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
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config.mk
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files	boottrace: a simple boot and shutdown-time tracing facility	2022-02-21 20:15:45 -04:00
files.amd64
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files.arm64	files: Make ext_resources non-optional	2022-02-21 17:29:06 +01:00
files.i386
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files.riscv	files: Make ext_resources non-optional	2022-02-21 17:29:06 +01:00
files.x86
kern.mk
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kmod_syms_prefix.awk
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kmod.mk
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ldscript.amd64
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Makefile.amd64
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newvers.sh
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options	options: Remove EXT_RESOURCES	2022-02-21 17:29:15 +01:00
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