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Diffstat (limited to 'results/classifier/accel-gemma3:12b/vmm/899140')
| -rw-r--r-- | results/classifier/accel-gemma3:12b/vmm/899140 | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/results/classifier/accel-gemma3:12b/vmm/899140 b/results/classifier/accel-gemma3:12b/vmm/899140 new file mode 100644 index 00000000..685a5f4b --- /dev/null +++ b/results/classifier/accel-gemma3:12b/vmm/899140 @@ -0,0 +1,25 @@ + +Problem with Linux Kernel Traffic Control + +Hi, + +The two last main versions of QEMU (0.15 and 1.0) have an important problem when running on a Linux distribution which running itself a Traffic Control (TC) instance. +Indeed, when TC is configured with a Token Bucket Filter (TBF) with a particular rate, the effective rate is very slower than the desired one. + +For instance, lets consider the following configuration : + +# tc qdisc add dev eth0 root tbf rate 20mbit burst 20k latency 50ms + +The effective rate will be about 100kbit/s ! (verified with iperf) +I've encountered this problem on versions 0.15 and 1.0 but not with the 0.14... +In the 0.14, we have a rate of 19.2 mbit/s which is quiet normal. + +I've done the experimentation on several hosts : + +- Debian 32bit core i7, 4GB RAM +- Debian 64bit core i7, 8GB RAM +- 3 different high performance servers : Ubuntu 64 bits, 48 AMD Opteron, 128GB of RAM + +The problem is always the same... The problem is also seen with a Class Based Queuing (CBQ) in TC. + +Thanks \ No newline at end of file |