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author | Richard W.M. Jones <rjones@redhat.com> | 2009-05-01 11:18:44 +0100 |
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committer | Richard W.M. Jones <rjones@redhat.com> | 2009-05-01 11:18:44 +0100 |
commit | 2dc9e8a858b62830d15a8186fe575eb7903d2171 (patch) | |
tree | 24cabdc930f88d016db62b0f965667c07d08cfc3 | |
parent | ac286b26df1aabceca26dac66c325a3676ace4cc (diff) | |
download | libguestfs-2dc9e8a858b62830d15a8186fe575eb7903d2171.tar.gz libguestfs-2dc9e8a858b62830d15a8186fe575eb7903d2171.tar.xz libguestfs-2dc9e8a858b62830d15a8186fe575eb7903d2171.zip |
Added drop-caches command.
-rw-r--r-- | daemon/Makefile.am | 1 | ||||
-rw-r--r-- | daemon/dropcaches.c | 52 | ||||
-rwxr-xr-x | src/generator.ml | 14 |
3 files changed, 67 insertions, 0 deletions
diff --git a/daemon/Makefile.am b/daemon/Makefile.am index 9cec685b..569f1ecc 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -29,6 +29,7 @@ guestfsd_SOURCES = \ debug.c \ devsparts.c \ dir.c \ + dropcaches.c \ ext2.c \ file.c \ fsck.c \ diff --git a/daemon/dropcaches.c b/daemon/dropcaches.c new file mode 100644 index 00000000..82d95ee2 --- /dev/null +++ b/daemon/dropcaches.c @@ -0,0 +1,52 @@ +/* libguestfs - the guestfsd daemon + * Copyright (C) 2009 Red Hat Inc. + * + * 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 will 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> + +#include "daemon.h" +#include "actions.h" + +#define PROCFILE "/proc/sys/vm/drop_caches" + +int +do_drop_caches (int what) +{ + FILE *fp; + + sync (); + + fp = fopen (PROCFILE, "w"); + if (fp == NULL) { + reply_with_perror (PROCFILE); + return -1; + } + + fprintf (fp, "%d", what); + if (fclose (fp) == EOF) { + reply_with_perror (PROCFILE); + return -1; + } + + return 0; +} diff --git a/src/generator.ml b/src/generator.ml index bb550f1d..2ffe19da 100755 --- a/src/generator.ml +++ b/src/generator.ml @@ -1737,6 +1737,20 @@ recursively using the C<cp -a> command."); This moves a file from C<src> to C<dest> where C<dest> is either a destination filename or destination directory."); + ("drop_caches", (RErr, [Int "whattodrop"]), 90, [], + [InitEmpty, TestRun ( + [["drop_caches"; "3"]])], + "drop kernel page cache, dentries and inodes", + "\ +This instructs the guest kernel to drop its page cache, +and/or dentries and inode caches. The parameter C<whattodrop> +tells the kernel what precisely to drop, see +L<http://linux-mm.org/Drop_Caches> + +Setting C<whattodrop> to 3 should drop everything. + +This automatically calls L<sync(2)> before the operation, +so that the maximum guest memory is freed."); ] |