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-rw-r--r--README77
1 files changed, 61 insertions, 16 deletions
diff --git a/README b/README
index f419381..06ee153 100644
--- a/README
+++ b/README
@@ -24,8 +24,17 @@ The snapshots include the full git object database as well.
Usage
-----
-% blktrace -d <dev> [-o <output> -a <trace> [-a <trace>] -k]
- -a <trace> is one of: (use multiple -a options to get more)
+$ blktrace -d <dev> [ -r relay_path ] [ -o output ] [ -k ] [ -w time ]
+ [ -a action ] [ -A action mask ]
+
+ -d Use specified device. May also be given last after options.
+ -r Path to mounted relayfs, defaults to /relay.
+ -o File(s) to send output to.
+ -k Kill running trace.
+ -w Stop after defined time, in seconds.
+ -a Only trace specific actions (use more -a options to add actions).
+ Available actions are:
+
READ
WRITE
BARRIER
@@ -36,20 +45,56 @@ Usage
COMPLETE
FS
PC
- -k Kill a currently running trace.
- --- run task to generate load to be traced ---
- <SIGINT to kill>
- --- Generates:
- <output>_out.[0..ncpus] : Contains binary trace data
-
- % blkparse -i <input> [-o <output> -s -t]
- --- Generates:
- <output>.log : Contains formatted trace data, if
- output logging is added with the -o option. Otherwise, the
- output is sent to stdout. If the -s option is used, in
- addition to per-CPU stats, per process stats are shown as well.
- The -t option will provide individual io statistics, displaying
- things like completion time, queueing time, etc.
+
+ -A Give the trace mask directly as a number.
+
+$ blkparse -i <input> [ -o <output> ] [ -b rb_batch ] [ -s ] [ -t ] [ -q ]
+ [ -w start:stop ] [ -f output format ] [ -F format spec ]
+
+ -i Input file containing trace data, or '-' for stdin.
+ -o Output file. If not given, output is stdout.
+ -b stdin read batching.
+ -s Show per-program io statistics.
+ -t Track individual ios. Will tell you the time a request took to
+ get queued, to get dispatched, and to get completed.
+ -q Quiet. Don't display any stats at the end of the trace.
+ -w Only parse data between the given time interval in seconds. If
+ 'start' isn't given, blkparse defaults the start time to 0.
+ -f Output format. Customize the output format. The format field
+ identifiers are:
+
+ %a - Action
+ %c - CPU ID
+ %C - Task command name
+ %d - Direction (r/w)
+ %D - Device number
+ %e - Error number
+ %M - Major
+ %m - Minor
+ %n - Nblocks
+ %p - PID
+ %P - PDU
+ %s - Sequence number
+ %S - Sector number
+ %t - Time (wallclock - nanoseconds)
+ %T - Time (wallclock - seconds)
+ %u - Time (processing - microseconds)
+ %U - Unplug depth(
+
+ -F Format specification. The individual specifiers are:
+
+ B - Back merge
+ C - Complete
+ D - Issue
+ F - Front merge
+ G - Get request
+ M - Both front and back merge
+ P - Plug
+ Q - Queue
+ R - Requeue
+ S - Sleep requests
+ T - Unplug timer
+ U - Unplug IO
If you want to do live tracing, you can pipe the data between blktrace