[Dovecot] load increase after upgrade to 2.0.8

[Mark Moseley]

On Thu, Dec 9, 2010 at 4:54 PM, Stan Hoeppner <stan at hardwarefreak.com> wrote:
> Mark Moseley put forth on 12/9/2010 12:18 PM:
>
>> If you at some point upgrade to >2.6.35, I'd be interested to hear if
>> the load skyrockets on you. I also get the impression that the load
>> average calculation in these recent kernels is 'touchier' than in
>> pre-2.6.35.
>
> This thread may be of value in relation to this issue:
>
> http://groups.google.com/group/linux.kernel/browse_thread/thread/eb5cb488b7404dd2/0c954e88d2f20e56
>
> It seems there are some load issues regarding recent Linux kernels, from
> 2.6.34 (maybe earlier?) on up.  The commit of the patch to fix it was
> Dec 8th--yesterday.  So it'll be a while before distros get this patch out.

Glad you brought up that thread. I've seen it before but not any time
lately (and certainly not since 2 days ago!). Hopefully that'll be in
2.6.37, instead of not till 2.6.38 (or that I can patch it into
2.6.36.2). I roll my own kernels, so no need to wait on distros.


> However, this still doesn't seem to explain Ralf's issue, where the
> kernel stays the same, but the Dovecot version changes, with 2.0.x
> causing the high load and 1.2.x being normal.  Maybe 2.0.x simply causes
> this bug to manifest itself more loudly?
>
> This Linux kernel bug doesn't explain the high load reported with 2.0.x
> on FreeBSD either.  But it is obviously somewhat at play for people
> running these kernels versions and 2.0.x.  To what degree it adds to the
> load I cannot say.

Yeah, my comment on the kernel thing was just in reply to one of Cor's
3 debugging tracks, 1 of which was to try upgrading the kernel. I
figured I should mention the load issue if he might be upgrading to
the latest/greatest, since it could make things worse (or make things
*look* worse).