See the updated doc for details.
From: Alan D. Brunelle <[EMAIL PROTECTED]>
Add in option to have seeks be start-to-start, rather than closest
Signed-off-by: Alan D. Brunelle <[EMAIL PROTECTED]>
---
btt/args.c | 11 ++++++++++-
btt/bt_timeline.c | 2 +-
btt/doc/btt.tex | 28 ++++++++++++++++++++++++++--
btt/globals.h | 2 +-
btt/seek.c | 19 ++++++++++++-------
5 files changed, 50 insertions(+), 12 deletions(-)
diff --git a/btt/args.c b/btt/args.c
index 9aa24ae..bc60faf 100644
--- a/btt/args.c
+++ b/btt/args.c
@@ -29,9 +29,15 @@
#define SETBUFFER_SIZE (64 * 1024)
-#define S_OPTS "AB:d:D:e:hi:I:l:M:o:p:q:s:S:t:T:Vv"
+#define S_OPTS "aAB:d:D:e:hi:I:l:M:o:p:q:s:S:t:T:Vv"
static struct option l_opts[] = {
{
+ .name = "seek-absolute",
+ .has_arg = no_argument,
+ .flag = NULL,
+ .val = 'a'
+ },
+ {
.name = "all-data",
.has_arg = no_argument,
.flag = NULL,
@@ -213,6 +219,9 @@ void handle_args(int argc, char *argv[])
while ((c = getopt_long(argc, argv, S_OPTS, l_opts, NULL)) != -1) {
switch (c) {
+ case 'a':
+ seek_absolute = 1;
+ break;
case 'A':
output_all_data = 1;
break;
diff --git a/btt/bt_timeline.c b/btt/bt_timeline.c
index d998e99..76676a3 100644
--- a/btt/bt_timeline.c
+++ b/btt/bt_timeline.c
@@ -30,7 +30,7 @@ char bt_timeline_version[] = "0.99.1";
char *devices, *exes, *input_name, *output_name, *seek_name, *bno_dump_name;
char *d2c_name, *q2c_name, *per_io_name;
FILE *ranges_ofp, *avgs_ofp, *per_io_ofp;
-int verbose, done, time_bounded, output_all_data;
+int verbose, done, time_bounded, output_all_data, seek_absolute;
double t_astart, t_aend;
unsigned long n_traces;
struct avgs_info all_avgs;
diff --git a/btt/doc/btt.tex b/btt/doc/btt.tex
index 07b2127..ced747d 100644
--- a/btt/doc/btt.tex
+++ b/btt/doc/btt.tex
@@ -1,5 +1,5 @@
\documentclass{article}
-\usepackage{epsfig}
+\usepackage{epsfig,placeins}
%
% Copyright (C) 2007 Alan D. Brunelle <[EMAIL PROTECTED]>
@@ -22,7 +22,7 @@
\title{\texttt{btt} User Guide}
\author{Alan D. Brunelle ([EMAIL PROTECTED])}
-\date{1 March 2007}
+\date{10 April 2007}
\begin{document}
\maketitle
@@ -591,11 +591,27 @@ Device: rrqm/s wrqm/s r/s w/s rsec/s
wsec/s
\epsfig{file=seek.eps,width=4.5in}
\caption{\label{fig:seek}Seek Chart}
\end{figure}
+ \FloatBarrier
+
+ The seek difference is calculated in one of two ways:
+
+ \begin{description}
+ \item[default] By default, the seek distance is calculated as the
+ \emph{closest} distance between the previous IO and this IO. The
+ concept of \emph{closeness} means that it could either be the
+ \emph{end} of the previous IO and the beginning of the next, or the
+ end of this IO and the start of the next.
+
+ \item[\texttt{-a}] If the \texttt{-a} or \texttt{seek-absolute}
+ option is specified, then the seek distance is simply the difference
+ between the start of the previous IO and the start of this IO.
+ \end{description}
\newpage\section{\label{sec:cmd-line}Command Line}
\begin{verbatim}
Usage: \texttt{btt} 0.99.1
+[ -a | --seek-absolute ]
[ -A | --all-data ]
[ -B <output name> | --dump-blocknos=<output name> ]
[ -d <seconds> | --range-delta=<seconds> ]
@@ -617,6 +633,14 @@ Usage: \texttt{btt} 0.99.1
[ -v | --verbose ]
\end{verbatim}
+\subsection{\label{sec:o-a}\texttt{--seek-absolute}/\texttt{-a}}
+
+ When specified on the command line, this directs btt to calculate seek
+ distances based solely upon the starting block addresses of succeeding
+ IOs. By default \texttt{btt} uses the concept of the closeness to either
+ the beginning or end of the previous IO. See section~\ref{sec:seek}
+ for more details about seek distances.
+
\subsection{\label{sec:o-A}\texttt{--all-data}/\texttt{-A}}
Normally \texttt{btt} will not print out verbose information
diff --git a/btt/globals.h b/btt/globals.h
index 912bb7c..ad50917 100644
--- a/btt/globals.h
+++ b/btt/globals.h
@@ -199,7 +199,7 @@ extern char *seek_name, *iostat_name, *d2c_name, *q2c_name,
*per_io_name;
extern char *bno_dump_name;
extern double range_delta;
extern FILE *ranges_ofp, *avgs_ofp, *iostat_ofp, *per_io_ofp;
-extern int verbose, done, time_bounded, output_all_data;
+extern int verbose, done, time_bounded, output_all_data, seek_absolute;
extern unsigned int n_devs;
extern unsigned long n_traces;
extern struct list_head all_devs, all_procs, retries, rmhd;
diff --git a/btt/seek.c b/btt/seek.c
index fb62714..b8a3d42 100644
--- a/btt/seek.c
+++ b/btt/seek.c
@@ -105,14 +105,19 @@ long long seek_dist(struct seeki *sip, struct io *iop)
long long dist;
long long start = BIT_START(iop), end = BIT_END(iop);
- /* Some overlap means no seek */
- if (((sip->last_start <= start) && (start <= sip->last_end)) ||
- ((sip->last_start <= end) && (end <= sip->last_end)))
- dist = 0;
- else if (start > sip->last_end)
- dist = start - sip->last_end;
- else
+ if (seek_absolute)
dist = start - sip->last_start;
+ else {
+ /* Some overlap means no seek */
+ if (((sip->last_start <= start) && (start <= sip->last_end)) ||
+ ((sip->last_start <= end) && (end <= sip->last_end)))
+ dist = 0;
+ else if (start > sip->last_end)
+ dist = start - sip->last_end;
+ else
+ dist = start - sip->last_start;
+
+ }
sip->last_start = start;
sip->last_end = end;
