diff options
Diffstat (limited to 'kernel')
96 files changed, 9638 insertions, 9342 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 961379caf66..b8d4cd8ac0b 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -58,7 +58,6 @@ obj-$(CONFIG_KEXEC) += kexec.o obj-$(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 @@ -87,17 +86,15 @@ obj-$(CONFIG_RELAY) += relay.o obj-$(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-$(CONFIG_FUNCTION_TRACER) += trace/ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_X86_DS) += trace/ obj-$(CONFIG_RING_BUFFER) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o obj-$(CONFIG_SLOW_WORK) += slow-work.o -obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o +obj-$(CONFIG_PERF_EVENTS) += perf_event.o ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c7ece8f027f..7ccba4bc5e3 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -23,6 +23,7 @@ */ #include <linux/cgroup.h> +#include <linux/ctype.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/kernel.h> @@ -48,6 +49,8 @@ #include <linux/namei.h> #include <linux/smp_lock.h> #include <linux/pid_namespace.h> +#include <linux/idr.h> +#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */ #include <asm/atomic.h> @@ -60,6 +63,8 @@ static struct cgroup_subsys *subsys[] = { #include <linux/cgroup_subsys.h> }; +#define MAX_CGROUP_ROOT_NAMELEN 64 + /* * A cgroupfs_root represents the root of a cgroup hierarchy, * and may be associated with a superblock to form an active @@ -74,6 +79,9 @@ struct cgroupfs_root { */ unsigned long subsys_bits; + /* Unique id for this hierarchy. */ + int hierarchy_id; + /* The bitmask of subsystems currently attached to this hierarchy */ unsigned long actual_subsys_bits; @@ -94,6 +102,9 @@ struct cgroupfs_root { /* The path to use for release notifications. */ char release_agent_path[PATH_MAX]; + + /* The name for this hierarchy - may be empty */ + char name[MAX_CGROUP_ROOT_NAMELEN]; }; /* @@ -141,6 +152,10 @@ struct css_id { static LIST_HEAD(roots); static int root_count; +static DEFINE_IDA(hierarchy_ida); +static int next_hierarchy_id; +static DEFINE_SPINLOCK(hierarchy_id_lock); + /* dummytop is a shorthand for the dummy hierarchy's top cgroup */ #define dummytop (&rootnode.top_cgroup) @@ -201,6 +216,7 @@ struct cg_cgroup_link { * cgroup, anchored on cgroup->css_sets */ struct list_head cgrp_link_list; + struct cgroup *cgrp; /* * List running through cg_cgroup_links pointing at a * single css_set object, anchored on css_set->cg_links @@ -227,8 +243,11 @@ static int cgroup_subsys_init_idr(struct cgroup_subsys *ss); static DEFINE_RWLOCK(css_set_lock); static int css_set_count; -/* hash table for cgroup groups. This improves the performance to - * find an existing css_set */ +/* + * hash table for cgroup groups. This improves the performance to find + * an existing css_set. This hash doesn't (currently) take into + * account cgroups in empty hierarchies. + */ #define CSS_SET_HASH_BITS 7 #define CSS_SET_TABLE_SIZE (1 << CSS_SET_HASH_BITS) static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE]; @@ -248,48 +267,22 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) return &css_set_table[index]; } +static void free_css_set_rcu(struct rcu_head *obj) +{ + struct css_set *cg = container_of(obj, struct css_set, rcu_head); + kfree(cg); +} + /* We don't maintain the lists running through each css_set to its * task until after the first call to cgroup_iter_start(). This * reduces the fork()/exit() overhead for people who have cgroups * compiled into their kernel but not actually in use */ static int use_task_css_set_links __read_mostly; -/* When we create or destroy a css_set, the operation simply - * takes/releases a reference count on all the cgroups referenced - * by subsystems in this css_set. This can end up multiple-counting - * some cgroups, but that's OK - the ref-count is just a - * busy/not-busy indicator; ensuring that we only count each cgroup - * once would require taking a global lock to ensure that no - * subsystems moved between hierarchies while we were doing so. - * - * Possible TODO: decide at boot time based on the number of - * registered subsystems and the number of CPUs or NUMA nodes whether - * it's better for performance to ref-count every subsystem, or to - * take a global lock and only add one ref count to each hierarchy. - */ - -/* - * unlink a css_set from the list and free it - */ -static void unlink_css_set(struct css_set *cg) +static void __put_css_set(struct css_set *cg, int taskexit) { struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; - - hlist_del(&cg->hlist); - css_set_count--; - - list_for_each_entry_safe(link, saved_link, &cg->cg_links, - cg_link_list) { - list_del(&link->cg_link_list); - list_del(&link->cgrp_link_list); - kfree(link); - } -} - -static void __put_css_set(struct css_set *cg, int taskexit) -{ - int i; /* * Ensure that the refcount doesn't hit zero while any readers * can see it. Similar to atomic_dec_and_lock(), but for an @@ -302,21 +295,28 @@ static void __put_css_set(struct css_set *cg, int taskexit) 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++) { - struct cgroup *cgrp = rcu_dereference(cg->subsys[i]->cgroup); + /* This css_set is dead. unlink it and release cgroup refcounts */ + hlist_del(&cg->hlist); + css_set_count--; + + list_for_each_entry_safe(link, saved_link, &cg->cg_links, + cg_link_list) { + struct cgroup *cgrp = link->cgrp; + list_del(&link->cg_link_list); + list_del(&link->cgrp_link_list); if (atomic_dec_and_test(&cgrp->count) && notify_on_release(cgrp)) { if (taskexit) set_bit(CGRP_RELEASABLE, &cgrp->flags); check_for_release(cgrp); } + + kfree(link); } - rcu_read_unlock(); - kfree(cg); + + write_unlock(&css_set_lock); + call_rcu(&cg->rcu_head, free_css_set_rcu); } /* @@ -338,6 +338,78 @@ static inline void put_css_set_taskexit(struct css_set *cg) } /* + * compare_css_sets - helper function for find_existing_css_set(). + * @cg: candidate css_set being tested + * @old_cg: existing css_set for a task + * @new_cgrp: cgroup that's being entered by the task + * @template: desired set of css pointers in css_set (pre-calculated) + * + * Returns true if "cg" matches "old_cg" except for the hierarchy + * which "new_cgrp" belongs to, for which it should match "new_cgrp". + */ +static bool compare_css_sets(struct css_set *cg, + struct css_set *old_cg, + struct cgroup *new_cgrp, + struct cgroup_subsys_state *template[]) +{ + struct list_head *l1, *l2; + + if (memcmp(template, cg->subsys, sizeof(cg->subsys))) { + /* Not all subsystems matched */ + return false; + } + + /* + * Compare cgroup pointers in order to distinguish between + * different cgroups in heirarchies with no subsystems. We + * could get by with just this check alone (and skip the + * memcmp above) but on most setups the memcmp check will + * avoid the need for this more expensive check on almost all + * candidates. + */ + + l1 = &cg->cg_links; + l2 = &old_cg->cg_links; + while (1) { + struct cg_cgroup_link *cgl1, *cgl2; + struct cgroup *cg1, *cg2; + + l1 = l1->next; + l2 = l2->next; + /* See if we reached the end - both lists are equal length. */ + if (l1 == &cg->cg_links) { + BUG_ON(l2 != &old_cg->cg_links); + break; + } else { + BUG_ON(l2 == &old_cg->cg_links); + } + /* Locate the cgroups associated with these links. */ + cgl1 = list_entry(l1, struct cg_cgroup_link, cg_link_list); + cgl2 = list_entry(l2, struct cg_cgroup_link, cg_link_list); + cg1 = cgl1->cgrp; + cg2 = cgl2->cgrp; + /* Hierarchies should be linked in the same order. */ + BUG_ON(cg1->root != cg2->root); + + /* + * If this hierarchy is the hierarchy of the cgroup + * that's changing, then we need to check that this + * css_set points to the new cgroup; if it's any other + * hierarchy, then this css_set should point to the + * same cgroup as the old css_set. + */ + if (cg1->root == new_cgrp->root) { + if (cg1 != new_cgrp) + return false; + } else { + if (cg1 != cg2) + return false; + } + } + return true; +} + +/* * find_existing_css_set() is a helper for * find_css_set(), and checks to see whether an existing * css_set is suitable. @@ -378,10 +450,11 @@ static struct css_set *find_existing_css_set( hhead = css_set_hash(template); hlist_for_each_entry(cg, node, hhead, hlist) { - if (!me |