Tejun Heo
cd42d559e4
kthread: implement probe_kthread_data() ...
One of the problems that arise when converting dedicated custom threadpool
to workqueue is that the shared worker pool used by workqueue anonimizes
each worker making it more difficult to identify what the worker was doing
on which target from the output of sysrq-t or debug dump from oops, BUG()
and friends.
For example, after writeback is converted to use workqueue instead of
priviate thread pool, there's no easy to tell which backing device a
writeback work item was working on at the time of task dump, which,
according to our writeback brethren, is important in tracking down issues
with a lot of mounted file systems on a lot of different devices.
This patchset implements a way for a work function to mark its execution
instance so that task dump of the worker task includes information to
indicate what the work item was doing.
An example WARN dump would look like the following.
WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0()
Modules linked in:
CPU: 0 Pid: 28 Comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ #24
Hardware name: empty empty/S3992, BIOS 080011 10/26/2007
Workqueue: writeback bdi_writeback_workfn (flush-8:16)
ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8
ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0
ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08
Call Trace:
[<ffffffff81c61855>] dump_stack+0x19/0x1b
[<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
...
This patch:
Implement probe_kthread_data() which returns kthread_data if accessible.
The function is equivalent to kthread_data() except that the specified
@task may not be a kthread or its vfork_done is already cleared rendering
struct kthread inaccessible. In the former case, probe_kthread_data() may
return any value. In the latter, NULL.
This will be used to safely print debug information without affecting
synchronization in the normal paths. Workqueue debug info printing on
dump_stack() and friends will make use of it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 08:15:40 -07:00
KGDB/KDB fixes and cleanups
2013-03-02 08:31:39 -08:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:41:01 -07:00
kernel/gcov: remove depends on CONFIG_EXPERIMENTAL
2013-01-11 11:39:33 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
Driver core patches for 3.9-rc1
2013-02-21 12:05:51 -08:00
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:50:17 -07:00
clockevents: Set dummy handler on CPU_DEAD shutdown
2013-04-25 13:57:04 +02:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:41:01 -07:00
kernel/hz.bc: ignore.
2013-04-22 07:09:06 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
async: rename and redefine async_func_ptr
2013-03-12 13:59:14 -07:00
audit: don't check if kauditd is valid every time
2013-04-29 15:54:26 -07:00
audit: remove unnecessary #if CONFIG_AUDIT
2013-04-29 15:54:26 -07:00
kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees()
2013-04-29 15:54:26 -07:00
audit: catch possible NULL audit buffers
2013-01-11 14:54:55 -08:00
kernel/auditfilter.c: tree and watch will memory leak when failure occurs
2013-04-29 15:54:26 -07:00
kernel/auditsc.c: use kzalloc instead of kmalloc+memset
2013-04-29 15:54:26 -07:00
Add file_ns_capable() helper function for open-time capability checking
2013-04-14 10:06:31 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:43:28 -07:00
cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()
2012-11-19 08:13:38 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
2013-02-23 18:50:11 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 18:19:48 -08:00
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 19:04:55 -08:00
kernel/cpu_pm.c: fix various typos
2012-05-31 17:49:27 -07:00
Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2013-04-29 19:14:20 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2012-12-18 10:55:28 -08:00
cputime: Use accessors to read task cputime stats
2013-01-27 19:23:31 +01:00
Revert "lockdep: check that no locks held at freeze time"
2013-03-31 11:38:33 -07:00
extable: Flip the sorting message
2013-04-15 13:25:16 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:43:28 -07:00
freezer: change ptrace_stop/do_signal_stop to use freezable_schedule()
2012-10-26 14:27:49 -07:00
futex: fix kernel-doc notation and spello
2013-03-12 20:42:10 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
2013-02-23 18:50:11 -08:00
Merge branch 'linus' into timers/core
2013-04-24 20:33:54 +02:00
Merge branch 'nohz/printk-v8' into irq/core
2013-02-05 00:48:46 +01:00
jump_label: Export jump_label_rate_limit()
2012-08-06 19:00:35 +03:00
vsprintf: fix %ps on non symbols when using kallsyms
2012-05-29 16:22:32 -07:00
kcmp: include linux/ptrace.h
2012-12-20 17:40:19 -08:00
locking: Adjust spin lock inlining Kconfig options
2012-09-13 17:56:13 +02:00
kexec, vmalloc: export additional vmalloc layer information
2013-04-29 15:54:34 -07:00
Merge branch 'master' into for-3.9-async
2013-01-23 09:31:01 -08:00
kprobes: Fix a double lock bug of kprobe_mutex
2013-04-18 08:58:38 -07:00
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-12-11 18:10:49 -08:00
kthread: implement probe_kthread_data()
2013-04-30 17:04:02 -07:00
brlocks/lglocks: turn into functions
2012-05-29 23:28:41 -04:00
lockdep: Consolidate bug messages into a single print_lockdep_off() function
2013-04-26 08:37:22 +02:00
lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name()
2012-10-24 12:39:09 +02:00
idle: Provide a generic entry point for the idle code
2013-04-08 17:39:23 +02:00
MODSIGN: Avoid using .incbin in C source
2012-12-14 13:06:44 +10:30
keys: use keyring_alloc() to create module signing keyring
2012-12-20 17:40:21 -08:00
MODSIGN: Move the magic string to the end of a module and eliminate the search
2012-10-19 17:30:40 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
MODSIGN: Don't use enum-type bitfields in module signature info block
2012-12-05 11:27:24 +10:30
mutex: Back out architecture specific check for negative mutex count
2013-04-19 09:33:36 +02:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
padata: use __this_cpu_read per-cpu helper
2012-12-06 17:16:23 +08:00
dump_stack: implement arch-specific hardware description in task dumps
2013-04-30 17:04:02 -07:00
params: replace printk(KERN_<LVL>...) with pr_<lvl>(...)
2012-05-04 17:28:18 -07:00
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
pid: Handle the exit of a multi-threaded init.
2013-03-26 03:41:23 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 19:05:45 -08:00
posix-timers: Remove unused variable
2013-04-18 12:51:19 +02:00
dump_stack: unify debug information printed by show_regs()
2013-04-30 17:04:02 -07:00
profiling: Remove unused timer hook
2013-01-24 15:37:26 +01:00
uprobes: Add exports for module use
2013-02-08 17:47:13 +01:00
kernel/range.c: subtract_range: fix the broken phrase issued by printk
2013-04-30 17:04:01 -07:00
rcu: Provide RCU CPU stall warnings for tiny RCU
2013-01-28 22:06:21 -08:00
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
rcu: Provide RCU CPU stall warnings for tiny RCU
2013-01-28 22:06:21 -08:00
rcu: Allow rcutorture to be built at low optimization levels
2013-02-04 12:18:20 -08:00
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-04-30 07:39:01 -07:00
Merge branches 'doc.2013.03.12a', 'fixes.2013.03.13a' and 'idlenocb.2013.03.26b' into HEAD
2013-03-26 08:07:38 -07:00
Merge branches 'doc.2013.03.12a', 'fixes.2013.03.13a' and 'idlenocb.2013.03.26b' into HEAD
2013-03-26 08:07:38 -07:00
rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks
2013-03-26 08:04:51 -07:00
new helper: file_inode(file)
2013-02-22 23:31:31 -05:00
res_counter: return amount of charges after res_counter_uncharge()
2012-12-18 15:02:12 -08:00
mem hotunplug: fix kfree() of bootmem memory
2013-04-29 15:54:40 -07:00
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
locking/rtmutex/tester: Set correct permissions on sysfs files
2013-04-10 14:48:37 +02:00
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
lockdep, rwsem: provide down_write_nest_lock()
2013-01-11 14:54:55 -08:00
seccomp: Make syscall skipping and nr changes more consistent
2012-10-02 21:14:29 +10:00
arc, print-fatal-signals: reduce duplicated information
2013-04-30 17:04:02 -07:00
smp: make smp_call_function_many() use logic similar to smp_call_function_single()
2013-02-21 17:22:20 -08:00
kthread: Prevent unpark race which puts threads on the wrong cpu
2013-04-12 14:18:43 +02:00
smpboot: Provide infrastructure for percpu hotplug threads
2012-08-13 17:01:07 +02:00
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-03-05 18:10:04 -08:00
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
2013-02-07 15:19:36 -08:00
stop_machine: Mark per cpu stopper enabled early
2013-02-26 22:25:17 +01:00
PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()
2013-04-08 22:10:40 +02:00
module: add syscall to load module from fd
2012-12-14 13:05:22 +10:30
mm: replace hardcoded 3% with admin_reserve_pages knob
2013-04-29 15:54:36 -07:00
sysctl: fix null checking in bin_dn_node_address()
2013-02-27 19:10:21 -08:00
task_work: task_work_add() should not succeed after exit_task_work()
2012-09-13 16:47:34 +02:00
taskstats: cgroupstats_user_cmd() may leak on error
2012-10-06 03:05:31 +09:00
kernel/: rename random32() to prandom_u32()
2013-04-29 18:28:42 -07:00
timekeeping: Use inject_offset in warp_clock
2013-03-15 16:50:20 -07:00
kernel: Replace timeconst.pl with a bc script
2013-02-16 23:17:25 +01:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 18:19:48 -08:00
Tracing updates for Linux 3.10
2013-04-29 13:55:38 -07:00
cputime: Use accessors to read task cputime stats
2013-01-27 19:23:31 +01:00
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
userns: Restrict when proc and sysfs can be mounted
2013-03-27 07:50:08 -07:00
userns: Changing any namespace id mappings should require privileges
2013-04-14 18:11:32 -07:00
kernel/utsname.c: fix wrong comment about clone_uts_ns()
2013-02-27 19:10:22 -08:00
kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block
2013-02-27 19:10:22 -08:00
propagate name change to comments in kernel source
2012-12-06 10:39:54 +01:00
watchdog: Add comments to explain the watchdog_disabled variable
2013-03-14 08:24:05 +01:00
workqueue: use kmem_cache_free() instead of kfree()
2013-04-09 11:33:40 -07:00
workqueue: directly restore CPU affinity of workers from CPU_ONLINE
2013-03-19 13:45:21 -07:00
cd42d559e4