xentrace(8) [suse man page]
XENTRACE(8) System Manager's Manual XENTRACE(8) NAME
xentrace - capture Xen trace buffer data SYNOPSIS
xentrace [ OPTIONS ] [ FILE ] DESCRIPTION
xentrace is used to capture trace buffer data from Xen. The data is output in the following binary format (host endian): CPU(uint) TSC(u64) EVENT(u32) D1 D2 D3 D4 D5 (all u32) Where CPU is the processor number, TSC is the record's timestamp (the value of the CPU cycle counter), EVENT is the event ID and D1...D5 are the trace data. Data is dumped onto the standard output (which must not be a TTY) or a FILE specified on the command line. The output should be parsed using the tool xentrace_format, which can produce human-readable output in ASCII format. Options -t, --log-thresh=l set the threshold number, l, of new records required to trigger a write of all new records to the output -s, --poll-sleep=p set the time, p, (in milliseconds) to sleep between polling the buffers for new data. -c, --cpu-mask=c set cpu-mask -e, --evt-mask=e set evt-mask -?, --help Give this help list --usage Give a short usage message -V, --version Print program version Event Classes (Masks) The following event classes (masks) can be used to filter the events being gathered by xentrace: ID Description 0x0001f000 TRC_GEN 0x0002f000 TRC_SCHED 0x0004f000 TRC_DOM0OP 0x0008f000 TRC_HVM 0x0010f000 TRC_MEM 0xfffff000 TRC_ALL Event Subclasses (More Masks) The following event subclasses (masks) can also be used to filter the events being gathered by xentrace: ID Description 0x00081000 TRC_HVM_ENTRYEXIT 0x00082000 TRC_HVM_HANDLER Events xentrace collects the following events from the trace buffer: ID Description 0x0001f001 TRC_LOST_RECORDS 0x0002f001 TRC_SCHED_DOM_ADD 0x0002f002 TRC_SCHED_DOM_REM 0x0002f003 TRC_SCHED_SLEEP 0x0002f004 TRC_SCHED_WAKE 0x0002f005 TRC_SCHED_YIELD 0x0002f006 TRC_SCHED_BLOCK 0x0002f007 TRC_SCHED_SHUTDOWN 0x0002f008 TRC_SCHED_CTL 0x0002f009 TRC_SCHED_ADJDOM 0x0002f010 TRC_SCHED_SWITCH 0x0002f011 TRC_SCHED_S_TIMER_FN 0x0002f012 TRC_SCHED_T_TIMER_FN 0x0002f013 TRC_SCHED_DOM_TIMER_FN 0x0002f014 TRC_SCHED_SWITCH_INFPREV 0x0002f015 TRC_SCHED_SWITCH_INFNEXT 0x00081001 TRC_HVM_VMENTRY 0x00081002 TRC_HVM_VMEXIT 0x00082001 TRC_HVM_PF_XEN 0x00082002 TRC_HVM_PF_INJECT 0x00082003 TRC_HVM_INJ_EXC 0x00082004 TRC_HVM_INJ_VIRQ 0x00082005 TRC_HVM_REINJ_VIRQ 0x00082006 TRC_HVM_IO_READ 0x00082007 TRC_HVM_IO_WRITE 0x00082008 TRC_HVM_CR_READ 0x00082009 TRC_HVM_CR_WRITE 0x0008200A TRC_HVM_DR_READ 0x0008200B TRC_HVM_DR_WRITE 0x0008200C TRC_HVM_MSR_READ 0x0008200D TRC_HVM_MSR_WRITE 0x0008200E TRC_HVM_CPUID 0x0008200F TRC_HVM_INTR 0x00082010 TRC_HVM_NMI 0x00082011 TRC_HVM_SMI 0x00082012 TRC_HVM_VMMCALL 0x00082013 TRC_HVM_HLT 0x00082014 TRC_HVM_INVLPG 0x0010f001 TRC_MEM_PAGE_GRANT_MAP 0x0010f002 TRC_MEM_PAGE_GRANT_UNMAP 0x0010f003 TRC_MEM_PAGE_GRANT_TRANSFER AUTHOR
Mark A. Williamson <mark.a.williamson@intel.com> SEE ALSO
xentrace_format(1) Xen domain 0 utils 22 February 2007 XENTRACE(8)
Check Out this Related Man Page
KTR(4) BSD Kernel Interfaces Manual KTR(4) NAME
ktr -- kernel tracing facility SYNOPSIS
options KTR options ALQ options KTR_ALQ options KTR_COMPILE=(KTR_LOCK|KTR_INTR|KTR_PROC) options KTR_CPUMASK=0x3 options KTR_ENTRIES=8192 options KTR_MASK=(KTR_INTR|KTR_PROC) options KTR_VERBOSE DESCRIPTION
The ktr facility allows kernel events to be logged while the kernel executes so that they can be examined later when debugging. The only mandatory option to enable ktr is ``options KTR''. The KTR_ENTRIES option sets the size of the buffer of events. It must be a power of two. The size of the buffer in the currently running kernel can be found via the read-only sysctl debug.ktr.entries. By default the buffer contains 1024 entries. Event Masking Event levels can be enabled or disabled to trim excessive and overly verbose logging. First, a mask of events is specified at compile time via the KTR_COMPILE option to limit which events are actually compiled into the kernel. The default value for this option is for all events to be enabled. Secondly, the actual events logged while the kernel runs can be further masked via the run time event mask. The KTR_MASK option sets the default value of the run time event mask. The runtime event mask can also be set by the loader(8) via the debug.ktr.mask environment vari- able. It can also be examined and set after booting via the debug.ktr.mask sysctl. By default the run time mask is set to log only KTR_GEN events. The definitions of the event mask bits can be found in <sys/ktr.h>. Furthermore, there is a CPU event mask whose default value can be changed via the KTR_CPUMASK option. A CPU must have the bit corresponding to its logical id set in this bitmask for events that occur on it to be logged. This mask can be set by the loader(8) via the debug.ktr.cpumask environment variable. It can also be examined and set after booting via the debug.ktr.cpumask sysctl. By default events on all CPUs are enabled. Verbose Mode By default, events are only logged to the internal buffer for examination later, but if the verbose flag is set then they are dumped to the kernel console as well. This flag can also be set from the loader via the debug.ktr.verbose environment variable, or it can be examined and set after booting via the debug.ktr.verbose sysctl. If the flag is set to zero, which is the default, then verbose output is disabled. If the flag is set to one, then the contents of the log message and the CPU number are printed to the kernel console. If the flag is greater than one, then the filename and line number of the event are output to the console in addition to the log message and the CPU number. The KTR_VERBOSE option sets the flag to one. Examining the Events The KTR buffer can be examined from within ddb(4) via the show ktr [/v] command. This command displays the contents of the trace buffer one page at a time. At the ``--more--'' prompt, the Enter key displays one more entry and prompts again. The spacebar displays another page of entries. Any other key quits. By default the timestamp, filename, and line number are not displayed with each log entry. If the /v modi- fier is specified, then they are displayed in addition to the normal output. Note that the events are displayed in reverse chronological order. That is, the most recent events are displayed first. Logging ktr to Disk The KTR_ALQ option can be used to log ktr entries to disk for post analysis using the ktrdump(8) utility. This option depends on the ALQ option. Due to the potentially high volume of trace messages the trace mask should be selected carefully. This feature is configured through a group of sysctls. debug.ktr.alq_file displays or sets the file that ktr will log to. By default its value is /tmp/ktr.out. If the file name is changed while ktr is enabled it will not take effect until the next invocation. debug.ktr.alq_enable enables logging of ktr entries to disk if it is set to one. Setting this to 0 will terminate logging. debug.ktr.alq_max is the maximum number of entries that will be recorded to disk, or 0 for infinite. This is helpful for limiting the number of particularly high frequency entries that are recorded. debug.ktr.alq_depth determines the number of entries in the write buffer. This is the buffer that holds entries before they are written to disk and defaults to the value of the KTR_ENTRIES option. debug.ktr.alq_failed records the number of times we failed to write an entry due to overflowing the write buffer. This may happen if the frequency of the logged ktr messages outpaces the depth of the queue. debug.ktr.alq_cnt records the number of entries that have currently been written to disk. SEE ALSO
ktrdump(8), alq(9), ktr(9) HISTORY
The KTR kernel tracing facility first appeared in BSD/OS 3.0 and was imported into FreeBSD 5.0. BSD
January 25, 2005 BSD