diff options
Diffstat (limited to 'kernel')
69 files changed, 6733 insertions, 2533 deletions
diff --git a/kernel/Kconfig.freezer b/kernel/Kconfig.freezer new file mode 100644 index 00000000000..a3bb4cb5253 --- /dev/null +++ b/kernel/Kconfig.freezer @@ -0,0 +1,2 @@ +config FREEZER + def_bool PM_SLEEP || CGROUP_FREEZER diff --git a/kernel/Makefile b/kernel/Makefile index 4e1d7df7c3e..305f11dbef2 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -24,6 +24,7 @@ CFLAGS_REMOVE_sched_clock.o = -pg CFLAGS_REMOVE_sched.o = -mno-spe -pg endif +obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o @@ -55,6 +56,7 @@ obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o +obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o @@ -83,6 +85,7 @@ obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_MARKERS) += marker.o +obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o obj-$(CONFIG_FTRACE) += trace/ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8c6e1c17e6d..046c1609606 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -241,7 +241,6 @@ static void unlink_css_set(struct css_set *cg) struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; - write_lock(&css_set_lock); hlist_del(&cg->hlist); css_set_count--; @@ -251,16 +250,25 @@ static void unlink_css_set(struct css_set *cg) list_del(&link->cgrp_link_list); kfree(link); } - - write_unlock(&css_set_lock); } -static void __release_css_set(struct kref *k, int taskexit) +static void __put_css_set(struct css_set *cg, int taskexit) { int i; - struct css_set *cg = container_of(k, struct css_set, ref); - + /* + * Ensure that the refcount doesn't hit zero while any readers + * can see it. Similar to atomic_dec_and_lock(), but for an + * rwlock + */ + if (atomic_add_unless(&cg->refcount, -1, 1)) + return; + write_lock(&css_set_lock); + if (!atomic_dec_and_test(&cg->refcount)) { + write_unlock(&css_set_lock); + return; + } unlink_css_set(cg); + write_unlock(&css_set_lock); rcu_read_lock(); for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { @@ -276,32 +284,22 @@ static void __release_css_set(struct kref *k, int taskexit) kfree(cg); } -static void release_css_set(struct kref *k) -{ - __release_css_set(k, 0); -} - -static void release_css_set_taskexit(struct kref *k) -{ - __release_css_set(k, 1); -} - /* * refcounted get/put for css_set objects */ static inline void get_css_set(struct css_set *cg) { - kref_get(&cg->ref); + atomic_inc(&cg->refcount); } static inline void put_css_set(struct css_set *cg) { - kref_put(&cg->ref, release_css_set); + __put_css_set(cg, 0); } static inline void put_css_set_taskexit(struct css_set *cg) { - kref_put(&cg->ref, release_css_set_taskexit); + __put_css_set(cg, 1); } /* @@ -427,7 +425,7 @@ static struct css_set *find_css_set( return NULL; } - kref_init(&res->ref); + atomic_set(&res->refcount, 1); INIT_LIST_HEAD(&res->cg_links); INIT_LIST_HEAD(&res->tasks); INIT_HLIST_NODE(&res->hlist); @@ -870,6 +868,14 @@ static struct super_operations cgroup_ops = { .remount_fs = cgroup_remount, }; +static void init_cgroup_housekeeping(struct cgroup *cgrp) +{ + INIT_LIST_HEAD(&cgrp->sibling); + INIT_LIST_HEAD(&cgrp->children); + INIT_LIST_HEAD(&cgrp->css_sets); + INIT_LIST_HEAD(&cgrp->release_list); + init_rwsem(&cgrp->pids_mutex); +} static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; @@ -878,10 +884,7 @@ static void init_cgroup_root(struct cgroupfs_root *root) root->number_of_cgroups = 1; cgrp->root = root; cgrp->top_cgroup = cgrp; - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); } static int cgroup_test_super(struct super_block *sb, void *data) @@ -1728,7 +1731,7 @@ int cgroup_task_count(const struct cgroup *cgrp) read_lock(&css_set_lock); list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) { - count += atomic_read(&link->cg->ref.refcount); + count += atomic_read(&link->cg->refcount); } read_unlock(&css_set_lock); return count; @@ -1997,16 +2000,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * but we cannot guarantee that the information we produce is correct * unless we produce it entirely atomically. * - * Upon tasks file open(), a struct ctr_struct is allocated, that - * will have a pointer to an array (also allocated here). The struct - * ctr_struct * is stored in file->private_data. Its resources will - * be freed by release() when the file is closed. The array is used - * to sprintf the PIDs and then used by read(). */ -struct ctr_struct { - char *buf; - int bufsz; -}; /* * Load into 'pidarray' up to 'npids' of the tasks using cgroup @@ -2088,42 +2082,132 @@ static int cmppid(const void *a, const void *b) return *(pid_t *)a - *(pid_t *)b; } + /* - * Convert array 'a' of 'npids' pid_t's to a string of newline separated - * decimal pids in 'buf'. Don't write more than 'sz' chars, but return - * count 'cnt' of how many chars would be written if buf were large enough. + * seq_file methods for the "tasks" file. The seq_file position is the + * next pid to display; the seq_file iterator is a pointer to the pid + * in the cgroup->tasks_pids array. */ -static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids) + +static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) { - int cnt = 0; - int i; + /* + * Initially we receive a position value that corresponds to + * one more than the last pid shown (or 0 on the first call or + * after a seek to the start). Use a binary-search to find the + * next pid to display, if any + */ + struct cgroup *cgrp = s->private; + int index = 0, pid = *pos; + int *iter; - for (i = 0; i < npids; i++) - cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]); - return cnt; + down_read(&cgrp->pids_mutex); + if (pid) { + int end = cgrp->pids_length; + int i; + while (index < end) { + int mid = (index + end) / 2; + if (cgrp->tasks_pids[mid] == pid) { + index = mid; + break; + } else if (cgrp->tasks_pids[mid] <= pid) + index = mid + 1; + else + end = mid; + } + } + /* If we're off the end of the array, we're done */ + if (index >= cgrp->pids_length) + return NULL; + /* Update the abstract position to be the actual pid that we found */ + iter = cgrp->tasks_pids + index; + *pos = *iter; + return iter; +} + +static void cgroup_tasks_stop(struct seq_file *s, void *v) +{ + struct cgroup *cgrp = s->private; + up_read(&cgrp->pids_mutex); } +static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct cgroup *cgrp = s->private; + int *p = v; + int *end = cgrp->tasks_pids + cgrp->pids_length; + + /* + * Advance to the next pid in the array. If this goes off the + * end, we're done + */ + p++; + if (p >= end) { + return NULL; + } else { + *pos = *p; + return p; + } +} + +static int cgroup_tasks_show(struct seq_file *s, void *v) +{ + return seq_printf(s, "%d\n", *(int *)v); +} + +static struct seq_operations cgroup_tasks_seq_operations = { + .start = cgroup_tasks_start, + .stop = cgroup_tasks_stop, + .next = cgroup_tasks_next, + .show = cgroup_tasks_show, +}; + +static void release_cgroup_pid_array(struct cgroup *cgrp) +{ + down_write(&cgrp->pids_mutex); + BUG_ON(!cgrp->pids_use_count); + if (!--cgrp->pids_use_count) { + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = NULL; + cgrp->pids_length = 0; + } + up_write(&cgrp->pids_mutex); +} + +static int cgroup_tasks_release(struct inode *inode, struct file *file) +{ + struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); + + if (!(file->f_mode & FMODE_READ)) + return 0; + + release_cgroup_pid_array(cgrp); + return seq_release(inode, file); +} + +static struct file_operations cgroup_tasks_operations = { + .read = seq_read, + .llseek = seq_lseek, + .write = cgroup_file_write, + .release = cgroup_tasks_release, +}; + /* - * Handle an open on 'tasks' file. Prepare a buffer listing the + * Handle an open on 'tasks' file. Prepare an array containing the * process id's of tasks currently attached to the cgroup being opened. - * - * Does not require any specific cgroup mutexes, and does not take any. */ + static int cgroup_tasks_open(struct inode *unused, struct file *file) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - struct ctr_struct *ctr; pid_t *pidarray; int npids; - char c; + int retval; + /* Nothing to do for write-only files */ if (!(file->f_mode & FMODE_READ)) return 0; - ctr = kmalloc(sizeof(*ctr), GFP_KERNEL); - if (!ctr) - goto err0; - /* * If cgroup gets more users after we read count, we won't have * enough space - tough. This race is indistinguishable to the @@ -2131,57 +2215,31 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file) * show up until sometime later on. */ npids = cgroup_task_count(cgrp); - if (npids) { - pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); - if (!pidarray) - goto err1; - - npids = pid_array_load(pidarray, npids, cgrp); - sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - - /* Call pid_array_to_buf() twice, first just to get bufsz */ - ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1; - ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL); - if (!ctr->buf) - goto err2; - ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids); - - kfree(pidarray); - } else { - ctr->buf = NULL; - ctr->bufsz = 0; - } - file->private_data = ctr; - return 0; - -err2: - kfree(pidarray); -err1: - kfree(ctr); -err0: - return -ENOMEM; -} + pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); + if (!pidarray) + return -ENOMEM; + npids = pid_array_load(pidarray, npids, cgrp); + sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); -static ssize_t cgroup_tasks_read(struct cgroup *cgrp, - struct cftype *cft, - struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) -{ - struct ctr_struct *ctr = file->private_data; + /* + * Store the array in the cgroup, freeing the old + * array if necessary + */ + down_write(&cgrp->pids_mutex); + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = pidarray; + cgrp->pids_length = npids; + cgrp->pids_use_count++; + up_write(&cgrp->pids_mutex); - return simple_read_from_buffer(buf, nbytes, ppos, ctr->buf, ctr->bufsz); -} + file->f_op = &cgroup_tasks_operations; -static int cgroup_tasks_release(struct inode *unused_inode, - struct file *file) -{ - struct ctr_struct *ctr; - - if (file->f_mode & FMODE_READ) { - ctr = file->private_data; - kfree(ctr->buf); - kfree(ctr); + retval = seq_open(file, &cgroup_tasks_seq_operations); + if (retval) { + release_cgroup_pid_array(cgrp); + return retval; } + ((struct seq_file *)file->private_data)->private = cgrp; return 0; } @@ -2210,7 +2268,6 @@ static struct cftype files[] = { { .name = "tasks", .open = cgroup_tasks_open, - .read = cgroup_tasks_read, .write_u64 = cgroup_tasks_write, .release = cgroup_tasks_release, .private = FILE_TASKLIST, @@ -2300,10 +2357,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, mutex_lock(&cgroup_mutex); - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); cgrp->parent = parent; cgrp->root = parent->root; @@ -2495,8 +2549,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) int __init cgroup_init_early(void) { int i; - kref_init(&init_css_set.ref); - kref_get(&init_css_set.ref); + atomic_set(&init_css_set.refcount, 1); INIT_LIST_HEAD(&init_css_set.cg_links); INIT_LIST_HEAD(&init_css_set.tasks); INIT_HLIST_NODE(&init_css_set.hlist); diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c index c3dc3aba4c0..daca6209202 100644 --- a/kernel/cgroup_debug.c +++ b/kernel/cgroup_debug.c @@ -57,7 +57,7 @@ static u64 current_css_set_refcount_read(struct cgroup *cont, u64 count; rcu_read_lock(); - count = atomic_read(¤t->cgroups->ref.refcount); + count = atomic_read(¤t->cgroups->refcount); rcu_read_unlock(); return count; } @@ -90,7 +90,7 @@ static struct cftype files[] = { { .name = "releasable", .read_u64 = releasable_read, - } + }, }; static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c new file mode 100644 index 00000000000..e9505695449 --- /dev/null +++ b/kernel/cgroup_freezer.c @@ -0,0 +1,379 @@ +/* + * cgroup_freezer.c - control group freezer subsystem + * + * Copyright IBM Corporation, 2007 + * + * Author : Cedric Le Goater <clg@fr.ibm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include <linux/module.h> +#include <linux/cgroup.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/freezer.h> +#include <linux/seq_file.h> + +enum freezer_state { + CGROUP_THAWED = 0, + CGROUP_FREEZING, + CGROUP_FROZEN, +}; + +struct freezer { + struct cgroup_subsys_state css; + enum freezer_state state; + spinlock_t lock; /* protects _writes_ to state */ +}; + +static inline struct freezer *cgroup_freezer( + struct cgroup *cgroup) +{ + return container_of( + cgroup_subsys_state(cgroup, freezer_subsys_id), + struct freezer, css); +} + +static inline struct freezer *task_freezer(struct task_struct *task) +{ + return container_of(task_subsys_state(task, freezer_subsys_id), + struct freezer, css); +} + +int cgroup_frozen(struct task_struct *task) +{ + struct freezer *freezer; + enum freezer_state state; + + task_lock(task); + freezer = task_freezer(task); + state = freezer->state; + task_unlock(task); + + return state == CGROUP_FROZEN; +} + +/* + * cgroups_write_string() limits the size of freezer state strings to + * CGROUP_LOCAL_BUFFER_SIZE + */ +static const char *freezer_state_strs[] = { + "THAWED", + "FREEZING", + "FROZEN", +}; + +/* + * State diagram + * Transitions are caused by userspace writes to the freezer.state file. + * The values in parenthesis are state labels. The rest are edge labels. + * + * (THAWED) --FROZEN--> (FREEZING) --FROZEN--> (FROZEN) + * ^ ^ | | + * | \_______THAWED_______/ | + * \__________________________THAWED____________/ + */ + +struct cgroup_subsys freezer_subsys; + +/* Locks taken and their ordering + * ------------------------------ + * |