last to support it.
> b. Performance impact of -ent kernel is less then 20% on web applications. It's not that bad price taking into account
> that it allows to run  up to 4x times more containers.

Thank you for explaining this.  It makes sense to me now.

Alexander


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