--- /dev/null
+From e04ef476fd330485e5a88c7018d29c55cf411fe2 Mon Sep 17 00:00:00 2001
+From: Richard W.M. Jones <rjones@redhat.com>
+Date: Tue, 5 Oct 2010 09:54:10 +0100
+Subject: [PATCH] Trace reads and writes to qemu block devices.
+
+NB: This patch is not suitable for nor intended to go upstream in
+its current form.
+
+When qemu opens a block device, this patch creates a trace file
+in /tmp with a name related to the block device. Reads and writes
+to the device cause lines to be written to the trace file:
+
+ S <total_sectors>
+ W <sector> <nb_sectors>
+ R <sector> <nb_sectors>
+
+'S' is the summary line, printed first which just tells you how
+many sectors are on the device.
+
+'W' and 'R' are writes and reads, for the range <sector> through
+to <sector> + <nb_sectors> - 1.
+---
+ block.c | 29 +++++++++++++++++++++++++++++
+ block_int.h | 3 +++
+ 2 files changed, 32 insertions(+), 0 deletions(-)
+
+diff --git a/block.c b/block.c
+index ebbc376..26ead5b 100644
+--- a/block.c
++++ b/block.c
+@@ -474,6 +474,23 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
+ goto free_and_fail;
+ }
+
++ /* Open trace file in /tmp based on filename. XXX */
++ size_t len = strlen (filename);
++ char *trace_file = qemu_malloc (10 + len);
++ snprintf (trace_file, 10 + len, "/tmp/%s.qtr", filename);
++ size_t i;
++ for (i = 5; i < 5 + len; ++i) {
++ if (trace_file[i] == '/')
++ trace_file[i] = '_';
++ }
++ bs->trace_fp = fopen (trace_file, "w");
++ if (bs->trace_fp) {
++ setlinebuf (bs->trace_fp);
++ fprintf (bs->trace_fp, "S %" PRIi64 "\n", bs->total_sectors);
++ } else {
++ perror (trace_file);
++ }
++
+ #ifndef _WIN32
+ if (bs->is_temporary) {
+ unlink(filename);
+@@ -665,6 +682,10 @@ void bdrv_close(BlockDriverState *bs)
+ bdrv_close(bs->file);
+ }
+
++ if (bs->trace_fp)
++ fclose (bs->trace_fp);
++ bs->trace_fp = NULL;
++
+ /* call the change callback */
+ bs->media_changed = 1;
+ if (bs->change_cb)
+@@ -1995,6 +2016,10 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
+ /* Update stats even though technically transfer has not happened. */
+ bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
+ bs->rd_ops ++;
++
++ if (bs->trace_fp)
++ fprintf (bs->trace_fp,
++ "R %" PRIi64 " %d\n", sector_num, nb_sectors);
+ }
+
+ return ret;
+@@ -2028,6 +2053,10 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+ if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
+ bs->wr_highest_sector = sector_num + nb_sectors - 1;
+ }
++
++ if (bs->trace_fp)
++ fprintf (bs->trace_fp,
++ "W %" PRIi64 " %d\n", sector_num, nb_sectors);
+ }
+
+ return ret;
+diff --git a/block_int.h b/block_int.h
+index e8e7156..03e7c9b 100644
+--- a/block_int.h
++++ b/block_int.h
+@@ -178,6 +178,9 @@ struct BlockDriverState {
+ uint64_t wr_ops;
+ uint64_t wr_highest_sector;
+
++ /* Trace to file. */
++ FILE *trace_fp;
++
+ /* Whether the disk can expand beyond total_sectors */
+ int growable;
+
+--
+1.7.3.1
+
--- /dev/null
+#!/usr/bin/ocamlrun /usr/bin/ocaml
+
+#use "topfind";;
+#require "extlib";;
+
+(* Convert *.qtr (qemu block device trace) to Postscript. By Richard
+ * W.M. Jones <rjones@redhat.com>.
+ *
+ * Note that we use ordinary OCaml ints, which means this program is
+ * limited to: ~1TB disks for 32 bit machines, or effectively unlimited
+ * for 64 bit machines.
+ *)
+
+open ExtList
+open Scanf
+open Printf
+
+type op = Read | Write
+
+(* If 'true' then print debug messages. *)
+let debug = false
+
+(* Width of each row (in sectors) in the output. *)
+let row_size = 64
+
+(* Desirable alignment (sectors). *)
+let alignment = 8
+
+(* Height (in 1/72 inch) of the final image. *)
+let height = 6.*.72.
+
+(* Width (in 1/72 inch) of the final image. *)
+let width = 6.*.72.
+
+(* Reserve at left for the sector number (comes out of width). *)
+let sn_width = 36.
+
+let input =
+ if Array.length Sys.argv = 2 then
+ Sys.argv.(1)
+ else
+ failwith "usage: tracetops filename.qtr"
+
+(* Read the input file. *)
+let nb_sectors, accesses =
+ let chan = open_in input in
+ let nb_sectors =
+ let summary = input_line chan in
+ if String.length summary < 1 || summary.[0] <> 'S' then
+ failwith (sprintf "%s: input is not a qemu block device trace file"
+ input);
+ sscanf summary "S %d" (fun x -> x) in
+
+ if nb_sectors mod row_size <> 0 then
+ failwith (sprintf "input nb_sectors (%d) not divisible by row size (%d)"
+ nb_sectors row_size);
+
+ (* Read the reads and writes from the remainder of the file. *)
+ let accesses = ref [] in
+ let rec loop () =
+ let line = input_line chan in
+ let rw, s, n = sscanf line "%c %d %d" (fun rw s n -> (rw, s, n)) in
+ let rw =
+ match rw with
+ | 'R' -> Read | 'W' -> Write
+ | c -> failwith
+ (sprintf "%s: error reading input: got '%c', expecting 'R' or 'W'"
+ input c) in
+ if n < 0 || s < 0 || s+n > nb_sectors then
+ failwith (sprintf "%s: s (%d), n (%d) out of range" input s n);
+ let aligned = s mod alignment = 0 && n mod alignment = 0 in
+ accesses := (rw, aligned, s, n) :: !accesses;
+ loop ()
+ in
+ (try loop () with
+ | End_of_file -> ()
+ | Scan_failure msg ->
+ failwith (sprintf "%s: error reading input: %s" input msg)
+ );
+ close_in chan;
+
+ let accesses = List.rev !accesses in
+
+ if debug then (
+ eprintf "%s: nb_sectors = %d, accesses = %d\n"
+ input nb_sectors (List.length accesses)
+ );
+
+ nb_sectors, accesses
+
+let ranges =
+ (* Given the number of sectors, make the row array. *)
+ let nr_rows = nb_sectors / row_size in
+ let rows = Array.make nr_rows false in
+
+ List.iter (
+ fun (_, _, s, n) ->
+ let i0 = s / row_size in
+ let i1 = (s+n-1) / row_size in
+ for i = i0 to i1 do rows.(i) <- true done;
+ ) accesses;
+
+ (* Coalesce rows into a list of ranges of rows we will draw. *)
+ let rows = Array.to_list rows in
+ let rows = List.mapi (fun i v -> (v, i)) rows in
+ let ranges =
+ (* When called, we are in the middle of a range which started at i0. *)
+ let rec loop i0 = function
+ | (false, _) :: (false, _) :: (true, i1) :: []
+ | _ :: (_, i1) :: []
+ | (_, i1) :: [] ->
+ [i0, i1]
+ | (false, _) :: (false, _) :: (true, _) :: rest
+ | (false, _) :: (true, _) :: rest
+ | (true, _) :: rest ->
+ loop i0 rest
+ | (false, i1) :: rest ->
+ let i1 = i1 - 1 in
+ let rest = List.dropwhile (function (v, _) -> not v) rest in
+ (match rest with
+ | [] -> [i0, i1]
+ | (_, i2) :: rest -> (i0, i1) :: loop i2 rest)
+ | [] -> assert false
+ in
+ loop 0 (List.tl rows) in
+
+ if debug then (
+ eprintf "%s: rows = %d (ranges = %d)\n" input nr_rows (List.length ranges);
+ List.iter (
+ fun (i0, i1) ->
+ eprintf " %d - %d (rows %d - %d)\n"
+ (i0 * row_size) ((i1 + 1) * row_size - 1) i0 i1
+ ) ranges
+ );
+
+ ranges
+
+(* Locate where we will draw the rows and cells in the final image. *)
+let iter_rows, mapxy, row_height, cell_width =
+ let nr_ranges = List.length ranges in
+ let nr_breaks = nr_ranges - 1 in
+ let nr_rows =
+ List.fold_left (+) 0 (List.map (fun (i0,i1) -> i1-i0+1) ranges) in
+ let nr_rnb = nr_rows + nr_breaks in
+ let row_height = height /. float nr_rnb in
+ let cell_width = (width -. sn_width) /. float row_size in
+
+ if debug then (
+ eprintf "number of rows and breaks = %d\n" nr_rnb;
+ eprintf "row_height x cell_width = %g x %g\n" row_height cell_width
+ );
+
+ (* Create a higher-order function to iterate over the rows. *)
+ let rec iter_rows f =
+ let rec loop row = function
+ | [] -> ()
+ | (i0,i1) :: rows ->
+ for i = i0 to i1 do
+ let y = float (row+i-i0) *. row_height in
+ f y (Some i)
+ done;
+ (* Call an extra time for the break. *)
+ let y = float (row+i1-i0+1) *. row_height in
+ if rows <> [] then f y None;
+ (* extra +1 here is to skip the break *)
+ loop (row+i1-i0+1+1) rows
+ in
+ loop 0 ranges
+ in
+
+ (* Create a hash which maps from the row number to the position
+ * where we draw the row. If the row is not drawn, the hash value
+ * is missing.
+ *)
+ let row_y = Hashtbl.create nr_rows in
+ iter_rows (
+ fun y ->
+ function
+ | Some i -> Hashtbl.replace row_y i y
+ | None -> ()
+ );
+
+ (* Create a function which maps from the sector number to the final
+ * position that we will draw it.
+ *)
+ let mapxy s =
+ let r = s / row_size in
+ let y = try Hashtbl.find row_y r with Not_found -> assert false in
+ let x = sn_width +. cell_width *. float (s mod row_size) in
+ x, y
+ in
+
+ iter_rows, mapxy, row_height, cell_width
+
+(* Start the PostScript file. *)
+let () =
+ printf "%%!PS-Adobe-3.0 EPSF-3.0\n";
+ printf "%%%%BoundingBox: -10 -10 %g %g\n"
+ (width +. 10.) (height +. row_height +. 20.);
+ printf "%%%%Creator: tracetops.ml (part of libguestfs)\n";
+ printf "%%%%Title: %s\n" input;
+ printf "%%%%LanguageLevel: 2\n";
+ printf "%%%%Pages: 1\n";
+ printf "%%%%Page: 1 1\n";
+ printf "\n";
+
+ printf "/min { 2 copy gt { exch } if pop } def\n";
+ printf "/max { 2 copy lt { exch } if pop } def\n";
+
+ (* Function for drawing cells. *)
+ printf "/cell {\n";
+ printf " newpath\n";
+ printf " moveto\n";
+ printf " %g 0 rlineto\n" cell_width;
+ printf " 0 %g rlineto\n" row_height;
+ printf " -%g 0 rlineto\n" cell_width;
+ printf " closepath\n";
+ printf " gsave fill grestore 0.75 setgray stroke\n";
+ printf "} def\n";
+
+ (* Define colours for different cell types. *)
+ printf "/unalignedread { 0.95 0.95 0 setrgbcolor } def\n";
+ printf "/unalignedwrite { 0.95 0 0 setrgbcolor } def\n";
+ printf "/alignedread { 0 0.95 0 setrgbcolor } def\n";
+ printf "/alignedwrite { 0 0 0.95 setrgbcolor } def\n";
+
+ (* Get width of text. *)
+ printf "/textwidth { stringwidth pop } def\n";
+
+ (* Draw the outline. *)
+ printf "/outline {\n";
+ printf " newpath\n";
+ printf " %g 0 moveto\n" sn_width;
+ printf " %g 0 lineto\n" width;
+ printf " %g %g lineto\n" width height;
+ printf " %g %g lineto\n" sn_width height;
+ printf " closepath\n";
+ printf " 0.5 setlinewidth 0.3 setgray stroke\n";
+ printf "} def\n";
+
+ (* Draw the outline breaks. *)
+ printf "/breaks {\n";
+ iter_rows (
+ fun y ->
+ function
+ | Some _ -> ()
+ | None ->
+ let f xmin xmax =
+ let yll = y +. row_height /. 3. -. 2. in
+ let ylr = y +. row_height /. 2. -. 2. in
+ let yur = y +. 2. *. row_height /. 3. in
+ let yul = y +. row_height /. 2. in
+ printf " newpath\n";
+ printf " %g %g moveto\n" xmin yll;
+ printf " %g %g lineto\n" xmax ylr;
+ printf " %g %g lineto\n" xmax yur;
+ printf " %g %g lineto\n" xmin yul;
+ printf " closepath\n";
+ printf " 1 setgray fill\n";
+ printf " newpath\n";
+ printf " %g %g moveto\n" xmin yll;
+ printf " %g %g lineto\n" xmax ylr;
+ printf " %g %g moveto\n" xmax yur;
+ printf " %g %g lineto\n" xmin yul;
+ printf " closepath\n";
+ printf " 0.5 setlinewidth 0.3 setgray stroke\n"
+ in
+ f (sn_width -. 6.) (sn_width +. 6.);
+ f (width -. 6.) (width +. 6.)
+ );
+ printf "} def\n";
+
+ (* Draw the labels. *)
+ printf "/labels {\n";
+ printf " /Courier findfont\n";
+ printf " 0.75 %g mul 10 min scalefont\n" row_height;
+ printf " setfont\n";
+ iter_rows (
+ fun y ->
+ function
+ | Some i ->
+ let sector = i * row_size in
+ printf " newpath\n";
+ printf " /s { (%d) } def\n" sector;
+ printf " %g s textwidth sub 4 sub %g moveto\n" sn_width (y +. 2.);
+ printf " s show\n"
+ | None -> ()
+ );
+ printf "} def\n";
+
+ (* Print the key. *)
+ printf "/key {\n";
+ printf " /Times-Roman findfont\n";
+ printf " 10. scalefont\n";
+ printf " setfont\n";
+ let x = sn_width and y = height +. 10. in
+ printf " unalignedwrite %g %g cell\n" x y;
+ let x = x +. cell_width +. 4. in
+ printf " newpath %g %g moveto (unaligned write) 0.3 setgray show\n" x y;
+ let x = x +. 72. in
+ printf " unalignedread %g %g cell\n" x y;
+ let x = x +. cell_width +. 4. in
+ printf " newpath %g %g moveto (unaligned read) 0.3 setgray show\n" x y;
+ let x = x +. 72. in
+ printf " alignedwrite %g %g cell\n" x y;
+ let x = x +. cell_width +. 4. in
+ printf " newpath %g %g moveto (aligned write) 0.3 setgray show\n" x y;
+ let x = x +. 72. in
+ printf " alignedread %g %g cell\n" x y;
+ let x = x +. cell_width +. 4. in
+ printf " newpath %g %g moveto (aligned read) 0.3 setgray show\n" x y;
+ printf "} def\n";
+
+ printf "\n"
+
+(* Draw the accesses. *)
+let () =
+ (* Sort the accesses so unaligned ones are displayed at the end (on
+ * top of aligned ones) and writes on top of reads. This isn't
+ * really perfect, but it'll do.
+ *)
+ let cmp (rw, aligned, s, n) (rw', aligned', s', n') =
+ let r = compare rw rw' (* Write later *) in
+ if r <> 0 then r else (
+ let r = compare aligned' aligned (* unaligned later *) in
+ if r <> 0 then r else
+ compare (n, s) (n', s')
+ )
+ in
+ let accesses = List.sort ~cmp accesses in
+
+ List.iter (
+ fun op ->
+ let col, s, n =
+ match op with
+ | Read, false, s, n ->
+ "unalignedread", s, n
+ | Write, false, s, n ->
+ "unalignedwrite", s, n
+ | Read, true, s, n ->
+ "alignedread", s, n
+ | Write, true, s, n ->
+ "alignedwrite", s, n in
+ for i = s to s+n-1 do
+ let x, y = mapxy i in
+ printf "%s %g %g cell\n" col x y
+ done;
+ printf "\n"
+ ) accesses
+
+(* Finish off the PostScript output. *)
+let () =
+ printf "outline breaks labels key\n";
+ printf "%%%%EOF\n"
git.annexia.org / libguestfs.git / commitdiff