On systems that have a mixed setup of cgroup and cgroup-v2, blkio
controller might be active. I think in this case there is no point in
using cgroup-v2. One needs to boot with cgroup_no_v1=blkio to be able
to use cgroup-v2 IO controller.
Signed-off-by: Andreas Herrmann <aherrmann@xxxxxxxx>
---
cgroup.c | 58 ++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/cgroup.c b/cgroup.c
index 77e31a4d..fc31d4cd 100644
--- a/cgroup.c
+++ b/cgroup.c
@@ -20,11 +20,10 @@ struct cgroup_member {
static struct cgroup_mnt *find_cgroup_mnt(struct thread_data *td)
{
- struct cgroup_mnt *cgroup_mnt = NULL;
+ struct cgroup_mnt *cgroup_mnt, *cg1_mnt = NULL, *cg2_mnt = NULL;
struct mntent *mnt, dummy;
char buf[256] = {0};
FILE *f;
- bool cgroup2 = false;
f = setmntent("/proc/mounts", "r");
if (!f) {
@@ -34,27 +33,50 @@ static struct cgroup_mnt *find_cgroup_mnt(struct thread_data *td)
while ((mnt = getmntent_r(f, &dummy, buf, sizeof(buf))) != NULL) {
if (!strcmp(mnt->mnt_type, "cgroup") &&
- strstr(mnt->mnt_opts, "blkio"))
- break;
- if (!strcmp(mnt->mnt_type, "cgroup2")) {
- cgroup2 = true;
+ strstr(mnt->mnt_opts, "blkio")) {
+ cg1_mnt = smalloc(sizeof(*cg1_mnt));
+ if (cg1_mnt) {
+ cg1_mnt->path = smalloc_strdup(mnt->mnt_dir);
+ if (!cg1_mnt->path) {
+ sfree(cg1_mnt);
+ cg1_mnt = NULL;
+ log_err("fio: could not allocate memory\n");
+ }
+ }
+ /*
+ * blkio controller has precedence
+ */
break;
+ } if (!strcmp(mnt->mnt_type, "cgroup2")) {
+ if (cg2_mnt)
+ continue;
+ cg2_mnt = smalloc(sizeof(*cg2_mnt));
+ if (cg2_mnt) {
+ cg2_mnt->path = smalloc_strdup(mnt->mnt_dir);
+ if (!cg2_mnt->path) {
+ sfree(cg2_mnt);
+ cg2_mnt = NULL;
+ log_err("fio: could not allocate memory\n");
+ } else
+ cg2_mnt->cgroup2 = true;
+ }
+ /*
+ * Check all mount points, there can be a mix
+ * of cgroup-v1 and cgroup-v2
+ */
+ continue;
}
}
- if (mnt) {
- cgroup_mnt = smalloc(sizeof(*cgroup_mnt));
- if (cgroup_mnt) {
- cgroup_mnt->path = smalloc_strdup(mnt->mnt_dir);
- if (!cgroup_mnt->path) {
- sfree(cgroup_mnt);
- log_err("fio: could not allocate memory\n");
- } else {
- cgroup_mnt->cgroup2 = cgroup2;
- }
- }
+ cgroup_mnt = NULL;
+ if (cg1_mnt) {
+ cgroup_mnt = cg1_mnt;
+ if (cg2_mnt)
+ sfree(cg2_mnt);
+ } else if (cg2_mnt) {
+ cgroup_mnt = cg2_mnt;
} else {
- log_err("fio: cgroup blkio does not appear to be mounted\n");
+ log_err("fio: cgroup blkio or cgroup2 do not appear to be mounted\n");
}
endmntent(f);
--
2.28.0
