Re: PHP performance on Xen domU with mulitple vcpu
Emmanuel Dreyfus <[email protected]>
| Newsgroups | gmane.os.netbsd.devel.kernel |
|---|---|
| Message-ID | <[email protected]> |
On Sun, Apr 06, 2025 at 11:50:37PM +0000, Emmanuel Dreyfus wrote: > I restarted with stock 10.0 XEN3_DOMU kernel to get dtrace working > (it does not), but now the problem seems to have vanished. I have a domU carrying a busy web server. I upgraded vcpus from 1 to 4, and the time keeping bug pops up within a few hours. ntpd gets unable to keep in sync, and clock quickly drift. After 40 minutes of utpime, I already have toublesome outout from the test counting how many time gettimefday() returns the same value. Here is an example for 1000 calls: 227 1747527666.919678 204 1747527666.919679 2 1747527666.925902 38 1747527666.925914 4 1747527666.926081 2 1747527666.926099 2 1747527666.926107 4 1747527666.926120 1 1747527666.926135 2 1747527666.926141 2 1747527666.926151 6 1747527666.926159 1 1747527666.926189 1 1747527666.926194 79 1747527666.926201 425 1747527666.926202 That suggests the bug is easier to reproduce with more vcpus. -- Emmanuel Dreyfus [email protected]