--- /dev/null
+//po4a: entry man manual
+= fadvise(1)
+:doctype: manpage
+:man manual: User Commands
+:man source: util-linux {release-version}
+:page-layout: base
+:command: fadvise
+
+== NAME
+
+fadvise - utility to use the posix_fadvise system call
+
+== SYNOPSIS
+
+*fadvise* [*-a* _advice_] [*-o* _offset_] [*-l* _length_] _filename_
+
+*fadvise* [*-a* _advice_] [*-o* _offset_] [*-l* _length_] -d _file-descriptor_
+
+== DESCRIPTION
+
+*fadvise* is a simple command wrapping posix_fadvise system call
+that is for predeclaring an access pattern for file data.
+
+== OPTIONS
+
+*-d*, *--fd* _file-descriptor_::
+Apply the advice to the file specified with the file descriptor instead
+of open a file specified with a file name.
+
+*-a*, *--advice* _advice_::
+See the command output with *--help* option for available values for
+advice. If this option is omitted, "dontneed" is used as default advice.
+
+*-o*, *--offset* _offset_::
+Specifies the beginning offset of the range, in bytes.
+If this option is omitted, 0 is used as default advice.
+
+*-l*, *--length* _length_::
+Specifies the length of the range, in bytes.
+If this option is omitted, 0 is used as default advice.
+
+== AUTHORS
+
+mailto:yamato@redhat.com[Masatake YAMATO]
+
+== SEE ALSO
+
+*posix_fadvise*(2)
+
+include::man-common/bugreports.adoc[]
+
+include::man-common/footer.adoc[]
+
+ifdef::translation[]
+include::man-common/translation.adoc[]
+endif::[]
+
--- /dev/null
+/*
+ * fadvise - utility to use the posix_fadvise(2)
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All rights reserved.
+ * Written by Masatake YAMATO <yamato@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "c.h"
+#include "nls.h"
+#include "strutils.h"
+
+static const struct advice {
+ const char *name;
+ int num;
+} advices [] = {
+ { "normal", POSIX_FADV_NORMAL, },
+ { "sequential", POSIX_FADV_SEQUENTIAL, },
+ { "random", POSIX_FADV_RANDOM, },
+ { "noreuse", POSIX_FADV_NOREUSE, },
+ { "willneeded", POSIX_FADV_WILLNEED, },
+ { "dontneed", POSIX_FADV_DONTNEED, },
+};
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+ FILE *out = stdout;
+ size_t i;
+
+ fputs(USAGE_HEADER, out);
+ fprintf(out, _(" %s [options] file\n"), program_invocation_short_name);
+ fprintf(out, _(" %s [options] --fd|-d file-descriptor\n"), program_invocation_short_name);
+
+ fputs(USAGE_OPTIONS, out);
+ fputs(_(" -a, --advice <advice> applying advice to the file (default: \"dontneed\")\n"), out);
+ fputs(_(" -l, --length <num> length for range operations, in bytes\n"), out);
+ fputs(_(" -o, --offset <num> offset for range operations, in bytes\n"), out);
+
+ fputs(USAGE_SEPARATOR, out);
+ printf(USAGE_HELP_OPTIONS(23));
+
+ fputs(_("\nAvailable values for advice:\n"), out);
+ for (i = 0; i < ARRAY_SIZE(advices); i++) {
+ fprintf(out, " %s\n",
+ advices[i].name);
+ }
+
+ printf(USAGE_MAN_TAIL("fadvise(1)"));
+
+ exit(EXIT_SUCCESS);
+}
+
+struct fadvise_args {
+ int fd;
+ off_t offset;
+ off_t len;
+ int advice;
+};
+
+
+int main(int argc, char ** argv)
+{
+ int c;
+ int rc;
+ bool do_close = false;
+
+ int fd = -1;
+ off_t offset = 0;
+ off_t len = 0;
+ int advice = POSIX_FADV_DONTNEED;
+
+ static const struct option longopts[] = {
+ { "advice", required_argument, NULL, 'a' },
+ { "fd", required_argument, NULL, 'd' },
+ { "length", required_argument, NULL, 'l' },
+ { "offset", required_argument, NULL, 'o' },
+ { "version", no_argument, NULL, 'V' },
+ { "help", no_argument, NULL, 'h' },
+ { NULL, 0, NULL, 0 },
+ };
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+
+ while ((c = getopt_long (argc, argv, "a:d:hl:o:", longopts, NULL)) != -1) {
+ switch (c) {
+ case 'a':
+ break;
+ case 'd':
+ fd = strtos32_or_err(optarg,
+ _("invalid fd argument"));
+ break;
+ case 'l':
+ len = strtosize_or_err(optarg,
+ _("invalid length argument"));
+ break;
+ case 'o':
+ offset = strtosize_or_err(optarg,
+ _("invalid offset argument"));
+ break;
+ case 'V':
+ print_version(EXIT_SUCCESS);
+ case 'h':
+ usage();
+ default:
+ errtryhelp(EXIT_FAILURE);
+ }
+ }
+
+ if (optind == argc && fd == -1) {
+ warnx(_("no file specified"));
+ errtryhelp(EXIT_FAILURE);
+ }
+
+ if (argc - optind > 0 && fd != -1) {
+ warnx(_("specify either file descriptor or file name"));
+ errtryhelp(EXIT_FAILURE);
+ }
+
+ if (argc - optind > 1) {
+ warnx(_("specify one file descriptor or file name"));
+ errtryhelp(EXIT_FAILURE);
+ }
+
+ if (fd == -1) {
+ fd = open(argv[optind], O_RDONLY);
+ if (fd < 0)
+ err(EXIT_FAILURE, _("cannot open %s"), argv[optind]);
+ do_close = true;
+ }
+
+ rc = posix_fadvise(fd,
+ offset, len,
+ advice);
+ if (rc != 0)
+ warn(_("failed to advise"));
+
+ if (do_close)
+ close(fd);
+
+ return rc;
+}
--- /dev/null
+#!/bin/bash
+
+TS_TOPDIR="${0%/*}/../.."
+TS_DESC="drop page caches related to a file"
+
+. "$TS_TOPDIR"/functions.sh
+ts_init "$*"
+
+ts_check_test_command "$TS_CMD_FADVISE"
+ts_check_test_command "$TS_CMD_FINCORE"
+
+ts_check_prog "dd"
+ts_check_prog "sleep"
+
+ts_cd "$TS_OUTDIR"
+
+FILE="ddtest"
+BS=4k
+COUNT=8
+
+{
+ dd if=/dev/zero of="$FILE" bs=$BS count=$COUNT >& /dev/null
+ "$TS_CMD_FINCORE" "$FILE"
+ echo
+
+ dd if=/dev/zero of="$FILE" bs=$BS count=$COUNT >& /dev/null
+ echo "whole file"
+ "$TS_CMD_FADVISE" "$FILE"
+ echo status: $?
+ "$TS_CMD_FINCORE" "$FILE"
+ echo
+
+ dd if=/dev/zero of="$FILE" bs=$BS count=$COUNT >& /dev/null
+ echo "offset: 8192"
+ "$TS_CMD_FADVISE" -o 8192 "$FILE"
+ echo status: $?
+ "$TS_CMD_FINCORE" "$FILE"
+ echo
+
+ dd if=/dev/zero of="$FILE" bs=$BS count=$COUNT >& /dev/null
+ echo "length: 16384"
+ "$TS_CMD_FADVISE" -l 16384 "$FILE"
+ echo status: $?
+ "$TS_CMD_FINCORE" "$FILE"
+ echo
+
+ dd if=/dev/zero of="$FILE" bs=$BS count=$COUNT >& /dev/null
+ echo "offset: 8192, length: 16384 fd: 42"
+ "$TS_CMD_FADVISE" -o 8192 -l 16384 --fd 42 42<"$FILE"
+ echo status: $?
+ "$TS_CMD_FINCORE" "$FILE"
+ echo
+
+ rm "$FILE"
+} >> "$TS_OUTPUT" 2>> "$TS_ERRLOG"
+
+ts_finalize
projects / thirdparty / util-linux.git / commitdiff
