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Diffstat (limited to 'open_issues/time.mdwn')
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diff --git a/open_issues/time.mdwn b/open_issues/time.mdwn new file mode 100644 index 00000000..ab239aef --- /dev/null +++ b/open_issues/time.mdwn @@ -0,0 +1,69 @@ +[[!meta copyright="Copyright © 2009, 2011 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +[[!tag open_issue_porting]] + +Neither the `time` executable from the GNU time package work completely +correctly, nor does the GNU Bash built-in one. + + tschwinge@flubber:~ $ \time sleep 2 + 0.00user 0.00system 9:38:00elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k + 0inputs+0outputs (0major+0minor)pagefaults 0swaps + tschwinge@flubber:~ $ \time sleep 4 + 0.00user 0.00system 18:50:25elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k + 0inputs+0outputs (0major+0minor)pagefaults 0swaps + tschwinge@flubber:~ $ \time sleep 6 + 0.00user 0.00system 28:00:53elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k + 0inputs+0outputs (0major+0minor)pagefaults 0swaps + tschwinge@flubber:~ $ time sleep 2 + + real 0m2.093s + user 0m0.000s + sys 0m0.011s + tschwinge@flubber:~ $ time sleep 4 + + real 0m4.083s + user 0m0.000s + sys 0m0.010s + tschwinge@flubber:~ $ time sleep 6 + + real 0m6.164s + user 0m0.000s + sys 0m0.010s + +GNU time's *elapsed* value is off by some factor. + + $ \time factor 1111111111111111111 + 1111111111111111111: 1111111111111111111 + 0.00user 0.00system 52:39:24elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k + 0inputs+0outputs (0major+0minor)pagefaults 0swaps + $ time factor 1111111111111111111 + 1111111111111111111: 1111111111111111111 + + real 0m11.424s + user 0m0.000s + sys 0m0.010s + +As above; also here all the running time should be attriuted to *user* time. +This is probably a [[!taglink open_issue_gnumach]]. + + +# 2011-09-02 + +Might want to revisit this, and take Xen [[!tag open_issue_xen]] into account +-- I believe flubber has already been Xenified at that time. + + +## IRC, freenode, #hurd, 2011-09-02 + +While testing some [[performance/IPC_virtual_copy]] performance issues: + + <tschwinge> And I can confirm that with dd if=/dev/zero of=/dev/null bs=4k + running, a parallel sleep 10 takes about 20 s (on strauss). |