Displaying 3 results from an estimated 3 matches for "ptsrc_lapic".
2008 Oct 28
2
late lapic timer interrupts for hvm guest
...pt->scheduled = NOW() + period;
/*
* Offset LAPIC ticks from other timer ticks. Otherwise guests which use
* LAPIC ticks for process accounting can see long sequences of process
* ticks incorrectly accounted to interrupt processing.
*/
if ( pt->source == PTSRC_lapic )
pt->scheduled += period >> 1;
We have ported our mainframe OS BS2000 to x86_64/XEN and we are using the
lapic timer as the main timer interrupt source (one shot mode). Finally I''ve
found the above coding which seems to be the root cause of late interrupts.
I think the...
2009 Feb 09
4
Align periodic vpts to reduce timer interrupts and save power
...below:
pt->scheduled = NOW() + delta;
/*
* Offset LAPIC ticks from other timer ticks. Otherwise guests which use
* LAPIC ticks for process accounting can see long sequences of process
* ticks incorrectly accounted to interrupt processing.
*/
if ( pt->source == PTSRC_lapic )
pt->scheduled += delta >> 1;
But I don''t think this way can really reach the offset purpose, because the additional (delta >> 1) can''t prevent other timers created in other time to expires right before lapic ticks.
Will it really bring issues if vlapic t...
2012 Aug 07
6
Big Bug:Time in VM running on xen goes slower
Dear all:
I have found a big bug on xen concerning time virtualization. Please let me show you the whole process:
1 Phenomenon
when I run a JVM based program in IE browser in my Virtual Machine, I have found clearly that time at the right bottom corner in my VM gets more slower and slower.
I studied the bug deeply, and found something below.
2 Xen
vmx_vmexit_handler --> ......... -->