LOCKSTAT(8)             NetBSD System Manager's Manual             LOCKSTAT(8)


NAME
lockstat -- display kernel locking statistics
SYNOPSIS
lockstat [-cdeflMmpstx] [-b nbuf] [-E event] [-F func] [-L lock] [-N nlist] [-o file] [-T type] command ...
DESCRIPTION
The lockstat command enables system wide tracing of kernel lock events, executes the specified command, and when finished reports statistics to the user. Tracing may be ended early by sending SIGINT (Ctrl-C) to the process being executed by lockstat. The lockstat pseudo-device driver must be present in the kernel, and the lockstat command may only be used by the root user. The options are as follows: -b nbuf Adjust the number of trace buffers allocated by the kernel to nbuf. -c Report percentage of total events by count, and sort the out- put by number of events. The default is to key on event tim- ings. -d Disable lockstat. This is useful when a program crashed leav- ing the lockstat kernel driver enabled. -E event Limit tracing to one type of event. Use the -e option to list valid events. -e List valid event types for the -E option and exit. -F func Limit tracing to locking operations performed within the spec- ified function. func must be the name of a valid function in the kernel. -f Trace only by calling functions; do not report on individual locks. -L lock Limit tracing to one lock. lock may either be the name of a lock object in the kernel, or a kernel virtual address. -l Trace only by lock; do not report on calling functions. -M Merge lock addresses within unique objects. -m Merge call sites within unique functions. -N nlist Extract symbol information from the nlist file. -o file Send output to the file named by file, instead of the standard output (the default). -p Show the average number of events and time spent per CPU. The default is to show the total values. May be used in conjunc- tion with the -s option. -s Show the average number of events per second, and the average time spent per second. The default is to show the total val- ues. -T type Limit tracing to one type of lock. Use the -t option to list valid lock types. -t List valid lock types for the -T option and exit. -x Summarize events, and do not report on lock types.
FILES
/dev/lockstat lockstat control device /dev/ksyms namelist
EXAMPLES
# lockstat -L uvm_pageqlock sleep 10 Elapsed time: 10.01 seconds. -- Adaptive mutex spin Total% Count Time/ms Lock Caller ------ ------- --------- ---------------------- ------------------------------ 100.00 1281 0.78 uvm_pageqlock <all> 39.81 385 0.31 uvm_pageqlock uvm_fault_internal+11cc 30.98 358 0.24 uvm_pageqlock uvm_fault_internal+bb1 28.06 522 0.22 uvm_pageqlock uvm_anfree+132 0.51 5 0.00 uvm_pageqlock ubc_fault+28f 0.20 4 0.00 uvm_pageqlock uvm_fault_internal+12b6 0.18 2 0.00 uvm_pageqlock uao_detach_locked+58 0.11 2 0.00 uvm_pageqlock uvm_fault_internal+7d5 0.08 2 0.00 uvm_pageqlock ufs_balloc_range+160 0.07 1 0.00 uvm_pageqlock uvm_fault_internal+107b
DIAGNOSTICS
lockstat: incompatible lockstat interface version The kernel device driver does not match the version of the lockstat com- mand. lockstat: overflowed available kernel trace buffers Increase the number of buffers using the -b option. lockstat: ioctl: Invalid argument The number of trace buffers is outside the minimum and maximum bounds set by the kernel.
SEE ALSO
ps(1), systat(1), vmstat(1), iostat(8), pstat(8)
HISTORY
The lockstat command appeared in NetBSD 4.0. NetBSD 9.0 March 6, 2013 NetBSD 9.0

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