Bug 177809
| Summary: | glibc-headers uses SCHED_OTHER while kernel uses SCHED_NORMAL | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Oleg Goldshmidt <pub> |
| Component: | glibc | Assignee: | Jakub Jelinek <jakub> |
| Status: | CLOSED NOTABUG | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 4 | ||
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-01-14 16:09:40 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: | |||
SCHED_OTHER is the name POSIX requires: http://www.opengroup.org/onlinepubs/009695399/basedefs/sched.h.html so glibc headers must not change. |
Description of problem: The <bits/sched.h> from glibc, and the man pages at least for sched_{get,set}scheduler(2) use SCHED_OTHER for the default process scheduling policy. In the kernel (<linux/sched.h> in 2.6.14, 2.6.15 from Fedora updates) the symbolic name was changed to SCHED_NORMAL. This does not cause a real problem yet because in both cases the macro is expanded to 0. However, it is inconsistent, confusing, and potentially dangerous. It should be trivial to fix in every single case, but I think RedHat/Fedora should decide how to approach it system-wide. There may be other apps (e.g. mozilla) that use SCHED_OTHER as well. I suppose userspace should follow the kernel on this. Version-Release number of selected components (on my system): Fedora Core release 4 (Stentz) Linux 2.6.15-1.1823_FC4smp x86_64 kernel-2.6.14-1.1656_FC4 kernel-2.6.15-1.1823_FC4 glibc-headers-2.3.5-10.3 man-pages-1.67-8 How reproducible: Looking at the code and man pages. Steps to Reproduce: 1. grep (or look at) the kernel sources, namely <linux/sched.h> for SCHED_(OTHER|NORMAL) 2. grep the system headers, namely <bits/sched.h> for same 3. look at (or grep) the relevant man pages (sched_getscheduler(2), sched_setscheduler(2)) Actual results: $ egrep -A2 "^#define[ \t]+SCHED_(OTHER|NORMAL)" /usr/src/linux-2.6.15/include/linux/sched.h #define SCHED_NORMAL 0 #define SCHED_FIFO 1 #define SCHED_RR 2 $ egrep -A2 "^#define[ \t]+SCHED_(OTHER|NORMAL)" /usr/src/linux-2.6.14/include/linux/sched.h #define SCHED_NORMAL 0 #define SCHED_FIFO 1 #define SCHED_RR 2 $ egrep -A2 "^#define[ \t]+SCHED_(OTHER|NORMAL)" /usr/include/bits/sched.h #define SCHED_OTHER 0 #define SCHED_FIFO 1 #define SCHED_RR 2 $ man sched_getscheduler | col -b | egrep "SCHED_(OTHER|NORMAL)" SCHED_RR, and SCHED_OTHER; their respective semantics are described SCHED_OTHER is the default universal time-sharing scheduler policy used uled with SCHED_OTHER must be assigned the static priority 0, processes preempt immediately any currently running normal SCHED_OTHER process. SCHED_OTHER: Default Linux time-sharing scheduling SCHED_OTHER can only be used at static priority 0. SCHED_OTHER is the fair progress among all SCHED_OTHER processes. Expected results: SCHED_NORMAL used instead of SCHED_OTHER, consistently with the kernel Additional info: I queried the Bugzilla for SCHED_NORMAL in comments, found nothing.