Bug 81396
| Summary: | /proc/cpuinfo contains bogus values for SMP kernels on non-hyperthreaded processors | ||
|---|---|---|---|
| Product: | [Retired] Red Hat Linux | Reporter: | Michael J. Saletnik <michael> |
| Component: | kernel | Assignee: | Arjan van de Ven <arjanv> |
| Status: | CLOSED WONTFIX | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 7.3 | ||
| 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: | 2004-09-30 15:40:22 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: | |||
Thanks for the bug report. However, Red Hat no longer maintains this version of the product. Please upgrade to the latest version and open a new bug if the problem persists. The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, and if you believe this bug is interesting to them, please report the problem in the bug tracker at: http://bugzilla.fedora.us/ |
Description of problem: Red Hat has ported some of the hyperthreading support from the 2.5 to the 2.4 kernels. In particular, code which prints "Physical processor ID" and "Number of siblings" in /proc/cpuinfo has been added as linux-2.4.18-cpuinfo-siblings.patch as of kernel-2.4.18-18.7.x However, although this is #ifdef'd for SMP kernels, if you look at the 2.5 series (arch/i386/kernel/cpu/proc.c) you will see that it also has to be wrapped in an if (cpu_has_ht) test. Otherwise, running on a non-hyperthreaded-cpu SMP system, the physical id and number of siblings will print out uninitialized values, possibly different each time. Version-Release number of selected component (if applicable): kernel-2.4.18-18.7.x and newer How reproducible: Easily Steps to Reproduce: 1. On an SMP system without hyperthreaded cpus: while /bin/true ; do egrep 'Physical|sibling' /proc/cpuinfo ; done Actual results: Physical processor ID : 591210800 Number of siblings : 1 Physical processor ID : 741353507 Number of siblings : 1 etc... Expected results: Nothing at all - this should not be displayed for non-hyperthreaded cpu's. Additional info: