1 files changed, 29 insertions, 27 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index bd50cdff08a8..768888b9326a 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -631,43 +631,45 @@ option. The -e option and this one can be mixed and matched.  Events
 can be grouped using the {} notation.
 endif::HAVE_LIBPFM[]
 
---control fd:ctl-fd[,ack-fd]
+--control=fifo:ctl-fifo[,ack-fifo]::
+--control=fd:ctl-fd[,ack-fd]::
+ctl-fifo / ack-fifo are opened and used as ctl-fd / ack-fd as follows.
 Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
-'disable': disable events). Measurements can be started with events disabled using
---delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor
-to synchronize with the controlling process. Example of bash shell script to enable and
-disable events during measurements:
+'disable': disable events, 'snapshot': AUX area tracing snapshot). Measurements can be
+started with events disabled using --delay=-1 option. Optionally send control command
+completion ('ack\n') to ack-fd descriptor to synchronize with the controlling process.
+Example of bash shell script to enable and disable events during measurements:
 
-#!/bin/bash
+ #!/bin/bash
 
-ctl_dir=/tmp/
+ ctl_dir=/tmp/
 
-ctl_fifo=${ctl_dir}perf_ctl.fifo
-test -p ${ctl_fifo} && unlink ${ctl_fifo}
-mkfifo ${ctl_fifo}
-exec {ctl_fd}<>${ctl_fifo}
+ ctl_fifo=${ctl_dir}perf_ctl.fifo
+ test -p ${ctl_fifo} && unlink ${ctl_fifo}
+ mkfifo ${ctl_fifo}
+ exec {ctl_fd}<>${ctl_fifo}
 
-ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
-test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
-mkfifo ${ctl_ack_fifo}
-exec {ctl_fd_ack}<>${ctl_ack_fifo}
+ ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
+ test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
+ mkfifo ${ctl_ack_fifo}
+ exec {ctl_fd_ack}<>${ctl_ack_fifo}
 
-perf record -D -1 -e cpu-cycles -a               \
-            --control fd:${ctl_fd},${ctl_fd_ack} \
-            -- sleep 30 &
-perf_pid=$!
+ perf record -D -1 -e cpu-cycles -a               \
+             --control fd:${ctl_fd},${ctl_fd_ack} \
+             -- sleep 30 &
+ perf_pid=$!
 
-sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
-sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
+ sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
+ sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
 
-exec {ctl_fd_ack}>&-
-unlink ${ctl_ack_fifo}
+ exec {ctl_fd_ack}>&-
+ unlink ${ctl_ack_fifo}
 
-exec {ctl_fd}>&-
-unlink ${ctl_fifo}
+ exec {ctl_fd}>&-
+ unlink ${ctl_fifo}
 
-wait -n ${perf_pid}
-exit $?
+ wait -n ${perf_pid}
+ exit $?
 
 
 SEE ALSO