Copyright 2010 Lennart Poettering
systemd 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
+ 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
- General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
bool on_ssd, on_btrfs;
struct statfs sfs;
usec_t not_after;
+ uint64_t previous_block_readahead;
+ bool previous_block_readahead_set = false;
assert(root);
- write_one_line_file("/proc/self/oom_score_adj", "1000");
+ if (asprintf(&pack_fn, "%s/.readahead", root) < 0) {
+ log_error("Out of memory");
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ /* If there's no pack file yet we lower the kernel readahead
+ * so that mincore() is accurate. If there is a pack file
+ * already we assume it is accurate enough so that kernel
+ * readahead is never triggered. */
+ previous_block_readahead_set =
+ access(pack_fn, F_OK) < 0 &&
+ block_get_readahead(root, &previous_block_readahead) >= 0 &&
+ block_set_readahead(root, 8*1024) >= 0;
if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)) < 0)
log_warning("Failed to set IDLE IO priority class: %m");
on_btrfs = statfs(root, &sfs) >= 0 && (long) sfs.f_type == (long) BTRFS_SUPER_MAGIC;
log_debug("On btrfs: %s", yes_no(on_btrfs));
- asprintf(&pack_fn, "%s/.readahead", root);
- asprintf(&pack_fn_new, "%s/.readahead.new", root);
-
- if (!pack_fn || !pack_fn_new) {
+ if (asprintf(&pack_fn_new, "%s/.readahead.new", root) < 0) {
log_error("Out of memory");
r = -ENOMEM;
goto finish;
fclose(pack);
unlink(pack_fn_new);
}
-
free(pack_fn_new);
free(pack_fn);
hashmap_free(files);
+ if (previous_block_readahead_set) {
+ uint64_t bytes;
+
+ /* Restore the original kernel readahead setting if we
+ * changed it, and nobody has overwritten it since
+ * yet. */
+ if (block_get_readahead(root, &bytes) >= 0 && bytes == 8*1024)
+ block_set_readahead(root, previous_block_readahead);
+ }
+
return r;
}
umask(0022);
- if ((r = parse_argv(argc, argv)) <= 0)
+ r = parse_argv(argc, argv);
+ if (r <= 0)
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
root = optind < argc ? argv[optind] : "/";
+ /* Skip this step on read-only media. Note that we check the
+ * underlying block device here, not he read-only flag of the
+ * file system on top, since that one is most likely mounted
+ * read-only anyway at boot, even if the underlying block
+ * device is theoretically writable. */
if (fs_on_read_only(root) > 0) {
log_info("Disabling readahead collector due to read-only media.");
return 0;
return 0;
}
- if (detect_virtualization(NULL) > 0) {
- log_info("Disabling readahead collector due to execution in virtualized environment.");
- return 0;
- }
-
- if (!(shared = shared_get()))
+ shared = shared_get();
+ if (!shared)
return 1;
shared->collect = getpid();