Bug 33309
Summary: | [performance] Elevator starvation (regression relative to recent 2.2) | ||
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Product: | [Retired] Red Hat Linux | Reporter: | Ed McKenzie <eem12> |
Component: | kernel | Assignee: | Michael K. Johnson <johnsonm> |
Status: | CLOSED RAWHIDE | QA Contact: | Brock Organ <borgan> |
Severity: | high | Docs Contact: | |
Priority: | medium | ||
Version: | 7.1 | CC: | dnielsen |
Target Milestone: | --- | ||
Target Release: | --- | ||
Hardware: | i386 | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2001-07-03 13:12:16 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Ed McKenzie
2001-03-27 00:14:34 UTC
It's not an elevator bug: I'm pretty sure that this is a VM balancing bug, and yes, it's easily reproducible and obviously needs fixing. 2.4.2-0.1.49 is *much* better overall, but I can still effectively starve the entire system of disk access with a large dd operation. I can't do this on 2.2; even with a dd running, ls -lR in the same directory runs, albeit in spurts. The same test under 2.4 results in ls not doing very much. Followup: it's not just an IDE issue. I also see disk starvation under 2.4.2-2 on an all-SCSI setup. 2 questions: 1) could you tru 2.4.3-5 from rawhide 2) could you use elvtune to change the defaults of the elevator ? (or use a recent snapshot of powertweak (www.powertweak.org) for that) 2.4.3-5 seems no different wrt the elevator, and it seems to have other issues as well. What are suggested fair, low-latency values for elvtune? I couldn't improve things beyond "slightly less starvation..." Upgrading to 2.4.5-0.2.9 didn't improve I/O fairness. 2.4.3-12 also appears to be broken. 2.4.5-10 is also broken wrt dd usage. However, interactivity is somewhat better when operating on large tarballs than earlier RH kernels. Performance seems to be subjectively better in recent (2.4.7, 2.4.8-ac) kernels. *** Bug 42355 has been marked as a duplicate of this bug. *** |