X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng.1;h=283367190a30e010805db1cb3d8d971931ff794c;hb=bd337b98fea4ce3f2073bf83394a3e6e3dd9cf71;hp=37c206398deeb1771813ca7592d8cafff7f27863;hpb=1cb514cec8d71a17376a1f2e78f0a68f2f410521;p=lttng-tools.git diff --git a/doc/man/lttng.1 b/doc/man/lttng.1 index 37c206398..283367190 100644 --- a/doc/man/lttng.1 +++ b/doc/man/lttng.1 @@ -1,7 +1,7 @@ .TH "LTTNG" "1" "December 3rd, 2012" "" "" .SH "NAME" -lttng \(em LTTng 2.1.x tracer control command line tool +lttng \(em LTTng 2.x tracer control command line tool .SH "SYNOPSIS" @@ -101,8 +101,9 @@ data output: Please take a look at the help (\-h/\-\-help) for a detailed list of available contexts. -If no channel is given (\-c), the context is added to all channels. Otherwise -the context will be added only to the given channel (\-c). +If no channel is given (\-c), the context is added to all channels that were +already enabled. If the session has no channel, a default channel is created. +Otherwise the context will be added only to the given channel (\-c). If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc file. @@ -214,6 +215,10 @@ automatically created having this form: 'auto-yyyymmdd-hhmmss'. If no \fB\-o, \-\-output\fP is specified, the traces will be written in $HOME/lttng-traces. + +The $HOME environment variable can be overridden by defining the environment +variable LTTNG_HOME. This is useful when the user running the commands has +a non-writeable home directory. .fi .B OPTIONS: @@ -304,8 +309,11 @@ If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngr file. It is important to note that if a certain type of buffers is used, the session -will be set with that type and all other subsequent channel need to have the +will be set with that type and all other subsequent channel needs to have the same type. + +For the kernel tracer (\-k), once the session is started at least once, it's +not possible anymore to enable new channel for that session. .fi .B OPTIONS: @@ -327,17 +335,25 @@ same type. \-\-overwrite Flight recorder mode : overwrites events when subbuffers are full \-\-subbuf-size SIZE - Subbuffer size in bytes {+k,+M,+G} (default: 4096, kernel default: 262144) + Subbuffer size in bytes {+k,+M,+G} + (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) Rounded up to the next power of 2. + + The minimum subbuffer size, for each tracer, is the max value between + the default above and the system page size. You can issue this command + to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP \-\-num-subbuf NUM - Number of subbuffers (default: 4) + Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, metadata: 2) Rounded up to the next power of 2. \-\-switch-timer USEC - Switch subbuffer timer interval in µsec (default: 0) + Switch subbuffer timer interval in µsec. + (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) \-\-read-timer USEC - Read timer interval in µsec (UST default: 0, kernel default: 200000) + Read timer interval in µsec. + (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) \-\-output TYPE Channel output type. Possible values: mmap, splice + (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) \-\-buffers-uid Use per UID buffer (\-u only). Buffers are shared between applications that have the same UID. @@ -347,9 +363,10 @@ same type. Use shared buffer for the whole system (\-k only) \-C, \-\-tracefile-size SIZE Maximum size of each tracefile within a stream (in bytes). + 0 means unlimited. (default: 0) \-W, \-\-tracefile-count COUNT Used in conjunction with \-C option, this will limit the number - of files created to the specified count. + of files created to the specified count. 0 means unlimited. (default: 0) .B EXAMPLES: