From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 17 Nov 2010 20:27:53 +0000 (+0100)
Subject: cgroup: by default, duplicate service cgroup in the cpu hierarchy
X-Git-Tag: v13~18
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=d686d8a97bd7945af0a61504392d01a3167b576f;hp=74fe1fe36e35a26d764f1e3119d5f6d014db573c

cgroup: by default, duplicate service cgroup in the cpu hierarchy
---

diff --git a/src/cgroup.c b/src/cgroup.c
index 57c9c9e99..64082d0dc 100644
--- a/src/cgroup.c
+++ b/src/cgroup.c
@@ -46,7 +46,7 @@ int cgroup_bonding_realize(CGroupBonding *b) {
 
         b->realized = true;
 
-        if (b->only_us && b->clean_up)
+        if (b->ours)
                 cg_trim(b->controller, b->path, false);
 
         return 0;
@@ -57,7 +57,7 @@ int cgroup_bonding_realize_list(CGroupBonding *first) {
         int r;
 
         LIST_FOREACH(by_unit, b, first)
-                if ((r = cgroup_bonding_realize(b)) < 0)
+                if ((r = cgroup_bonding_realize(b)) < 0 && b->essential)
                         return r;
 
         return 0;
@@ -71,16 +71,18 @@ void cgroup_bonding_free(CGroupBonding *b) {
 
                 LIST_REMOVE(CGroupBonding, by_unit, b->unit->meta.cgroup_bondings, b);
 
-                assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path));
-                LIST_REMOVE(CGroupBonding, by_path, f, b);
+                if (streq(b->controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                        assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path));
+                        LIST_REMOVE(CGroupBonding, by_path, f, b);
 
-                if (f)
-                        hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f);
-                else
-                        hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path);
+                        if (f)
+                                hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f);
+                        else
+                                hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path);
+                }
         }
 
-        if (b->realized && b->only_us && b->clean_up) {
+        if (b->realized && b->ours) {
 
                 if (cgroup_bonding_is_empty(b) > 0)
                         cg_delete(b->controller, b->path);
@@ -103,7 +105,7 @@ void cgroup_bonding_free_list(CGroupBonding *first) {
 void cgroup_bonding_trim(CGroupBonding *b, bool delete_root) {
         assert(b);
 
-        if (b->realized && b->only_us && b->clean_up)
+        if (b->realized && b->ours)
                 cg_trim(b->controller, b->path, delete_root);
 }
 
@@ -132,22 +134,19 @@ int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) {
         int r;
 
         LIST_FOREACH(by_unit, b, first)
-                if ((r = cgroup_bonding_install(b, pid)) < 0)
+                if ((r = cgroup_bonding_install(b, pid)) < 0 && b->essential)
                         return r;
 
         return 0;
 }
 
 int cgroup_bonding_kill(CGroupBonding *b, int sig, Set *s) {
-        int r;
-
         assert(b);
         assert(sig >= 0);
 
-        if ((r = cgroup_bonding_realize(b)) < 0)
-                return r;
-
-        assert(b->realized);
+        /* Don't kill cgroups that aren't ours */
+        if (!b->realized || !b->ours)
+                return 0;
 
         return cg_kill_recursive(b->controller, b->path, sig, true, false, s);
 }
@@ -196,7 +195,7 @@ int cgroup_bonding_is_empty(CGroupBonding *b) {
                 return 1;
 
         /* It's not only us using this cgroup, so we just don't know */
-        return b->only_us ? 0 : -EAGAIN;
+        return b->ours ? 0 : -EAGAIN;
 }
 
 int cgroup_bonding_is_empty_list(CGroupBonding *first) {
@@ -372,7 +371,7 @@ Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) {
                 if (!b->unit)
                         continue;
 
-                if (b->only_us)
+                if (b->ours)
                         return b->unit;
         }
 
@@ -409,7 +408,7 @@ pid_t cgroup_bonding_search_main_pid(CGroupBonding *b) {
 
         assert(b);
 
-        if (!b->only_us)
+        if (!b->ours)
                 return 0;
 
         if ((r = cg_enumerate_processes(b->controller, b->path, &f)) < 0)
diff --git a/src/cgroup.h b/src/cgroup.h
index d6d5c86f1..89854ff34 100644
--- a/src/cgroup.h
+++ b/src/cgroup.h
@@ -39,11 +39,12 @@ struct CGroupBonding {
         /* For the Manager::cgroup_bondings hashmap */
         LIST_FIELDS(CGroupBonding, by_path);
 
-        /* When shutting down, remove cgroup? */
-        bool clean_up:1;
+        /* When shutting down, remove cgroup? Are our own tasks the
+         * only ones in this group?*/
+        bool ours:1;
 
-        /* When our tasks are the only ones in this group */
-        bool only_us:1;
+        /* If we cannot create this group, or add a process to it, is this fatal? */
+        bool essential:1;
 
         /* This cgroup is realized */
         bool realized:1;
diff --git a/src/mount.c b/src/mount.c
index 4094eef43..077ab9160 100644
--- a/src/mount.c
+++ b/src/mount.c
@@ -488,7 +488,7 @@ static int mount_load(Unit *u) {
                 if ((r = mount_add_target_links(m)) < 0)
                         return r;
 
-                if ((r = unit_add_default_cgroup(u)) < 0)
+                if ((r = unit_add_default_cgroups(u)) < 0)
                         return r;
 
                 if (m->meta.default_dependencies)
diff --git a/src/service.c b/src/service.c
index 023415170..429b53d4f 100644
--- a/src/service.c
+++ b/src/service.c
@@ -1055,7 +1055,7 @@ static int service_load(Unit *u) {
                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
                         return r;
 
-                if ((r = unit_add_default_cgroup(u)) < 0)
+                if ((r = unit_add_default_cgroups(u)) < 0)
                         return r;
 
 #ifdef HAVE_SYSV_COMPAT
diff --git a/src/socket.c b/src/socket.c
index 9662066c1..cb38ab3d6 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -344,7 +344,7 @@ static int socket_load(Unit *u) {
                 if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0)
                         return r;
 
-                if ((r = unit_add_default_cgroup(u)) < 0)
+                if ((r = unit_add_default_cgroups(u)) < 0)
                         return r;
 
                 if (s->meta.default_dependencies)
diff --git a/src/swap.c b/src/swap.c
index 6de79280c..ec9f157b1 100644
--- a/src/swap.c
+++ b/src/swap.c
@@ -289,7 +289,7 @@ static int swap_load(Unit *u) {
                 if ((r = swap_add_target_links(s)) < 0)
                         return r;
 
-                if ((r = unit_add_default_cgroup(u)) < 0)
+                if ((r = unit_add_default_cgroups(u)) < 0)
                         return r;
 
                 if (s->meta.default_dependencies)
diff --git a/src/unit.c b/src/unit.c
index edc636412..bfb1dd644 100644
--- a/src/unit.c
+++ b/src/unit.c
@@ -1682,7 +1682,6 @@ char *unit_dbus_path(Unit *u) {
 }
 
 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
-        CGroupBonding *l;
         int r;
 
         assert(u);
@@ -1697,12 +1696,16 @@ int unit_add_cgroup(Unit *u, CGroupBonding *b) {
         /* Ensure this hasn't been added yet */
         assert(!b->unit);
 
-        l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
-        LIST_PREPEND(CGroupBonding, by_path, l, b);
+        if (streq(b->controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                CGroupBonding *l;
 
-        if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
-                LIST_REMOVE(CGroupBonding, by_path, l, b);
-                return r;
+                l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
+                LIST_PREPEND(CGroupBonding, by_path, l, b);
+
+                if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
+                        LIST_REMOVE(CGroupBonding, by_path, l, b);
+                        return r;
+                }
         }
 
         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
@@ -1767,8 +1770,7 @@ int unit_add_cgroup_from_text(Unit *u, const char *name) {
 
         b->controller = controller;
         b->path = path;
-        b->only_us = false;
-        b->clean_up = false;
+        b->ours = false;
 
         if ((r = unit_add_cgroup(u, b)) < 0)
                 goto fail;
@@ -1783,35 +1785,51 @@ fail:
         return r;
 }
 
-int unit_add_default_cgroup(Unit *u) {
-        CGroupBonding *b;
+int unit_add_default_cgroups(Unit *u) {
+        CGroupBonding *b = NULL;
         int r = -ENOMEM;
+        const char * const default_controllers[] = {
+                SYSTEMD_CGROUP_CONTROLLER,
+                "cpu",
+                NULL
+        };
+        const char * const*c;
 
         assert(u);
 
-        /* Adds in the default cgroup data, if it wasn't specified yet */
+        /* Adds in the default cgroups, if it wasn't specified yet */
 
-        if (unit_get_default_cgroup(u))
-                return 0;
+        STRV_FOREACH(c, default_controllers) {
 
-        if (!(b = new0(CGroupBonding, 1)))
-                return -ENOMEM;
+                if (cgroup_bonding_find_list(u->meta.cgroup_bondings, *c))
+                        continue;
 
-        if (!(b->path = default_cgroup_path(u)))
-                goto fail;
+                if (!(b = new0(CGroupBonding, 1)))
+                        return -ENOMEM;
 
-        b->clean_up = true;
-        b->only_us = true;
+                if (!(b->path = default_cgroup_path(u)))
+                        goto fail;
 
-        if ((r = unit_add_cgroup(u, b)) < 0)
-                goto fail;
+                if (!(b->controller = strdup(*c)))
+                        goto fail;
+
+                b->ours = true;
+                b->essential = c == default_controllers; /* the first one is essential */
+
+                if ((r = unit_add_cgroup(u, b)) < 0)
+                        goto fail;
+
+                b = NULL;
+        }
 
         return 0;
 
 fail:
-        free(b->path);
-        free(b->controller);
-        free(b);
+        if (b) {
+                free(b->path);
+                free(b->controller);
+                free(b);
+        }
 
         return r;
 }
diff --git a/src/unit.h b/src/unit.h
index fbe88c2c7..9eda138fb 100644
--- a/src/unit.h
+++ b/src/unit.h
@@ -414,7 +414,7 @@ int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 
 int unit_add_cgroup(Unit *u, CGroupBonding *b);
 int unit_add_cgroup_from_text(Unit *u, const char *name);
-int unit_add_default_cgroup(Unit *u);
+int unit_add_default_cgroups(Unit *u);
 CGroupBonding* unit_get_default_cgroup(Unit *u);
 
 int unit_choose_id(Unit *u, const char *name);