From: Philippe Proulx Date: Tue, 6 Dec 2016 15:09:18 +0000 (-0500) Subject: 2.8, 2.9: getting-started: fix and update procedures X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=cdd6b15373374828b7de42755b1c1e761b05ba2f;p=lttng-docs.git 2.8, 2.9: getting-started: fix and update procedures Signed-off-by: Philippe Proulx --- diff --git a/2.8/lttng-docs-2.8.txt b/2.8/lttng-docs-2.8.txt index 5a42c47..fb3d2f6 100644 --- a/2.8/lttng-docs-2.8.txt +++ b/2.8/lttng-docs-2.8.txt @@ -864,12 +864,13 @@ The following command lines start with cmd:sudo because you need root privileges to trace the Linux kernel. You can avoid using cmd:sudo if your Unix user is a member of the <>. -. Create a <>: +. Create a <> which writes its traces + to dir:{/tmp/my-kernel-trace}: + -- [role="term"] ---- -sudo lttng create my-kernel-session +sudo lttng create my-kernel-session --output=/tmp/my-kernel-trace ---- -- @@ -879,20 +880,23 @@ sudo lttng create my-kernel-session [role="term"] ---- lttng list --kernel +lttng list --kernel --syscall ---- -- -. Create an <> which matches the desired event names, - for example `sched_switch` and `sched_process_fork`: +. Create <> which match the desired instrumentation + point names, for example the `sched_switch` and `sched_process_fork` + tracepoints, and the man:open(2) and man:close(2) system calls: + -- [role="term"] ---- sudo lttng enable-event --kernel sched_switch,sched_process_fork +sudo lttng enable-event --kernel --syscall open,close ---- -- + -You can also create an event rule which _matches_ all the Linux kernel +You can also create an event rule which matches _all_ the Linux kernel tracepoints (this will generate a lot of data when tracing): + -- @@ -902,7 +906,7 @@ sudo lttng enable-event --kernel --all ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -913,7 +917,8 @@ sudo lttng start . Do some operation on your system for a few seconds. For example, load a website, or list the files of a directory. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -926,10 +931,15 @@ sudo lttng destroy The man:lttng-destroy(1) command does not destroy the trace data; it only destroys the state of the tracing session. -By default, LTTng saves the traces in -+$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the -env:LTTNG_HOME environment variable defaults to `$HOME` if not set. +. For the sake of this example, make the recorded trace accessible to + the non-root users: ++ +-- +[role="term"] +---- +sudo chown -R $(whoami) /tmp/my-kernel-trace +---- +-- See <> to view the recorded events. @@ -1141,7 +1151,7 @@ lttng enable-event --userspace hello_world:my_first_tracepoint ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -1152,7 +1162,8 @@ lttng start . Go back to the running `hello` application and press Enter. The program executes all `tracepoint()` instrumentation points and exits. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -1167,7 +1178,7 @@ only destroys the state of the tracing session. By default, LTTng saves the traces in +$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the +where +__name__+ is the tracing session name. The env:LTTNG_HOME environment variable defaults to `$HOME` if not set. See <>. -. Create a <>: +. Create a <> which writes its traces + to dir:{/tmp/my-kernel-trace}: + -- [role="term"] ---- -sudo lttng create my-kernel-session +sudo lttng create my-kernel-session --output=/tmp/my-kernel-trace ---- -- @@ -632,20 +633,23 @@ sudo lttng create my-kernel-session [role="term"] ---- lttng list --kernel +lttng list --kernel --syscall ---- -- -. Create an <> which matches the desired event names, - for example `sched_switch` and `sched_process_fork`: +. Create <> which match the desired instrumentation + point names, for example the `sched_switch` and `sched_process_fork` + tracepoints, and the man:open(2) and man:close(2) system calls: + -- [role="term"] ---- sudo lttng enable-event --kernel sched_switch,sched_process_fork +sudo lttng enable-event --kernel --syscall open,close ---- -- + -You can also create an event rule which _matches_ all the Linux kernel +You can also create an event rule which matches _all_ the Linux kernel tracepoints (this will generate a lot of data when tracing): + -- @@ -655,7 +659,7 @@ sudo lttng enable-event --kernel --all ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -666,7 +670,8 @@ sudo lttng start . Do some operation on your system for a few seconds. For example, load a website, or list the files of a directory. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -679,10 +684,15 @@ sudo lttng destroy The man:lttng-destroy(1) command does not destroy the trace data; it only destroys the state of the tracing session. -By default, LTTng saves the traces in -+$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the -env:LTTNG_HOME environment variable defaults to `$HOME` if not set. +. For the sake of this example, make the recorded trace accessible to + the non-root users: ++ +-- +[role="term"] +---- +sudo chown -R $(whoami) /tmp/my-kernel-trace +---- +-- See <> to view the recorded events. @@ -894,7 +904,7 @@ lttng enable-event --userspace hello_world:my_first_tracepoint ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -905,7 +915,8 @@ lttng start . Go back to the running `hello` application and press Enter. The program executes all `tracepoint()` instrumentation points and exits. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -920,7 +931,7 @@ only destroys the state of the tracing session. By default, LTTng saves the traces in +$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the +where +__name__+ is the tracing session name. The env:LTTNG_HOME environment variable defaults to `$HOME` if not set. See <