Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [RFC PATCH 4/4] cgroups: Add an rlimit subsystem | Date | Mon, 20 Jun 2011 01:51:14 +0200 |
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Add a new rlimit subsystem with a first support to limit the number of tasks that can run inside a cgroup.
This is a step to be able to isolate a bit more a cgroup against the rest of the system and limit the global impact of a fork bomb or other resource abuse inside a given cgroup.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrew Morton <akpm@linux-foundation.org> --- include/linux/cgroup_subsys.h | 8 ++ init/Kconfig | 6 ++ kernel/Makefile | 1 + kernel/cgroup_rlim.c | 142 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 157 insertions(+), 0 deletions(-) create mode 100644 kernel/cgroup_rlim.c
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index ac663c1..aea8cd5 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -59,8 +59,16 @@ SUBSYS(net_cls) SUBSYS(blkio) #endif +/* */ + #ifdef CONFIG_CGROUP_PERF SUBSYS(perf) #endif /* */ + +#ifdef CONFIG_CGROUP_RLIM +SUBSYS(rlim) +#endif + +/* */ diff --git a/init/Kconfig b/init/Kconfig index 412c21b..1a48719 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -690,6 +690,12 @@ config CGROUP_MEM_RES_CTLR_SWAP_ENABLED select this option (if, for some reason, they need to disable it then noswapaccount does the trick). +config CGROUP_RLIM + bool "Rlimit on cgroups" + depends on RESOURCE_COUNTERS + help + This option enables the rlimit settings in the scope of a cgroup. + config CGROUP_PERF bool "Enable perf_event per-cpu per-container group (cgroup) monitoring" depends on PERF_EVENTS && CGROUPS diff --git a/kernel/Makefile b/kernel/Makefile index 2d64cfc..6713b38 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o +obj-$(CONFIG_CGROUP_RLIM) += cgroup_rlim.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_UTS_NS) += utsname.o obj-$(CONFIG_USER_NS) += user_namespace.o diff --git a/kernel/cgroup_rlim.c b/kernel/cgroup_rlim.c new file mode 100644 index 0000000..af69892 --- /dev/null +++ b/kernel/cgroup_rlim.c @@ -0,0 +1,142 @@ +/* + * Resource limits subsystem for cgroups + * + * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com> + * + * Thanks to Johannes Weiner for his suggestions on doing this and how to. + * + */ + +#include <linux/cgroup.h> +#include <linux/slab.h> +#include <linux/res_counter.h> + + +struct rlim { + struct res_counter proc_counter; + struct cgroup_subsys_state css; +}; + +static struct rlim root_rlim; + + +static inline struct rlim *cgroup_rlim(struct cgroup *cont) +{ + return container_of(cgroup_subsys_state(cont, rlim_subsys_id), + struct rlim, css); +} + +static struct cgroup_subsys_state * +rlim_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) +{ + struct rlim *rlim, *parent_rlim; + + if (!cgrp->parent) { + res_counter_init(&root_rlim.proc_counter, NULL); + return &root_rlim.css; + } + + rlim = kzalloc(sizeof(*rlim), GFP_KERNEL); + if (!rlim) + return ERR_PTR(-ENOMEM); + + parent_rlim = cgroup_rlim(cgrp->parent); + res_counter_init(&rlim->proc_counter, &parent_rlim->proc_counter); + + return &rlim->css; +} + +static void rlim_post_clone(struct cgroup_subsys *ss, struct cgroup *cgrp) +{ + struct rlim *rlim = cgroup_rlim(cgrp); + + res_counter_inherit(&rlim->proc_counter, RES_LIMIT); +} + +static void rlim_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cont) +{ + struct rlim *rlim = cgroup_rlim(cont); + + kfree(rlim); +} + +static void rlim_remove_proc(struct cgroup *cgrp) +{ + struct rlim *rlim = cgroup_rlim(cgrp); + + res_counter_uncharge(&rlim->proc_counter, 1); +} + +static void rlim_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct cgroup *old_cgrp, struct task_struct *task) +{ + rlim_remove_proc(old_cgrp); +} + +/* + * This is actually where we do the attachment. We need to check if we can + * attach and eventually attach all in once. + */ +static int rlim_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +{ + struct rlim *rlim = cgroup_rlim(cgrp); + struct res_counter *limit_fail_at; + + return res_counter_charge(&rlim->proc_counter, 1, &limit_fail_at); +} + +static void rlim_cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct task_struct *tsk) +{ + rlim_remove_proc(cgrp); +} + +static int rlim_fork(struct cgroup_subsys *ss, struct task_struct *task) +{ + struct cgroup_subsys_state *css = task->cgroups->subsys[rlim_subsys_id]; + struct cgroup *cgrp = css->cgroup; + + return rlim_can_attach_task(cgrp, task); +} + +static u64 max_proc_read_u64(struct cgroup *cont, struct cftype *cft) +{ + struct rlim *rlim = cgroup_rlim(cont); + + return res_counter_read_u64(&rlim->proc_counter, RES_LIMIT); +} + +static int max_proc_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) +{ + struct rlim *rlim = cgroup_rlim(cgrp); + + res_counter_write_u64(&rlim->proc_counter, RES_LIMIT, val); + + return 0; +} + +static struct cftype cft_max_proc = { + .name = "max_proc", + .read_u64 = max_proc_read_u64, + .write_u64 = max_proc_write_u64, +}; + +static int rlim_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) +{ + return cgroup_add_file(cgrp, ss, &cft_max_proc); +} + +struct cgroup_subsys rlim_subsys = { + .name = "rlim", + .subsys_id = rlim_subsys_id, + .create = rlim_cgroup_create, + .post_clone = rlim_post_clone, + .destroy = rlim_cgroup_destroy, + .exit = rlim_cgroup_exit, + .can_attach_task = rlim_can_attach_task, + .cancel_attach = rlim_cancel_attach, + .attach = rlim_cgroup_exit, + .fork = rlim_fork, + .populate = rlim_populate, + .early_init = 1, +}; -- 1.7.5.4
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