#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/signal.h>
- #include <linux/fs_struct.h>
+ #include <linux/path.h>
#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/pid.h>
struct robust_list_head;
struct bio;
struct bts_tracer;
+ struct fs_struct;
/*
* List of flags we want to share for kernel threads,
extern unsigned long nr_active(void);
extern unsigned long nr_iowait(void);
+ extern unsigned long get_parent_ip(unsigned long addr);
+
struct seq_file;
struct cfs_rq;
struct task_group;
struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos);
extern unsigned int softlockup_panic;
-extern unsigned long sysctl_hung_task_check_count;
-extern unsigned long sysctl_hung_task_timeout_secs;
-extern unsigned long sysctl_hung_task_warnings;
extern int softlockup_thresh;
#else
static inline void softlockup_tick(void)
{
}
-static inline void spawn_softlockup_task(void)
-{
-}
static inline void touch_softlockup_watchdog(void)
{
}
}
#endif
+#ifdef CONFIG_DETECT_HUNG_TASK
+extern unsigned int sysctl_hung_task_panic;
+extern unsigned long sysctl_hung_task_check_count;
+extern unsigned long sysctl_hung_task_timeout_secs;
+extern unsigned long sysctl_hung_task_warnings;
+extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
+ struct file *filp, void __user *buffer,
+ size_t *lenp, loff_t *ppos);
+#endif
/* Attach to any functions which should be ignored in wchan output. */
#define __sched __attribute__((__section__(".sched.text")))
extern signed long schedule_timeout_interruptible(signed long timeout);
extern signed long schedule_timeout_killable(signed long timeout);
extern signed long schedule_timeout_uninterruptible(signed long timeout);
+ asmlinkage void __schedule(void);
asmlinkage void schedule(void);
+ extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
struct nsproxy;
struct user_namespace;
(mm)->hiwater_vm = (mm)->total_vm; \
} while (0)
- #define get_mm_hiwater_rss(mm) max((mm)->hiwater_rss, get_mm_rss(mm))
- #define get_mm_hiwater_vm(mm) max((mm)->hiwater_vm, (mm)->total_vm)
+ static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
+ {
+ return max(mm->hiwater_rss, get_mm_rss(mm));
+ }
+
+ static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
+ {
+ return max(mm->hiwater_vm, mm->total_vm);
+ }
extern void set_dumpable(struct mm_struct *mm, int value);
extern int get_dumpable(struct mm_struct *mm);
struct list_head cpu_timers[3];
- /* job control IDs */
-
- /*
- * pgrp and session fields are deprecated.
- * use the task_session_Xnr and task_pgrp_Xnr routines below
- */
-
- union {
- pid_t pgrp __deprecated;
- pid_t __pgrp;
- };
-
struct pid *tty_old_pgrp;
- union {
- pid_t session __deprecated;
- pid_t __session;
- };
-
/* boolean value for session group leader */
int leader;
struct rq *busiest, struct sched_domain *sd,
enum cpu_idle_type idle);
void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
+ int (*needs_post_schedule) (struct rq *this_rq);
void (*post_schedule) (struct rq *this_rq);
void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
u64 last_wakeup;
u64 avg_overlap;
+ u64 start_runtime;
+ u64 avg_wakeup;
+ u64 nr_migrations;
+
#ifdef CONFIG_SCHEDSTATS
u64 wait_start;
u64 wait_max;
u64 exec_max;
u64 slice_max;
- u64 nr_migrations;
u64 nr_migrations_cold;
u64 nr_failed_migrations_affine;
u64 nr_failed_migrations_running;
#endif
struct list_head tasks;
+ struct plist_node pushable_tasks;
struct mm_struct *mm, *active_mm;
/* ??? */
unsigned int personality;
unsigned did_exec:1;
+ unsigned in_execve:1; /* Tell the LSMs that the process is doing an
+ * execve */
pid_t pid;
pid_t tgid;
- #ifdef CONFIG_CC_STACKPROTECTOR
/* Canary value for the -fstack-protector gcc feature */
unsigned long stack_canary;
- #endif
+
/*
* pointers to (original) parent process, youngest child, younger sibling,
* older sibling, respectively. (p->father can be replaced with
/* ipc stuff */
struct sysv_sem sysvsem;
#endif
-#ifdef CONFIG_DETECT_SOFTLOCKUP
+#ifdef CONFIG_DETECT_HUNG_TASK
/* hung task detection */
- unsigned long last_switch_timestamp;
unsigned long last_switch_count;
#endif
/* CPU-specific state of this task */
int lockdep_depth;
unsigned int lockdep_recursion;
struct held_lock held_locks[MAX_LOCK_DEPTH];
+ gfp_t lockdep_reclaim_gfp;
#endif
/* journalling filesystem info */
int curr_ret_stack;
/* Stack of return addresses for return function tracing */
struct ftrace_ret_stack *ret_stack;
+ /* time stamp for last schedule */
+ unsigned long long ftrace_timestamp;
/*
* Number of functions that haven't been traced
* because of depth overrun.
#endif
};
+ /* Future-safe accessor for struct task_struct's cpus_allowed. */
+ #define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)
+
/*
* Priority of a process goes from 0..MAX_PRIO-1, valid RT
* priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
return rt_prio(p->prio);
}
- static inline void set_task_session(struct task_struct *tsk, pid_t session)
- {
- tsk->signal->__session = session;
- }
-
- static inline void set_task_pgrp(struct task_struct *tsk, pid_t pgrp)
- {
- tsk->signal->__pgrp = pgrp;
- }
-
static inline struct pid *task_pid(struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
return task->group_leader->pids[PIDTYPE_PID].pid;
}
+ /*
+ * Without tasklist or rcu lock it is not safe to dereference
+ * the result of task_pgrp/task_session even if task == current,
+ * we can race with another thread doing sys_setsid/sys_setpgid.
+ */
static inline struct pid *task_pgrp(struct task_struct *task)
{
return task->group_leader->pids[PIDTYPE_PGID].pid;
*
* see also pid_nr() etc in include/linux/pid.h
*/
+ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+ struct pid_namespace *ns);
static inline pid_t task_pid_nr(struct task_struct *tsk)
{
return tsk->pid;
}
- pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
+ static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
+ struct pid_namespace *ns)
+ {
+ return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
+ }
static inline pid_t task_pid_vnr(struct task_struct *tsk)
{
- return pid_vnr(task_pid(tsk));
+ return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
}
}
- static inline pid_t task_pgrp_nr(struct task_struct *tsk)
+ static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
+ struct pid_namespace *ns)
{
- return tsk->signal->__pgrp;
+ return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
}
- pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
-
static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
{
- return pid_vnr(task_pgrp(tsk));
+ return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
}
- static inline pid_t task_session_nr(struct task_struct *tsk)
+ static inline pid_t task_session_nr_ns(struct task_struct *tsk,
+ struct pid_namespace *ns)
{
- return tsk->signal->__session;
+ return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
}
- pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
-
static inline pid_t task_session_vnr(struct task_struct *tsk)
{
- return pid_vnr(task_session(tsk));
+ return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
}
+ /* obsolete, do not use */
+ static inline pid_t task_pgrp_nr(struct task_struct *tsk)
+ {
+ return task_pgrp_nr_ns(tsk, &init_pid_ns);
+ }
/**
* pid_alive - check that a task structure is not stale
return set_cpus_allowed_ptr(p, &new_mask);
}
+ /*
+ * Architectures can set this to 1 if they have specified
+ * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
+ * but then during bootup it turns out that sched_clock()
+ * is reliable after all:
+ */
+ #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+ extern int sched_clock_stable;
+ #endif
+
extern unsigned long long sched_clock(void);
extern void sched_clock_init(void);
/* Allocate a new mm structure and copy contents from tsk->mm */
extern struct mm_struct *dup_mm(struct task_struct *tsk);
- extern int copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
+ extern int copy_thread(unsigned long, unsigned long, unsigned long,
+ struct task_struct *, struct pt_regs *);
extern void flush_thread(void);
extern void exit_thread(void);
#define delay_group_leader(p) \
(thread_group_leader(p) && !thread_group_empty(p))
+ static inline int task_detached(struct task_struct *p)
+ {
+ return p->exit_signal == -1;
+ }
+
/*
* Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
extern void thread_info_cache_init(void);
+ #ifdef CONFIG_DEBUG_STACK_USAGE
+ static inline unsigned long stack_not_used(struct task_struct *p)
+ {
+ unsigned long *n = end_of_stack(p);
+
+ do { /* Skip over canary */
+ n++;
+ } while (!*n);
+
+ return (unsigned long)n - (unsigned long)end_of_stack(p);
+ }
+ #endif
+
/* set thread flags in other task's structures
* - see asm/thread_info.h for TIF_xxxx flags available
*/
extern int sched_group_set_rt_period(struct task_group *tg,
long rt_period_us);
extern long sched_group_rt_period(struct task_group *tg);
+ extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
#endif
#endif
+ extern int task_can_switch_user(struct user_struct *up,
+ struct task_struct *tsk);
+
#ifdef CONFIG_TASK_XACCT
static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
{
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PM) += power/
+ obj-$(CONFIG_FREEZER) += power/
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_KEXEC) += kexec.o
obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
+obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_FUNCTION_TRACER) += trace/
obj-$(CONFIG_TRACING) += trace/
obj-$(CONFIG_SMP) += sched_cpupri.o
+ obj-$(CONFIG_SLOW_WORK) += slow-work.o
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
+ #include <linux/fs_struct.h>
#include <trace/sched.h>
+ #include <linux/magic.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
{
struct task_struct *tsk;
struct thread_info *ti;
+ unsigned long *stackend;
+
int err;
prepare_to_copy(orig);
goto out;
setup_thread_stack(tsk, orig);
+ stackend = end_of_stack(tsk);
+ *stackend = STACK_END_MAGIC; /* for overflow detection */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
mm->free_area_cache = oldmm->mmap_base;
mm->cached_hole_size = ~0UL;
mm->map_count = 0;
- cpus_clear(mm->cpu_vm_mask);
+ cpumask_clear(mm_cpumask(mm));
mm->mm_rb = RB_ROOT;
rb_link = &mm->mm_rb.rb_node;
rb_parent = NULL;
tsk->min_flt = tsk->maj_flt = 0;
tsk->nvcsw = tsk->nivcsw = 0;
+#ifdef CONFIG_DETECT_HUNG_TASK
+ tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
+#endif
tsk->mm = NULL;
tsk->active_mm = NULL;
return retval;
}
- static struct fs_struct *__copy_fs_struct(struct fs_struct *old)
- {
- struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
- /* We don't need to lock fs - think why ;-) */
- if (fs) {
- atomic_set(&fs->count, 1);
- rwlock_init(&fs->lock);
- fs->umask = old->umask;
- read_lock(&old->lock);
- fs->root = old->root;
- path_get(&old->root);
- fs->pwd = old->pwd;
- path_get(&old->pwd);
- read_unlock(&old->lock);
- }
- return fs;
- }
-
- struct fs_struct *copy_fs_struct(struct fs_struct *old)
- {
- return __copy_fs_struct(old);
- }
-
- EXPORT_SYMBOL_GPL(copy_fs_struct);
-
static int copy_fs(unsigned long clone_flags, struct task_struct *tsk)
{
+ struct fs_struct *fs = current->fs;
if (clone_flags & CLONE_FS) {
- atomic_inc(¤t->fs->count);
+ /* tsk->fs is already what we want */
+ write_lock(&fs->lock);
+ if (fs->in_exec) {
+ write_unlock(&fs->lock);
+ return -EAGAIN;
+ }
+ fs->users++;
+ write_unlock(&fs->lock);
return 0;
}
- tsk->fs = __copy_fs_struct(current->fs);
+ tsk->fs = copy_fs_struct(fs);
if (!tsk->fs)
return -ENOMEM;
return 0;
atomic_set(&sig->live, 1);
init_waitqueue_head(&sig->wait_chldexit);
sig->flags = 0;
+ if (clone_flags & CLONE_NEWPID)
+ sig->flags |= SIGNAL_UNKILLABLE;
sig->group_exit_code = 0;
sig->group_exit_task = NULL;
sig->group_stop_count = 0;
p->default_timer_slack_ns = current->timer_slack_ns;
-#ifdef CONFIG_DETECT_SOFTLOCKUP
- p->last_switch_count = 0;
- p->last_switch_timestamp = 0;
-#endif
-
task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);
goto bad_fork_cleanup_mm;
if ((retval = copy_io(clone_flags, p)))
goto bad_fork_cleanup_namespaces;
- retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
+ retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
if (retval)
goto bad_fork_cleanup_io;
#endif
clear_all_latency_tracing(p);
- /* Our parent execution domain becomes current domain
- These must match for thread signalling to apply */
- p->parent_exec_id = p->self_exec_id;
-
/* ok, now we should be set up.. */
p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
p->pdeath_signal = 0;
set_task_cpu(p, smp_processor_id());
/* CLONE_PARENT re-uses the old parent */
- if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
+ if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
- else
+ p->parent_exec_id = current->parent_exec_id;
+ } else {
p->real_parent = current;
+ p->parent_exec_id = current->self_exec_id;
+ }
spin_lock(¤t->sighand->siglock);
p->signal->leader_pid = pid;
tty_kref_put(p->signal->tty);
p->signal->tty = tty_kref_get(current->signal->tty);
- set_task_pgrp(p, task_pgrp_nr(current));
- set_task_session(p, task_session_nr(current));
attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
attach_pid(p, PIDTYPE_SID, task_session(current));
list_add_tail_rcu(&p->tasks, &init_task.tasks);
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);
mmap_init();
}
{
struct fs_struct *fs = current->fs;
- if ((unshare_flags & CLONE_FS) &&
- (fs && atomic_read(&fs->count) > 1)) {
- *new_fsp = __copy_fs_struct(current->fs);
- if (!*new_fsp)
- return -ENOMEM;
- }
+ if (!(unshare_flags & CLONE_FS) || !fs)
+ return 0;
+
+ /* don't need lock here; in the worst case we'll do useless copy */
+ if (fs->users == 1)
+ return 0;
+
+ *new_fsp = copy_fs_struct(fs);
+ if (!*new_fsp)
+ return -ENOMEM;
return 0;
}
if (new_fs) {
fs = current->fs;
+ write_lock(&fs->lock);
current->fs = new_fs;
- new_fs = fs;
+ if (--fs->users)
+ new_fs = NULL;
+ else
+ new_fs = fs;
+ write_unlock(&fs->lock);
}
if (new_mm) {
bad_unshare_cleanup_fs:
if (new_fs)
- put_fs_struct(new_fs);
+ free_fs_struct(new_fs);
bad_unshare_cleanup_thread:
bad_unshare_out:
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
+ #include <linux/slow-work.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
/* Constants used for minimum and maximum */
- #if defined(CONFIG_DETECT_HUNG_TASK) || defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)
- static int one = 1;
- #endif
#ifdef CONFIG_DETECT_SOFTLOCKUP
static int sixty = 60;
static int neg_one = -1;
#endif
- #if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING)
- static int two = 2;
- #endif
-
static int zero;
+ static int __maybe_unused one = 1;
+ static int __maybe_unused two = 2;
static unsigned long one_ul = 1;
static int one_hundred = 100;
.extra1 = &neg_one,
.extra2 = &sixty,
},
+#endif
+#ifdef CONFIG_DETECT_HUNG_TASK
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "hung_task_panic",
+ .data = &sysctl_hung_task_panic,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
{
.ctl_name = CTL_UNNUMBERED,
.procname = "hung_task_check_count",
.data = &sysctl_hung_task_timeout_secs,
.maxlen = sizeof(unsigned long),
.mode = 0644,
- .proc_handler = &proc_doulongvec_minmax,
+ .proc_handler = &proc_dohung_task_timeout_secs,
.strategy = &sysctl_intvec,
},
{
.proc_handler = &scan_unevictable_handler,
},
#endif
+ #ifdef CONFIG_SLOW_WORK
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "slow-work",
+ .mode = 0555,
+ .child = slow_work_sysctls,
+ },
+ #endif
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
.data = &dirty_expire_interval,
.maxlen = sizeof(dirty_expire_interval),
.mode = 0644,
- .proc_handler = &proc_dointvec_userhz_jiffies,
+ .proc_handler = &proc_dointvec,
},
{
.ctl_name = VM_NR_PDFLUSH_THREADS,
.data = &lease_break_time,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &zero,
- .extra2 = &two,
+ .proc_handler = &proc_dointvec,
},
#endif
#ifdef CONFIG_AIO
.data = &suid_dumpable,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ .extra2 = &two,
},
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
{
range 0 1
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
+
+config DETECT_HUNG_TASK
+ bool "Detect Hung Tasks"
+ depends on DEBUG_KERNEL
+ default DETECT_SOFTLOCKUP
+ help
+ Say Y here to enable the kernel to detect "hung tasks",
+ which are bugs that cause the task to be stuck in
+ uninterruptible "D" state indefinitiley.
+
+ When a hung task is detected, the kernel will print the
+ current stack trace (which you should report), but the
+ task will stay in uninterruptible state. If lockdep is
+ enabled then all held locks will also be reported. This
+ feature has negligible overhead.
+
+config BOOTPARAM_HUNG_TASK_PANIC
+ bool "Panic (Reboot) On Hung Tasks"
+ depends on DETECT_HUNG_TASK
+ help
+ Say Y here to enable the kernel to panic on "hung tasks",
+ which are bugs that cause the kernel to leave a task stuck
+ in uninterruptible "D" state.
+
+ The panic can be used in combination with panic_timeout,
+ to cause the system to reboot automatically after a
+ hung task has been detected. This feature is useful for
+ high-availability systems that have uptime guarantees and
+ where a hung tasks must be resolved ASAP.
+
+ Say N if unsure.
+
+config BOOTPARAM_HUNG_TASK_PANIC_VALUE
+ int
+ depends on DETECT_HUNG_TASK
+ range 0 1
+ default 0 if !BOOTPARAM_HUNG_TASK_PANIC
+ default 1 if BOOTPARAM_HUNG_TASK_PANIC
config SCHED_DEBUG
bool "Collect scheduler debugging info"
bool
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
select STACKTRACE
- select FRAME_POINTER if !X86 && !MIPS && !PPC
+ select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND
select KALLSYMS
select KALLSYMS_ALL
to properly maintain and use. This enables checks that help
you to keep things correct.
+ source mm/Kconfig.debug
source kernel/trace/Kconfig
config PROVIDE_OHCI1394_DMA_INIT
If unsure, say N.
- menuconfig BUILD_DOCSRC
+ config BUILD_DOCSRC
bool "Build targets in Documentation/ tree"
depends on HEADERS_CHECK
help
Say N if you are unsure.
- config DYNAMIC_PRINTK_DEBUG
- bool "Enable dynamic printk() call support"
+ config DYNAMIC_DEBUG
+ bool "Enable dynamic printk() support"
default n
depends on PRINTK
+ depends on DEBUG_FS
select PRINTK_DEBUG
help
Compiles debug level messages into the kernel, which would not
otherwise be available at runtime. These messages can then be
- enabled/disabled on a per module basis. This mechanism implicitly
- enables all pr_debug() and dev_dbg() calls. The impact of this
- compile option is a larger kernel text size of about 2%.
+ enabled/disabled based on various levels of scope - per source file,
+ function, module, format string, and line number. This mechanism
+ implicitly enables all pr_debug() and dev_dbg() calls. The impact of
+ this compile option is a larger kernel text size of about 2%.
Usage:
- Dynamic debugging is controlled by the debugfs file,
- dynamic_printk/modules. This file contains a list of the modules that
- can be enabled. The format of the file is the module name, followed
- by a set of flags that can be enabled. The first flag is always the
- 'enabled' flag. For example:
+ Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file,
+ which is contained in the 'debugfs' filesystem. Thus, the debugfs
+ filesystem must first be mounted before making use of this feature.
+ We refer the control file as: <debugfs>/dynamic_debug/ddebug. This
+ file contains a list of the debug statements that can be enabled. The
+ format for each line of the file is:
- <module_name> <enabled=0/1>
- .
- .
- .
+ filename:lineno [module]function flags format
- <module_name> : Name of the module in which the debug call resides
- <enabled=0/1> : whether the messages are enabled or not
+ filename : source file of the debug statement
+ lineno : line number of the debug statement
+ module : module that contains the debug statement
+ function : function that contains the debug statement
+ flags : 'p' means the line is turned 'on' for printing
+ format : the format used for the debug statement
From a live system:
- snd_hda_intel enabled=0
- fixup enabled=0
- driver enabled=0
+ nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
+ # filename:lineno [module]function flags format
+ fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
+ fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
+ fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
- Enable a module:
+ Example usage:
- $echo "set enabled=1 <module_name>" > dynamic_printk/modules
+ // enable the message at line 1603 of file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
+ <debugfs>/dynamic_debug/ddebug
- Disable a module:
+ // enable all the messages in file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=0 <module_name>" > dynamic_printk/modules
+ // enable all the messages in the NFS server module
+ nullarbor:~ # echo -n 'module nfsd +p' >
+ <debugfs>/dynamic_debug/ddebug
- Enable all modules:
+ // enable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=1 all" > dynamic_printk/modules
+ // disable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process -p' >
+ <debugfs>/dynamic_debug/ddebug
- Disable all modules:
+ See Documentation/dynamic-debug-howto.txt for additional information.
- $echo "set enabled=0 all" > dynamic_printk/modules
-
- Finally, passing "dynamic_printk" at the command line enables
- debugging for all modules. This mode can be turned off via the above
- disable command.
+ config DMA_API_DEBUG
+ bool "Enable debugging of DMA-API usage"
+ depends on HAVE_DMA_API_DEBUG
+ help
+ Enable this option to debug the use of the DMA API by device drivers.
+ With this option you will be able to detect common bugs in device
+ drivers like double-freeing of DMA mappings or freeing mappings that
+ were never allocated.
+ This option causes a performance degredation. Use only if you want
+ to debug device drivers. If unsure, say N.
source "samples/Kconfig"
git.openpandora.org / pandora-kernel.git / commitdiff