Mahendra Kutare
2010-Jul-25 20:33 UTC
[Xen-devel] How to read the xen format file and the generated trace content ?
Hi All, I am trying to understand the format file which comes with too/xentrace/formats. If anyone can help in understanding the following, that will be great - Take for example - 0x0002800e CPU%(cpu)d %(tsc)d (+%(reltsc)8d) switch_infprev [ old_domid = 0x%(1)08x, runtime = %(2)d ] 0x0002800f CPU%(cpu)d %(tsc)d (+%(reltsc)8d) switch_infnext [ new_domid = 0x%(1)08x, time = %(2)d, r_time = %(3)d ] In the above format rule, 1. Can anyone point me to the source code that populates the cpu and tsc using xentrace data ? 2. In the above, I understand 1, 2 and 3 means first, second and third field from the TRACE but what does the whole field description means i.e. 0x%(1)08x apart from the fact that it represents hexadecimal value for DOM IDs. If above represents DOM ID values then from the trace data generated like this - CPU0 7997860846654673 (+ 4133) switch_infprev [ old_domid 0x00007fff, runtime = 79935 ] CPU0 7997860846655190 (+ 517) switch_infnext [ new_domid 0x00000000, time = 3889, r_time = 30000000 ] old_domid = 0x00007fff represents 32767 for some some DOM ID. There is no domain which has been assigned the 32767 id or for that matter DOM0. new_domid = 0x00000000 represents 0 which is clearly the DOM0 id. So what is this old_domid value means ? Or is it just some junk value ? My understanding was the SWITCH_INFPREV traces the domain to be descheduled and SWITCH_INFNEXT traces to be scheduled. If thats the case, then why is current DOM ID a junk value. Any pointer to the the source code to understand this better will be helpful. If I look at xm list it shows - [root@samoa3 mahendra 04:13 PM]$ xm list Name ID Mem VCPUs State Time(s) Domain-0 0 1022 8 r----- 94726.9 mapache 24 256 1 -b---- 739.7 mmysql 22 256 1 -b---- 99.1 mtomcat 23 256 1 -b---- 522.4 So for Domain-0 with DOM ID of 0 makes sense but what about the OLD DOM ID value. If I look at another trace record - CPU0 7997860846373115 (+ 2130) domain_wake [ domid 0x00000018, edomid = 0x00000000 ] Here, it make sense that domid is 24 which is mpache domain as listed by xm list. Can anyone help me understand this and point to relevant source code ? Thanks Mahendra On Tue, Jul 6, 2010 at 3:12 PM, Mahendra Kutare <mahendra.kutare@gmail.com> wrote:> Hi All, > > I am working on a research project and as part of my investigation I am > trying to figure out is there a way or even possible to get the process tree > of each VM from either dom0 or hypervisor level ? > > Even if its slightly inaccurate view or buried deep in some data structure I > would like to know if even its possible or not ? > > Any pointers for the same will be highly appreciated. > > Thanks > Mahendra >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Mahendra Kutare
2010-Jul-26 13:24 UTC
[Xen-devel] How to read the xen format file and the generated trace content ?
Hi All, I am trying to understand the format file which comes with too/xentrace/formats. If anyone can help in understanding the following, that will be great - Take for example - 0x0002800e CPU%(cpu)d %(tsc)d (+%(reltsc)8d) switch_infprev [ old_domid = 0x%(1)08x, runtime = %(2)d ] 0x0002800f CPU%(cpu)d %(tsc)d (+%(reltsc)8d) switch_infnext [ new_domid = 0x%(1)08x, time = %(2)d, r_time = %(3)d ] In the above format rule, 1. Can anyone point me to the source code that populates the cpu and tsc using xentrace data ? 2. In the above, I understand 1, 2 and 3 means first, second and third field from the TRACE but what does the whole field description means i.e. 0x%(1)08x apart from the fact that it represents hexadecimal value for DOM IDs. If above represents DOM ID values then from the trace data generated like this - CPU0 7997860846654673 (+ 4133) switch_infprev [ old_domid 0x00007fff, runtime = 79935 ] CPU0 7997860846655190 (+ 517) switch_infnext [ new_domid 0x00000000, time = 3889, r_time = 30000000 ] old_domid = 0x00007fff represents 32767 for some some DOM ID. There is no domain which has been assigned the 32767 id or for that matter DOM0. new_domid = 0x00000000 represents 0 which is clearly the DOM0 id. So what is this old_domid value means ? Or is it just some junk value ? My understanding was the SWITCH_INFPREV traces the domain to be descheduled and SWITCH_INFNEXT traces to be scheduled. If thats the case, then why is current DOM ID a junk value. Any pointer to the the source code to understand this better will be helpful. If I look at xm list it shows - [root@samoa3 mahendra 04:13 PM]$ xm list Name ID Mem VCPUs State Time(s) Domain-0 0 1022 8 r----- 94726.9 mapache 24 256 1 -b---- 739.7 mmysql 22 256 1 -b---- 99.1 mtomcat 23 256 1 -b---- 522.4 So for Domain-0 with DOM ID of 0 makes sense but what about the OLD DOM ID value. If I look at another trace record - CPU0 7997860846373115 (+ 2130) domain_wake [ domid 0x00000018, edomid = 0x00000000 ] Here, it make sense that domid is 24 which is mpache domain as listed by xm list. Can anyone help me understand this and point to relevant source code ? Thanks Mahendra _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel