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tnf_kernel_probes(4) [opensolaris man page]

tnf_kernel_probes(4)						   File Formats 					      tnf_kernel_probes(4)

NAME
tnf_kernel_probes - TNF kernel probes DESCRIPTION
The set of probes (trace instrumentation points) available in the standard kernel. The probes log trace data to a kernel trace buffer in Trace Normal Form (TNF). Kernel probes are controlled by prex(1). A snapshot of the kernel trace buffer can be made using tnfxtract(1) and examined using tnfdump(1). Each probe has a name and is associated with a set of symbolic keys, or categories. These are used to select and control probes from prex(1). A probe that is enabled for tracing generates a TNF record, called an event record. An event record contains two common members and may contain other probe-specific data members. Common Members tnf_probe_event tag tnf_time_delta time_delta tag Encodes TNF references to two other records: tag Describes the layout of the event record. schedule Identifies the writing thread and also contains a 64-bit base time in nanoseconds. time_delta A 32-bit time offset from the base time; the sum of the two times is the actual time of the event. Threads thread_create tnf_kthread_id tid tnf_pid pid tnf_symbol start_pc Thread creation event. tid The thread identifier for the new thread. pid The process identifier for the new thread. start_pc The kernel address of its start routine. thread_state tnf_kthread_id tid tnf_microstate state Thread microstate transition events. tid Optional; if it is absent, the event is for the writing thread, otherwise the event is for the specified thread. state Indicates the thread state: o Running in user mode. o Running in system mode. o Asleep waiting for a user-mode lock. o Asleep on a kernel object. o Runnable (waiting for a cpu). o Stopped. The values of this member are defined in <sys/msacct.h>. Note that to reduce trace output, transitions between the system and user microstates that are induced by system calls are not traced. This information is implicit in the system call entry and exit events. thread_exit Thread termination event for writing thread. This probe has no data members other than the common members. Scheduling thread_queue tnf_kthread_id tid tnf_cpuid cpuid tnf_long priority tnf_ulong queue_length Thread scheduling events. These are triggered when a runnable thread is placed on a dispatch queue. cpuid Specifies the cpu to which the queue is attached. priority The (global) dispatch priority of the thread. queue_length The current length of the cpu's dispatch queue. Blocking thread_block tnf_opaque reason tnf_symbols stack Thread blockage event. This probe captures a partial stack backtrace when the current thread blocks. reason The address of the object on which the thread is blocking. symbols References a TNF array of kernel addresses representing the PCs on the stack at the time the thread blocks. System Calls syscall_start tnf_sysnum sysnum System call entry event. sysnum The system call number. The writing thread implicitly enters the system microstate with this event. syscall_end tnf_long rval1 tnf_long rval2 tnf_long errno System call exit event. rval1 and rval2 The two return values of the system call errno The error return. The writing thread implicitly enters the user microstate with this event. Page Faults address_fault tnf_opaque address tnf_fault_type fault_type tnf_seg_access access Address-space fault event. address Gives the faulting virtual address. fault_type Gives the fault type: invalid page, protection fault, software requested locking or unlocking. access Gives the desired access protection: read, write, execute or create. The values for these two members are defined in <vm/seg_enum.h>. major_fault tnf_opaque vnode tnf_offset offset Major page fault event. The faulting page is mapped to the file given by the vnode member, at the given offset into the file. (The fault- ing virtual address is in the most recent address_fault event for the writing thread.) anon_private tnf_opaque address Copy-on-write page fault event. address The virtual address at which the new page is mapped. anon_zero tnf_opaque address Zero-fill page fault event. address The virtual address at which the new page is mapped. page_unmap tnf_opaque vnode tnf_offset offset Page unmapping event. This probe marks the unmapping of a file system page from the system. vnode and offset Identifies the file and offset of the page being unmapped. Pageins and Pageouts pagein tnf_opaque vnode tnf_offset offset tnf_size size Pagein start event. This event signals the initiation of pagein I/O. vnodeandoffset Identifyies the file and offset to be paged in. size Specifies the number of bytes to be paged in. pageout tnf_opaque vnode tnf_ulong pages_pageout tnf_ulong pages_freed tnf_ulong pages_reclaimed Pageout completion event. This event signals the completion of pageout I/O. vnode Identifies the file of the pageout request. pages_pageout The number of pages written out. pages_freed The number of pages freed after being written out. pages_reclaimed The number of pages reclaimed after being written out. Page Daemon (Page Stealer) pageout_scan_start tnf_ulong pages_free tnf_ulong pages_needed Page daemon scan start event. This event signals the beginning of one iteration of the page daemon. pages_free The number of free pages in the system. pages_needed The number of pages desired free. pageout_scan_end tnf_ulong pages_free tnf_ulong pages_scanned Page daemon scan end event. This event signals the end of one iteration of the page daemon. pages_free The number of free pages in the system. pages_scanned The number of pages examined by the page daemon. (Potentially more pages will be freed when any queued pageout requests complete.) Swapper swapout_process tnf_pid pid tnf_ulong page_count Address space swapout event. This event marks the swapping out of a process address space. pid Identifies the process. page_count Reports the number of pages either freed or queued for pageout. swapout_lwp tnf_pid pid tnf_lwpid lwpid tnf_kthread_id tid tnf_ulong page_count Light-weight process swapout event. This event marks the swapping out of an LWP and its stack. pid The LWP's process identifier lwpid The LWP identifier tid member The LWP's kernel thread identifier. page_count The number of pages swapped out. swapin_lwp tnf_pid pid tnf_lwpid lwpid tnf_kthread_id tid tnf_ulong page_count Light-weight process swapin event. This event marks the swapping in of an LWP and its stack. pid The LWP's process identifier. lwpid The LWP identifier. tid The LWP's kernel thread identifier. page_count The number of pages swapped in. Local I/O strategy tnf_device device tnf_diskaddr block tnf_size size tnf_opaque buf tnf_bioflags flags Block I/O strategy event. This event marks a call to the strategy(9E) function of a block device driver. device Contains the major and minor numbers of the device. block The logical block number to be accessed on the device. size The size of the I/O request. buf The kernel address of the buf(9S) structure associated with the transfer. flags The buf(9S) flags associated with the transfer. biodone tnf_device device tnf_diskaddr block tnf_opaque buf Buffered I/O completion event. This event marks calls to the biodone(9F) function. device Contains the major and minor numbers of the device. block The logical block number accessed on the device. buf The kernel address of the buf(9S) structure associated with the transfer. physio_start tnf_device device tnf_offset offset tnf_size size tnf_bioflags rw Raw I/O start event. This event marks entry into the physio(9F) fufnction which performs unbuffered I/O. device Contains the major and minor numbers of the device of the transfer. offset The logical offset on the device for the transfer. size The number of bytes to be transferred. rw The direction of the transfer: read or write (see buf(9S)). physio_end tnf_device device Raw I/O end event. This event marks exit from the physio(9F) fufnction. device The major and minor numbers of the device of the transfer. USAGE
Use the prex utility to control kernel probes. The standard prex commands to list and manipulate probes are available to you, along with commands to set up and manage kernel tracing. Kernel probes write trace records into a kernel trace buffer. You must copy the buffer into a TNF file for post-processing; use the tnfx- tract utility for this. You use the tnfdump utility to examine a kernel trace file. This is exactly the same as examining a user-level trace file. The steps you typically follow to take a kernel trace are: 1. Become superuser (su). 2. Allocate a kernel trace buffer of the desired size (prex). 3. Select the probes you want to trace and enable (prex). 4. Turn kernel tracing on (prex). 5. Run your application. 6. Turn kernel tracing off (prex). 7. Extract the kernel trace buffer (tnfxtract). 8. Disable all probes (prex). 9. Deallocate the kernel trace buffer (prex). 10. Examine the trace file (tnfdump). A convenient way to follow these steps is to use two shell windows; run an interactive prex session in one, and run your application and tnfxtract in the other. SEE ALSO
prex(1), tnfdump(1), tnfxtract(1), libtnfctl(3TNF), TNF_PROBE(3TNF), tracing(3TNF), strategy(9E), biodone(9F), physio(9F), buf(9S) SunOS 5.11 8 Nov1999 tnf_kernel_probes(4)

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