Section 9.5. DTrace Kernel Profiling

9.5. DTrace Kernel Profiling

The profile provider in DTrace identifies hot functions by sampling the kernel stack activity.

# dtrace -n 'profile-997hz / arg0 != 0 / { @ks[stack()]=count() }' dtrace: description 'profile-997ms ' matched 1 probe ^C               genunix'syscall_mstate+0x1c7               unix'sys_syscall32+0xbd                 1               unix'bzero+0x3               procfs'pr_read_lwpusage_32+0x2f               procfs'prread+0x5d               genunix'fop_read+0x29               genunix'pread+0x217               genunix'pread32+0x26               unix'sys_syscall32+0x101                 1               unix'kcopy+0x38               genunix'copyin_nowatch+0x48               genunix'copyin_args32+0x45               genunix'syscall_entry+0xcb               unix'sys_syscall32+0xe1                 1               unix'sys_syscall32+0xae                 1               unix'mutex_exit+0x19               ufs'rdip+0x368               ufs'ufs_read+0x1a6               genunix'fop_read+0x29               genunix'pread64+0x1d7               unix'sys_syscall32+0x101                 2               unix'kcopy+0x2c               genunix'uiomove+0x17f               ufs'rdip+0x382               ufs'ufs_read+0x1a6               genunix'fop_read+0x29               genunix'pread64+0x1d7               unix'sys_syscall32+0x101                13