As confirmed by peterz on IRC, this note is obsolete: <peterz> rata: that section is obsolete; CLOCK_THREAD_CPUTIME_ID is good <peterz> rata: CLOCK_PROCESS_CPUTIME_ID is also correct So this patch just removes it. --- man2/clock_getres.2 | 32 -------------------------------- 1 file changed, 32 deletions(-) diff --git a/man2/clock_getres.2 b/man2/clock_getres.2 index 10ecd18..eac97cd 100644 --- a/man2/clock_getres.2 +++ b/man2/clock_getres.2 @@ -218,38 +218,6 @@ indicate that are available. (See also .BR sysconf (3).) -.SH NOTES -.SS Note for SMP systems -The -.B CLOCK_PROCESS_CPUTIME_ID -and -.B CLOCK_THREAD_CPUTIME_ID -clocks are realized on many platforms using timers from the CPUs -(TSC on i386, AR.ITC on Itanium). -These registers may differ between CPUs and as a consequence -these clocks may return -.B bogus results -if a process is migrated to another CPU. -.PP -If the CPUs in an SMP system have different clock sources then -there is no way to maintain a correlation between the timer registers since -each CPU will run at a slightly different frequency. -If that is the case then -.I clock_getcpuclockid(0) -will return -.B ENOENT -to signify this condition. -The two clocks will then be useful only if it -can be ensured that a process stays on a certain CPU. -.PP -The processors in an SMP system do not start all at exactly the same -time and therefore the timer registers are typically running at an offset. -Some architectures include code that attempts to limit these offsets on bootup. -However, the code cannot guarantee to accurately tune the offsets. -Glibc contains no provisions to deal with these offsets (unlike the Linux -Kernel). -Typically these offsets are small and therefore the effects may be -negligible in most cases. .SH BUGS According to POSIX.1-2001, a process with "appropriate privileges" may set the .B CLOCK_PROCESS_CPUTIME_ID -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
