blktrace: disable kill option - take 2
PATCH 1/1 blktrace: disable kill option - take 2
Fixup for 513950.
Problem:
'blktrace -d <device> -k' does not kill a running backgound trace. Executing 'blktrace -d <device> -k' for the second time results in "BLKTRACETEARDOWN:
Invalid argument" message and then each run of blktrace on that machine prints the following output:
BLKTRACESETUP: No such file or directory.
The bug:
The option -k results in clobbering information about running trace by kernel (blk_trace_remove), while resources (files open in debugfs by the running background blktrace) are not released.
Solution:
Update documentation:
Undocument the non-working "kill" option. Advise to send SIGINT signall via kill(1) to the running background blktrace for its correct termination.
--- blktrace.c | 1 - doc/blktrace.8 | 24 ++++-------------------- 2 files changed, 4 insertions(+), 21 deletions(-)
blktrace.c +0 -1
@@ -442,7 +442,6 @@ static char usage_str[] = \"\t-r Path to mounted debugfs, defaults to /sys/kernel/debug\n" \"\t-o File(s) to send output to\n" \"\t-D Directory to prepend to output file names\n" \ -"\t-k Kill a running trace\n" \"\t-w Stop after defined time, in seconds\n" \"\t-a Only trace specified actions. See documentation\n" \"\t-A Give trace mask as a single value. See documentation\n" \
doc/blktrace.8 +4 -20
@@ -66,19 +66,10 @@ blktrace may also be run concurrently wi .TP 2 \- The default behaviour for blktrace is to run forever until explicitly -killed by the user (via a control-C, or kill utility invocation). -There are two ways to modify this: - -.TP 5 - 1. -You may utilise the blktrace utility itself to kill -a running trace -- via the \fB\-k\fR option. - -.TP 5 - 2. -You can specify a run-time duration for blktrace via the -\fB\-w\fR option -- then blktrace will run for the specified number -of seconds, and then halt. +killed by the user (via a control-C, or sending SIGINT signal to the +process via invocation the kill (1) utility). Also you can specify a +run-time duration for blktrace via the \fB\-w\fR option -- then +blktrace will run for the specified number of seconds, and then halt. .SH OPTIONS
@@ -119,13 +110,6 @@ Adds \fIdev\fR as a device to trace Adds the devices found in \fIfile\fR as devices to trace .RE -\-k -.br -\-\-kill -.RS -Kill on-going trace -.RE - \-n \fInum\-sub\fR .br \-\-num\-sub=\fInum-sub\fR
Jens Axboe
AppliedQuoted 18 lines · Edward Shishkin
Fixup for 513950.
Problem:
'blktrace -d <device> -k' does not kill a running backgound trace. Executing 'blktrace -d <device> -k' for the second time results in "BLKTRACETEARDOWN:
Invalid argument" message and then each run of blktrace on that machine prints the following output:
BLKTRACESETUP: No such file or directory.The bug:
The option -k results in clobbering information about running trace by kernel (blk_trace_remove), while resources (files open in debugfs by the running background blktrace) are not released.
Quoted 5 lines
Solution:
Update documentation:
Undocument the non-working "kill" option. Advise to send SIGINT signall via kill(1) to the running background blktrace for its correct termination.
Applied, thanks.
Signature · 1 line
Jens Axboe