Ubuntu on EC2

Bug #574910
Comment #83

Comment 83 for bug 574910

Revision history for this message

John Johansen (jjohansen) wrote on 2010-09-08:

#83

Alex,

I appreciate both your frustration and your desire to help, the Lucid kernel has seen literally hundreds of patches since release (see https://edge.launchpad.net/ubuntu/+source/linux/2.6.32-25.43) for just the latest round of updates for the proposed kernel and more are already on the way.

The linux task on this bug has not been closed, and is not being ignored. In general the kernel team tries to get bugs filed separately and then merge them/mark them as duplicates after the fact. This is done, do to the nature of kernel bugs, where just because a bug has similar symptoms they may not be related. Eg. graphics issue on intel hardware are most likely different than bugs on ati hardware, even if they exhibit many of the same symptoms.

I asked that a new bug be opened, as the issues you are experiencing seem to be different than the bug I had fixed, which specifically dealt with a load calculation issue in the EC2 kernel, that is not present in the -generic or -server kernels. When this bug was opened it was focused on EC2 which runs a kernel that is quite different than the rest of Ubuntu, so generally bugs against EC2 are handled somewhat separately from the rest of the Lucid kernel (this will change in the Maverick kernel).

The fact is that there is more than one issue affecting load average on Lucid, and dealing with them in one meta bug just isn't effective. What I wanted to do was split specific issues out so that they can be tracked independently. This is of course difficult to do when the bugs symptoms are high load.

As per specific load problems, there are several issues that have affected Lucid, and the upstream kernels (its not just Ubuntu). There have been the high number of wake ups from the load balancing tick, there has been the write back issue, there is an update to how load is computed from upstream that fixes a bug where load was under reported in older kernels, all newer kernels have this patch and so it should be expected that there are higher loads reported on newer kernels.

What isn't expected is spiraling out of control loads, extremely high loads on an idle systems, or phantom loads. We want to address all issues.

Alex,

The linux task on this bug has not been closed, and is not being ignored.  In general the kernel team tries to get bugs filed separately and then merge them/mark them as duplicates after the fact.  This is done, do to the nature of kernel bugs, where just because a bug has similar symptoms they may not be related.  Eg. graphics issue on intel hardware are most likely different than bugs on ati hardware, even if they exhibit many of the same symptoms.

I asked that a new bug be opened, as the issues you are experiencing seem to be different than the bug I had fixed, which specifically dealt with a load calculation issue in the EC2 kernel, that is not present in the -generic or -server kernels.  When this bug was opened it was focused on EC2 which runs a kernel that is quite different than the rest of Ubuntu, so generally bugs against EC2 are handled somewhat separately from the rest of the Lucid kernel (this will change in the Maverick kernel).

The fact is that there is more than one issue affecting load average on Lucid, and dealing with them in one meta bug just isn't effective.  What I wanted to do was split specific issues out so that they can be tracked independently.  This is of course difficult to do when the bugs symptoms are high load.

As per specific load problems, there are several issues that have affected Lucid, and the upstream kernels (its not just Ubuntu).  There have been the high number of wake ups from the load balancing tick, there has been the write back issue, there is an update to how load is computed from upstream that fixes a bug where load was under reported in older kernels, all newer kernels have this patch and so it should be expected that there are higher loads reported on newer kernels.

What isn't expected is spiraling out of control loads, extremely high loads on an idle systems, or phantom loads.  We want to address all issues.