I use to measure time using the getrusage() function in my C/C++ code and, suddenly, perfectly working code with previous releases of the kernel did not work anymore with kernel 2.6.32-25 ; The bug extends to the shell command "time". Its effect is that user time cannot pass a given threshold, around 261.8s, the rest of the running time of a process being counted as system time.
ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-headers-2.6.32-25 2.6.32-25.45
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.32-24.43-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
Architecture: i386
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: jermann-c 2110 F.... pulseaudio
CRDA: Error: [Errno 2] Aucun fichier ou dossier de ce type
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xfe9fc000 irq 21'
Mixer name : 'SigmaTel STAC9205'
Components : 'HDA:838476a0,102801f9,00100204 HDA:14f12c06,14f1000f,00100000'
Controls : 19
Simple ctrls : 11
Date: Mon Nov 15 11:08:30 2010
HibernationDevice: RESUME=UUID=8d4f1ec4-764d-4ad5-a6b1-cad44b9861b0
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
MachineType: Dell Inc. Latitude D630
PackageArchitecture: all
PccardctlIdent:
Socket 0:
no product info available
PccardctlStatus:
Socket 0:
no card
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-24-generic root=UUID=30ea42a4-6eca-4b4f-bc65-2b4e23e79ab4 ro quiet splash
ProcEnviron:
PATH=(custom, user)
LANG=fr_FR.utf8
SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.34.1
SourcePackage: linux
dmi.bios.date: 06/20/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A12
dmi.board.name: 0KU184
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA12:bd06/20/2008:svnDellInc.:pnLatitudeD630:pvr:rvnDellInc.:rn0KU184:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude D630
dmi.sys.vendor: Dell Inc.
Quoting from:
man time
"...
ACCURACY
The elapsed time is not collected atomically with the execution of the
program; as a result, in bizarre circumstances (if the time command
gets stopped or swapped out in between when the program being timed
exits and when time calculates how long it took to run), it could be
much larger than the actual execution time.
When the running time of a command is very nearly zero, some values
(e.g., the percentage of CPU used) may be reported as either zero
(which is wrong) or a question mark.
Most information shown by time is derived from the wait3(2) system
call. The numbers are only as good as those returned by wait3(2). On
systems that do not have a wait3(2) call that returns status
information, the times(2) system call is used instead. However, it
provides much less information than wait3(2), so on those systems time
reports the majority of the resources as zero.
The `%I' and `%O' values are allegedly only `real' input and output and
do not include those supplied by caching devices. The meaning of
`real' I/O reported by `%I' and `%O' may be muddled for workstations,
especially diskless ones.
..."