Add an option "cgroup_nodelete" to not delete cgroups after job completion

o Add an option cgroup_nodelete to not remove cgroups created by fio after
  the job completion. This can help a user in inspecting various cgroup
  files after fio job completion.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index 6c7f05b9efde3334e5260b4c86371216d43de3b3..922db2f06601cab8f346c84b4e448b0745bca7f1 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1036,6 +1036,12 @@ cgroup_weight=int        Set the weight of the cgroup to this value. See
                the documentation that comes with the kernel, allowed values
                are in the range of 100..1000.
 
+cgroup_nodelete=bool Normally fio will delete the cgroups it has created after
+               the job completion. To override this behavior and to leave
+               cgroups around after the job completion, set cgroup_nodelete=1.
+               This can be useful if one wants to inspect various cgroup
+               files after job completion. Default: false
+
 uid=int                Instead of running as the invoking user, set the user ID to
                this value before the thread/process does any work.
 

diff --git a/cgroup.c b/cgroup.c
index 14bbc57bd0862a46cac3ea0fbd9162288c77341f..0e3a71ebbfa75f57c9980ff6ba5c990b972d0c50 100644 (file)
--- a/cgroup.c
+++ b/cgroup.c
@@ -14,6 +14,7 @@ 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)
@@ -43,14 +44,16 @@ static char *find_cgroup_mnt(struct thread_data *td)
        return mntpoint;
 }
 
-static void add_cgroup(const char *name, struct flist_head *clist)
+static void add_cgroup(struct thread_data *td, const char *name,
+                       struct flist_head *clist)
 {
        struct cgroup_member *cm;
 
        cm = smalloc(sizeof(*cm));
        INIT_FLIST_HEAD(&cm->list);
        cm->root = smalloc_strdup(name);
-
+       if (td->o.cgroup_nodelete)
+               cm->cgroup_nodelete = 1;
        fio_mutex_down(lock);
        flist_add_tail(&cm->list, clist);
        fio_mutex_up(lock);
@@ -65,7 +68,8 @@ void cgroup_kill(struct flist_head *clist)
 
        flist_for_each_safe(n, tmp, clist) {
                cm = flist_entry(n, struct cgroup_member, list);
-               rmdir(cm->root);
+               if (!cm->cgroup_nodelete)
+                       rmdir(cm->root);
                flist_del(&cm->list);
                sfree(cm->root);
                sfree(cm);
@@ -144,7 +148,7 @@ int cgroup_setup(struct thread_data *td, struct flist_head *clist, char **mnt)
                        goto err;
                }
        } else
-               add_cgroup(root, clist);
+               add_cgroup(td, root, clist);
 
        if (td->o.cgroup_weight) {
                if (write_int_to_file(td, root, "blkio.weight",

diff --git a/fio.1 b/fio.1
index 5d0988b2cef496bfd8cd945aba0f332f04dee9ac..12146c873101726d42055d11a54bb53375161752 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -762,6 +762,12 @@ your system doesn't have it mounted, you can do so with:
 Set the weight of the cgroup to this value. See the documentation that comes
 with the kernel, allowed values are in the range of 100..1000.
 .TP
+.BI cgroup_nodelete \fR=\fPbool
+Normally fio will delete the cgroups it has created after the job completion.
+To override this behavior and to leave cgroups around after the job completion,
+set cgroup_nodelete=1. This can be useful if one wants to inspect various
+cgroup files after job completion. Default: false
+.TP
 .BI uid \fR=\fPint
 Instead of running as the invoking user, set the user ID to this value before
 the thread/process does any work.

diff --git a/fio.h b/fio.h
index 5038e4def239c6eaa50074549e97201cdd1a3770..5dc0352af65d50c1bd7c66ecb7cc38016bbb7b76 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -281,6 +281,7 @@ struct thread_options {
         */
        char *cgroup;
        unsigned int cgroup_weight;
+       unsigned int cgroup_nodelete;
 
        unsigned int uid;
        unsigned int gid;

diff --git a/options.c b/options.c
index 974df334a209f2af811496ee7976d82169dd576e..994f2a19567f5818a4223d4690cc8b025f13569f 100644 (file)
--- a/options.c
+++ b/options.c
@@ -1817,6 +1817,13 @@ static struct fio_option options[FIO_MAX_OPTS] = {
                .minval = 100,
                .maxval = 1000,
        },
+       {
+               .name   = "cgroup_nodelete",
+               .type   = FIO_OPT_BOOL,
+               .off1   = td_var_offset(cgroup_nodelete),
+               .help   = "Do not delete cgroups after job completion",
+               .def    = "0",
+       },
        {
                .name   = "uid",
                .type   = FIO_OPT_INT,