Bug 122859
| Summary: | slow /md0 raid 5 under smp kernel (ok single, ok smp acpi=off amp=off) | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Robin L <rluiten> |
| Component: | mdadm | Assignee: | Doug Ledford <dledford> |
| Status: | CLOSED WORKSFORME | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | medium | ||
| Version: | rawhide | CC: | len.brown |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i686 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-09-19 18:56:04 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: | |||
Please attach the dmesg and /proc/interrupts from the successful UP kernel, and failing MP kernel. It may be an IOAPIC issue, since that comes along with the SMP kernel. Closing this bug due to inactivity. |
From Bugzilla Helper: User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040206 Firefox/0.8 Description of problem: Hardware is Pentium 4 HT capable 2.8Ghz on Abit IC7 Max3 motherboard. (which is intel 875 chipset) with 1gig of ram. If I boot the smp kernel then hdparm and normal file access to files on /dev/md0 mounted as /raid. Raid is 6 200gig sata drives in raid 5 128k chunk filesystem is ext3 block size is 2048 stride is set to 64. (created with mdadm and started with it) Using default kernels on fc2 test3 release 2.6.5-1.327 and 2.6.5-1.327smp. hdparm -Tt /dev/md0 under smp - is 15-22 megabytes/sec hdparm -Tt /dev/md0 under single cpu - is over 100 megabytes/sec Reading a 3 gigabyte file from /raid shows an equivalent different in performance under the smp and single kernels. hdparm any of the 6 raw drives in the md0 raid. hdparm -Tt /dev/sda1 - gives around 48 megabytes sec in either the smp or the single cpu kernel. It appears just the software raid device is having some sort of problem. I cannot find any errors appearing in the logs (though maybe i just dont know all the places to look). If I boot the smp kernel with acpi=off and apm=off then smp kernel appears to give same sort of performance as single cpu. Version-Release number of selected component (if applicable): mdadm-1.5.0-3 How reproducible: Always Steps to Reproduce: 1. boot smp kernel 2. hdparm -Tt /dev/md0 3. Actual Results: Its much slower in performance than in single cpu kernel or with acpi=off apm=off. Additional info: