From d742d2aadf357e5256a0d06196dbffcbf80294b2 Mon Sep 17 00:00:00 2001 From: Philippe Proulx Date: Fri, 28 Jul 2017 15:30:09 -0400 Subject: [PATCH] lttng-ust(3): reword and fix style of `LTTNG_UST_ALLOW_BLOCKING` variable Signed-off-by: Philippe Proulx Signed-off-by: Mathieu Desnoyers --- doc/man/lttng-ust.3.txt | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt index 9f9a1d53..5c9c9f5d 100644 --- a/doc/man/lttng-ust.3.txt +++ b/doc/man/lttng-ust.3.txt @@ -1293,11 +1293,15 @@ are located in a specific directory under `$LTTNG_HOME` (or `$HOME` if `$LTTNG_HOME` is not set). `LTTNG_UST_ALLOW_BLOCKING`:: - If set, allow application to retry event tracing when there's + If set, allow the application to retry event tracing when there's no space left for the event record in the sub-buffer, therefore effectively blocking the application until space is made available - or timeout is reached. This only has effect on channels with - `blocking-timeout` set. + or the configured timeout is reached. ++ +To allow an application to block during tracing, you also need to +specify a blocking timeout when you create a channel with the +nloption:--blocking-timeout option of the man:lttng-enable-channel(1) +command. + This option can be useful in workloads generating very large trace data throughput, where blocking the application is an acceptable trade-off to -- 2.34.1