FreeBSD Manual Pages
DT(4) FreeBSD Kernel Interfaces Manual DT(4) NAME dt -- dynamic tracer SYNOPSIS pseudo-device dt DESCRIPTION System and application tracing can happen in the kernel. It has to be configured and enabled through the ioctl(2) interface exposed by the pseudo-device /dev/dt. This device can only be opened when the kern.allowdt sysctl(2) variable is set. IOCTL INTERFACE The ioctl(2) command codes below are defined in <dev/dt/dtvar.h>. DTIOCGPLIST struct dtioc_probe *dtpr Get available probe entries. struct dtioc_probe { size_t dtpr_size; struct dtioc_probe_info *dtpr_probes; }; If dtpr_size is non-zero, as many probes as possible that can fit into this size will be copied into the supplied buffer. On exit, dtpr_size is always set to the total size required to hold all probe entries (i.e., it is set to sizeof(struct dtioc_probe_info) * dt_nprobes). DTIOCGSTATS struct dtioc_stat *dtst Get statistics for current recording. struct dtioc_stat { uint64_t dtst_readevt; uint64_t dtst_dropevt; }; DTIOCRECORD int on Start or stop recording. DTIOCPRBENABLE struct dtioc_req *dtrq Enable the given probe for recording. struct dtioc_req { uint32_t dtrq_pbn; struct dt_filter dtrq_filter; uint32_t dtrq_rate; uint64_t dtrq_evtflags; }; FILES /dev/dt dynamic tracing device. ERRORS An open of /dev/dt will fail if: [EPERM] the kern.allowdt sysctl(2) variable wasn't set. [ENOMEM] not enough memory space was available. SEE ALSO ioctl(2), bt(5), btrace(8) HISTORY The dt dynamic tracing mechanism first appeared in OpenBSD 6.7. FreeBSD 13.0 December 2, 2020 FreeBSD 13.0
NAME | SYNOPSIS | DESCRIPTION | IOCTL INTERFACE | FILES | ERRORS | SEE ALSO | HISTORY
Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=dt&sektion=4&manpath=OpenBSD+6.9>