[systemd-devel] [PATCH] readahead: Add tool to analyze the contents of the pack file.

[Kok, Auke-jan H]

whoops,

this won't work against tip, I'll have to respin.

Auke


On Sun, Jun 3, 2012 at 1:48 AM, Auke Kok <auke-jan.h.kok at intel.com> wrote:
> This patch adds code to compile 'systemd-readahead-analyze' and install
> it into $bindir.
>
> Use this program to parse the contents of the readahead pack file, or
> an arbitrary pack file and display which files are listed in it, and
> how much of the files are requested to be readahead.
>
> This code is not new - it's partially taken from sreadahead (formerly
> maintained by Arjan van der Ven and me, and was originally written
> by me), and adapted with the right bits to parse the systemd
> readahead pack files, which are slightly different in format.
>
> Signed-off-by: Auke Kok <auke-jan.h.kok at intel.com>
> ---
>  Makefile.am                       |    6 ++
>  src/readahead/readahead-analyze.c |  122 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 128 insertions(+)
>  create mode 100644 src/readahead/readahead-analyze.c
>
> diff --git a/Makefile.am b/Makefile.am
> index 597711e..ab5b67a 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -2407,6 +2407,9 @@ systemd_readahead_replay_LDADD = \
>        libsystemd-daemon.la \
>        libudev.la
>
> +systemd_readahead_analyze_SOURCES = \
> +       src/readahead/readahead-analyze.c
> +
>  pkginclude_HEADERS += \
>        src/systemd/sd-readahead.h
>
> @@ -2414,6 +2417,9 @@ rootlibexec_PROGRAMS += \
>        systemd-readahead-collect \
>        systemd-readahead-replay
>
> +bin_PROGRAMS += \
> +       systemd-readahead-analyze
> +
>  dist_systemunit_DATA += \
>        units/systemd-readahead-drop.service \
>        units/systemd-readahead-done.timer
> diff --git a/src/readahead/readahead-analyze.c b/src/readahead/readahead-analyze.c
> new file mode 100644
> index 0000000..944214b
> --- /dev/null
> +++ b/src/readahead/readahead-analyze.c
> @@ -0,0 +1,122 @@
> +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
> +
> +/***
> +  This file is part of systemd.
> +
> +  Copyright 2012 Auke Kok <auke-jan.h.kok at intel.com>
> +
> +  systemd is free software; you can redistribute it and/or modify it
> +  under the terms of the GNU Lesser General Public License as published by
> +  the Free Software Foundation; either version 2.1 of the License, or
> +  (at your option) any later version.
> +
> +  systemd is distributed in the hope that it will be useful, but
> +  WITHOUT ANY WARRANTY; without even the implied warranty of
> +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> +  Lesser General Public License for more details.
> +
> +  You should have received a copy of the GNU Lesser General Public License
> +  along with systemd; If not, see <http://www.gnu.org/licenses/>.
> +***/
> +
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <stdbool.h>
> +#include <unistd.h>
> +#include <inttypes.h>
> +#include <linux/limits.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <string.h>
> +
> +
> +int main(int argc, char *argv[])
> +{
> +        char line[1024];
> +        char path[PATH_MAX];
> +        FILE *pack;
> +        int a;
> +        int missing = 0;
> +        off_t size;
> +        long tsize = 0;
> +        uint32_t b;
> +        uint32_t c;
> +        struct stat st;
> +        int pagesize = getpagesize();
> +
> +        if (argc != 2)
> +                snprintf(path, PATH_MAX, "/.readahead");
> +        else
> +                snprintf(path, PATH_MAX, "%s", argv[1]);
> +
> +        pack = fopen(path, "r");
> +        if (!pack) {
> +                fprintf(stderr, "Pack file missing\n");
> +                exit(EXIT_FAILURE);
> +        }
> +
> +        if (!(fgets(line, sizeof(line), pack))) {
> +                fprintf(stderr, "Pack file corrupt\n");
> +                exit(EXIT_FAILURE);
> +        }
> +
> +        if ((a = getc(pack)) == EOF) {
> +                fprintf(stderr, "Pack file corrupt\n");
> +                exit(EXIT_FAILURE);
> +        }
> +
> +        fprintf(stdout, "   pct  sections     size: path\n");
> +        fprintf(stdout, "   ===  ========     ====: ====\n");
> +
> +        while(true) {
> +                int pages = 0;
> +                int sections = 0;
> +
> +                if (!fgets(path, sizeof(path), pack))
> +                        break; /* done */
> +
> +                path[strlen(path)-1] = 0;
> +
> +                while (true) {
> +                        if (fread(&b, sizeof(b), 1, pack) != 1  ||
> +                            fread(&c, sizeof(c), 1, pack) != 1) {
> +                                fprintf(stderr, "Pack file corrupt\n");
> +                                exit(EXIT_FAILURE);
> +                        }
> +                        if ((b == 0) && (c == 0))
> +                                break;
> +
> +                        /* Uncomment this to get all the chunks separately
> +                        fprintf(stdout, " %d: %d %d\n", sections, b, c);
> +                         */
> +
> +                        pages += (c - b);
> +                        sections++;
> +                }
> +
> +                if (stat(path, &st) == 0) {
> +                        if (sections == 0)
> +                                size = st.st_size;
> +                        else
> +                                size = pages * pagesize;
> +
> +                        tsize += size;
> +                        if (sections)
> +                                fprintf(stdout, "  %4d%% (%2d) %12ld: %s\n", (int)(size / st.st_size * 100.0), sections, (unsigned long)size, path);
> +                        else
> +                                fprintf(stdout, "  %4d%% (%2d) %12ld: %s\n", 100, 1, (unsigned long)size, path);
> +                } else {
> +                        fprintf(stdout, "  %4s%% (%2s) %12s: %s (MISSING)\n", "???", "??", "???", path);
> +                        missing++;
> +                }
> +
> +        }
> +
> +        fprintf(stdout, "\nHOST:    %s", line);
> +        fprintf(stdout, "TYPE:    %c\n", a);
> +        fprintf(stdout, "MISSING: %d\n", missing);
> +        fprintf(stdout, "TOTAL:   %ld\n", tsize);
> +
> +        exit(EXIT_SUCCESS);
> +}
> --
> 1.7.10
>