* [Bug tapsets/11209] New: Provide an alternative time tapset
@ 2010-01-21 22:36 jistone at redhat dot com
2010-01-26 17:12 ` [Bug tapsets/11209] " fche at redhat dot com
2010-01-26 22:55 ` jistone at redhat dot com
0 siblings, 2 replies; 3+ messages in thread
From: jistone at redhat dot com @ 2010-01-21 22:36 UTC (permalink / raw)
To: systemtap
For most scripts, I think the Epoch time provided by gettimeofday_s() is not
that relevant. Most of the time, all that's needed are relative times from one
event to another, and any time source should be fine.
I suggest creating a new walltime tapset that uses whatever time source is most
convenient/efficient. On newer kernels, an implementation backed by the
kernel's cpu_clock() may be a good choice. Where no better option exists, we
can always fall back to gettimeofday automatically.
--
Summary: Provide an alternative time tapset
Product: systemtap
Version: unspecified
Status: NEW
Severity: enhancement
Priority: P2
Component: tapsets
AssignedTo: systemtap at sources dot redhat dot com
ReportedBy: jistone at redhat dot com
http://sourceware.org/bugzilla/show_bug.cgi?id=11209
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^ permalink raw reply [flat|nested] 3+ messages in thread* [Bug tapsets/11209] Provide an alternative time tapset 2010-01-21 22:36 [Bug tapsets/11209] New: Provide an alternative time tapset jistone at redhat dot com @ 2010-01-26 17:12 ` fche at redhat dot com 2010-01-26 22:55 ` jistone at redhat dot com 1 sibling, 0 replies; 3+ messages in thread From: fche at redhat dot com @ 2010-01-26 17:12 UTC (permalink / raw) To: systemtap ------- Additional Comments From fche at redhat dot com 2010-01-26 17:12 ------- Is cpu_clock() synchronized across cpus? -- http://sourceware.org/bugzilla/show_bug.cgi?id=11209 ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tapsets/11209] Provide an alternative time tapset 2010-01-21 22:36 [Bug tapsets/11209] New: Provide an alternative time tapset jistone at redhat dot com 2010-01-26 17:12 ` [Bug tapsets/11209] " fche at redhat dot com @ 2010-01-26 22:55 ` jistone at redhat dot com 1 sibling, 0 replies; 3+ messages in thread From: jistone at redhat dot com @ 2010-01-26 22:55 UTC (permalink / raw) To: systemtap ------- Additional Comments From jistone at redhat dot com 2010-01-26 22:55 ------- (In reply to comment #1) > Is cpu_clock() synchronized across cpus? At the top of sched_clock.c, it says: * The clock: sched_clock_cpu() is monotonic per cpu, and should be somewhat * consistent between cpus (never more than 2 jiffies difference). We should probably experiment to estimate the practical difference of being "somewhat consistent". (And FWIW, I'm not even sure how close we can assert our current gtod is.) -- http://sourceware.org/bugzilla/show_bug.cgi?id=11209 ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-01-26 22:55 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2010-01-21 22:36 [Bug tapsets/11209] New: Provide an alternative time tapset jistone at redhat dot com 2010-01-26 17:12 ` [Bug tapsets/11209] " fche at redhat dot com 2010-01-26 22:55 ` jistone at redhat dot com
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