blob: 34b61ded08d0fa5e22527012c979e31163b1b8ec [file] [log] [blame]
/*
* Code related to setting up a blkio cgroup
*/
#include <stdio.h>
#include <stdlib.h>
#include <mntent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "fio.h"
#include "flist.h"
#include "cgroup.h"
#include "smalloc.h"
static struct fio_mutex *lock;
struct cgroup_member {
struct flist_head list;
char *root;
unsigned int cgroup_nodelete;
};
static char *find_cgroup_mnt(struct thread_data *td)
{
char *mntpoint = NULL;
struct mntent *mnt, dummy;
char buf[256] = {0};
FILE *f;
f = setmntent("/proc/mounts", "r");
if (!f) {
td_verror(td, errno, "setmntent /proc/mounts");
return NULL;
}
while ((mnt = getmntent_r(f, &dummy, buf, sizeof(buf))) != NULL) {
if (!strcmp(mnt->mnt_type, "cgroup") &&
strstr(mnt->mnt_opts, "blkio"))
break;
}
if (mnt)
mntpoint = smalloc_strdup(mnt->mnt_dir);
else
log_err("fio: cgroup blkio does not appear to be mounted\n");
endmntent(f);
return mntpoint;
}
static void add_cgroup(struct thread_data *td, const char *name,
struct flist_head *clist)
{
struct cgroup_member *cm;
if (!lock)
return;
cm = smalloc(sizeof(*cm));
if (!cm) {
err:
log_err("fio: failed to allocate cgroup member\n");
return;
}
INIT_FLIST_HEAD(&cm->list);
cm->root = smalloc_strdup(name);
if (!cm->root) {
sfree(cm);
goto err;
}
if (td->o.cgroup_nodelete)
cm->cgroup_nodelete = 1;
fio_mutex_down(lock);
flist_add_tail(&cm->list, clist);
fio_mutex_up(lock);
}
void cgroup_kill(struct flist_head *clist)
{
struct flist_head *n, *tmp;
struct cgroup_member *cm;
if (!lock)
return;
fio_mutex_down(lock);
flist_for_each_safe(n, tmp, clist) {
cm = flist_entry(n, struct cgroup_member, list);
if (!cm->cgroup_nodelete)
rmdir(cm->root);
flist_del(&cm->list);
sfree(cm->root);
sfree(cm);
}
fio_mutex_up(lock);
}
static char *get_cgroup_root(struct thread_data *td, char *mnt)
{
char *str = malloc(64);
if (td->o.cgroup)
sprintf(str, "%s%s%s", mnt, FIO_OS_PATH_SEPARATOR, td->o.cgroup);
else
sprintf(str, "%s%s%s", mnt, FIO_OS_PATH_SEPARATOR, td->o.name);
return str;
}
static int write_int_to_file(struct thread_data *td, const char *path,
const char *filename, unsigned int val,
const char *onerr)
{
char tmp[256];
FILE *f;
sprintf(tmp, "%s%s%s", path, FIO_OS_PATH_SEPARATOR, filename);
f = fopen(tmp, "w");
if (!f) {
td_verror(td, errno, onerr);
return 1;
}
fprintf(f, "%u", val);
fclose(f);
return 0;
}
static int cgroup_write_pid(struct thread_data *td, const char *root)
{
unsigned int val = td->pid;
return write_int_to_file(td, root, "tasks", val, "cgroup write pid");
}
/*
* Move pid to root class
*/
static int cgroup_del_pid(struct thread_data *td, char *mnt)
{
return cgroup_write_pid(td, mnt);
}
int cgroup_setup(struct thread_data *td, struct flist_head *clist, char **mnt)
{
char *root;
if (!*mnt) {
*mnt = find_cgroup_mnt(td);
if (!*mnt)
return 1;
}
/*
* Create container, if it doesn't exist
*/
root = get_cgroup_root(td, *mnt);
if (mkdir(root, 0755) < 0) {
int __e = errno;
if (__e != EEXIST) {
td_verror(td, __e, "cgroup mkdir");
log_err("fio: path %s\n", root);
goto err;
}
} else
add_cgroup(td, root, clist);
if (td->o.cgroup_weight) {
if (write_int_to_file(td, root, "blkio.weight",
td->o.cgroup_weight,
"cgroup open weight"))
goto err;
}
if (!cgroup_write_pid(td, root)) {
free(root);
return 0;
}
err:
free(root);
return 1;
}
void cgroup_shutdown(struct thread_data *td, char **mnt)
{
if (*mnt == NULL)
return;
if (!td->o.cgroup_weight && !td->o.cgroup)
return;
cgroup_del_pid(td, *mnt);
}
static void fio_init cgroup_init(void)
{
lock = fio_mutex_init(FIO_MUTEX_UNLOCKED);
if (!lock)
log_err("fio: failed to allocate cgroup lock\n");
}
static void fio_exit cgroup_exit(void)
{
fio_mutex_remove(lock);
}