FreeBSD src
Go to file
Mitchell Horne da5b7e90e7 boottrace: a simple boot and shutdown-time tracing facility
Boottrace is a facility for capturing trace events during boot and
shutdown. This includes kernel initialization, as well as rc. It has
been used by NetApp internally for several years, for catching and
diagnosing slow devices or subsystems. It is driven from userspace by
sysctl interface, and the output is a human-readable log of events
(kern.boottrace.log).

This commit adds the core boottrace functionality implementing these
interfaces. Adding the trace annotations themselves to kernel and
userland will happen in follow-up commits. A future commit will also add
a boottrace(4) man page.

For now, boottrace is unconditionally compiled into the kernel but
disabled by default. It can be enabled by setting the
kern.boottrace.enabled tunable to 1 in loader.conf(5).

There is an existing boot-time event tracing facility, which can be
compiled into the kernel with 'options TSLOG'. While there is some
functional overlap between this and boottrace, they are distinct. TSLOG
is suitable for generating detailed timing information and flamegraphs,
and has been used to great success by cperciva@ to diagnose and reduce
the overall system boot time. Boottrace aims to more quickly provide an
overview of timing and resource usage of the boot (and shutdown) process
to a sysadmin who requires this knowledge.

Sponsored by:	NetApp, Inc.
Sponsored by:	Klara, Inc.
X-NetApp-PR:	#23
Differential Revision:	https://reviews.freebsd.org/D30184
2022-02-21 20:15:45 -04:00
.cirrus-ci
.github Update vendor/libarchive to libarchive/libarchive@72ce1ff7c 2022-02-19 00:49:06 +01:00
bin bin/df: allow -t option to be used together with -l 2022-02-10 21:09:34 +01:00
cddl ctfconvert: Rip out STABS support 2022-02-10 15:41:10 -05:00
contrib libarchive: merge vendor bugfix 2022-02-21 12:06:54 +01:00
crypto OpenSSL: Fix the same BIO_FLAGS macro definition 2022-02-01 10:38:49 -08:00
etc Integrate contrib/file/tests with kyua/atf 2022-02-16 13:02:45 -06:00
gnu libdialog: Bump shared library version to 10. 2021-10-27 09:30:24 -07:00
include Install unwind.h into /usr/include 2022-02-10 19:00:32 +01:00
kerberos5 pkgbase: Create a FreeBSD-kerberos package 2021-09-07 10:23:14 +02:00
lib libpmc: Allow specifying explicit EVENT_xxH events on armv7 and arm64 2022-02-15 16:10:34 +00:00
libexec gssd: Modify /etc/rc.d/gssd so that it starts after NETWORKING 2022-02-15 14:18:23 -08:00
release release: Don't install ubldr.bin 2022-02-07 13:19:20 -07:00
rescue rescue: Link with -lncursesw instead of -lncursesw_real. 2022-02-11 13:58:59 -08:00
sbin nvme: fix spelling of Namespace 2022-02-21 10:34:46 -08:00
secure OpenSSL: Merge OpenSSL 1.1.1m 2021-12-14 16:03:52 -05:00
share man: Remove mention of EXT_RESOURCES 2022-02-21 17:29:17 +01:00
stand Add support for getting early entropy from UEFI 2022-02-17 13:01:11 -08:00
sys boottrace: a simple boot and shutdown-time tracing facility 2022-02-21 20:15:45 -04:00
targets Retire obsolete iscsi_initiator(4) 2021-10-26 16:17:35 -04:00
tests mmap map_at_zero test: handle W^X 2022-02-21 09:43:42 -06:00
tools Clean up warnings in pthread tests 2022-02-16 16:28:31 -05:00
usr.bin Temporarily skip usr.bin.diff.diff_test.functionname in CI 2022-02-21 16:31:43 +08:00
usr.sbin nvme: fix spelling of Namespace 2022-02-21 10:34:46 -08:00
.arcconfig
.arclint
.cirrus.yml Cirrus-CI: add a manual amd64-gcc9 build and smoketest job 2022-02-15 12:55:14 -05:00
.clang-format clang-format: Add bitset loop macros 2021-09-21 12:08:01 -04:00
.gitattributes
.gitignore Update vendor/libarchive libarchive/libarchive@9147def1d 2022-02-09 14:20:23 +01:00
COPYRIGHT Welcome 2022, update copyrights. 2022-01-01 09:49:49 -07:00
LOCKS
MAINTAINERS Remove myself from bhyve maintenance; ENOTIME. 2021-11-19 07:09:30 +10:00
Makefile cleankernel: A target to delete the kernel compile file 2022-02-11 12:51:24 -07:00
Makefile.inc1 cleankernel: A target to delete the kernel compile file 2022-02-11 12:51:24 -07:00
Makefile.libcompat Makefile.libcompat: Sort 2022-02-02 14:34:29 -07:00
Makefile.sys.inc
ObsoleteFiles.inc Install unwind.h into /usr/include 2022-02-10 19:00:32 +01:00
README.md unbound: Vendor import 1.15.0 2022-02-17 14:47:14 -08:00
RELNOTES RELNOTES: Note support for KTLS RX for TLS 1.3. 2021-12-14 11:02:45 -08:00
UPDATING Fix minor grammar nit. 2022-01-31 15:35:23 -08:00

FreeBSD Source:

This is the top level of the FreeBSD source directory.

FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.

For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.

The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.

Source Roadmap:

Directory Description
bin System/user commands.
cddl Various commands and libraries under the Common Development and Distribution License.
contrib Packages contributed by 3rd parties.
crypto Cryptography stuff (see crypto/README).
etc Template files for /etc.
gnu Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information.
include System include files.
kerberos5 Kerberos5 (Heimdal) package.
lib System libraries.
libexec System daemons.
release Release building Makefile & associated tools.
rescue Build system for statically linked /rescue utilities.
sbin System commands.
secure Cryptographic libraries and commands.
share Shared resources.
stand Boot loader sources.
sys Kernel sources.
sys/arch/conf Kernel configuration files. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries.
tests Regression tests which can be run by Kyua. See tests/README for additional information.
tools Utilities for regression testing and miscellaneous tasks.
usr.bin User commands.
usr.sbin System administration commands.

For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.