Opened 16 years ago
Closed 15 years ago
#2869 closed defect (fixed)
Debian host, Debian guest: rdtsc goes backwards -> fixed in SVN/3.0.6
| Reported by: | Markus Laker | Owned by: | |
|---|---|---|---|
| Component: | VMM/HWACCM | Version: | VirtualBox 3.0.4 |
| Keywords: | rdtsc backwards | Cc: | |
| Guest type: | Linux | Host type: | Linux |
Description
On Debian Lenny on a real PC, the attached program (rdtsc.cpp) works as expected. On Debian Lenny in VirtualBox 2.1.0 on Debian Lenny, the same program aborts after a few hundred thousand iterations, showing that rdtsc occasionally goes backwards. I've attached some sample output in output.txt.
If we ignore wrapping, rdtsc should only increase; it should never decrease.
Attachments (3)
Change History (9)
by , 16 years ago
by , 16 years ago
| Attachment: | output.txt added |
|---|
Sample output when this program is run inside VirtualBox
comment:2 by , 16 years ago
| Component: | other → VMM |
|---|
comment:3 by , 16 years ago
| Component: | VMM → VMM/HWACCM |
|---|
Problem reproduced. Does not happen if VT-x / AMD-V is disabled.
comment:4 by , 15 years ago
| Summary: | Debian host, Debian guest: rdtsc goes backwards → Debian host, Debian guest: rdtsc goes backwards -> fixed in SVN/3.0.6 |
|---|
comment:5 by , 15 years ago
| Version: | VirtualBox 2.1.0 → VirtualBox 3.0.4 |
|---|
comment:6 by , 15 years ago
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
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Demonstration program, to be compiled with G++