Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Don Zickus bde92cf455 kernel/watchdog.c: remove preemption restrictions when restarting lockup detector ... Peter Wu noticed the following splat on his machine when updating /proc/sys/kernel/watchdog_thresh: BUG: sleeping function called from invalid context at mm/slub.c:965 in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: init 3 locks held by init/1: #0: (sb_writers#3){.+.+.+}, at: [<ffffffff8117b663>] vfs_write+0x143/0x180 #1: (watchdog_proc_mutex){+.+.+.}, at: [<ffffffff810e02d3>] proc_dowatchdog+0x33/0x110 #2: (cpu_hotplug.lock){.+.+.+}, at: [<ffffffff810589c2>] get_online_cpus+0x32/0x80 Preemption disabled at:[<ffffffff810e0384>] proc_dowatchdog+0xe4/0x110 CPU: 0 PID: 1 Comm: init Not tainted 3.16.0-rc1-testing #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x4e/0x7a __might_sleep+0x11d/0x190 kmem_cache_alloc_trace+0x4e/0x1e0 perf_event_alloc+0x55/0x440 perf_event_create_kernel_counter+0x26/0xe0 watchdog_nmi_enable+0x75/0x140 update_timers_all_cpus+0x53/0xa0 proc_dowatchdog+0xe4/0x110 proc_sys_call_handler+0xb3/0xc0 proc_sys_write+0x14/0x20 vfs_write+0xad/0x180 SyS_write+0x49/0xb0 system_call_fastpath+0x16/0x1b NMI watchdog: disabled (cpu0): hardware events not enabled What happened is after updating the watchdog_thresh, the lockup detector is restarted to utilize the new value. Part of this process involved disabling preemption. Once preemption was disabled, perf tried to allocate a new event (as part of the restart). This caused the above BUG_ON as you can't sleep with preemption disabled. The preemption restriction seemed agressive as we are not doing anything on that particular cpu, but with all the online cpus (which are protected by the get_online_cpus lock). Remove the restriction and the BUG_ON goes away. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reported-by: Peter Wu <peter@lekensteyn.nl> Tested-by: Peter Wu <peter@lekensteyn.nl> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [3.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-06-23 16:47:43 -07:00
..
debug	kernel/printk: use symbolic defines for console loglevels	2014-06-04 16:54:17 -07:00
events	Merge branch 'perf/core' into perf/urgent, to pick up the latest fixes	2014-06-14 14:10:08 +02:00
gcov	gcov: add support for GCC 4.9	2014-06-10 15:34:46 -07:00
irq	genirq: Improve documentation to match current implementation	2014-05-27 10:16:44 +02:00
locking	Merge branch 'locking-urgent-for-linus.patch' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-06-21 07:06:02 -10:00
power	x86, kaslr: boot-time selectable with hibernation	2014-06-16 23:30:44 +02:00
printk	kernel/printk: use symbolic defines for console loglevels	2014-06-04 16:54:17 -07:00
rcu	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next	2014-06-03 12:57:53 -07:00
sched	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-06-12 19:42:15 -07:00
time	Merge branch 'akpm' (patchbomb from Andrew) into next	2014-06-04 16:55:13 -07:00
trace	One bug fix that goes back to 3.10. Accessing a non existent buffer	2014-06-12 21:07:25 -07:00
.gitignore
acct.c	ipc, kernel: clear whitespace	2014-06-06 16:08:14 -07:00
async.c
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-06-12 14:27:40 -07:00
audit.h
audit_tree.c
audit_watch.c
auditfilter.c	Merge git://git.infradead.org/users/eparis/audit	2014-04-12 12:38:53 -07:00
auditsc.c	auditsc: audit_krule mask accesses need bounds checking	2014-06-10 08:44:40 -07:00
backtracetest.c	kernel/backtracetest.c: replace no level printk by pr_info()	2014-06-04 16:54:14 -07:00
bounds.c
capability.c	fs,userns: Change inode_capable to capable_wrt_inode_uidgid	2014-06-10 13:57:22 -07:00
cgroup.c	Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-06-09 15:03:33 -07:00
cgroup_freezer.c	cgroup: remove css_parent()	2014-05-16 13:22:48 -04:00
compat.c	kernel/compat.c: use sizeof() instead of sizeof	2014-06-04 16:54:19 -07:00
configs.c
context_tracking.c	x86/kprobes: Fix build errors and blacklist context_track_user	2014-06-14 09:07:44 +02:00
cpu.c	More ACPI and power management updates for 3.16-rc1	2014-06-12 13:14:19 -07:00
cpu_pm.c
cpuset.c	Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-06-09 15:03:33 -07:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c	kernel/exec_domain.c: code clean-up	2014-06-04 16:54:15 -07:00
exit.c	signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch]	2014-06-06 16:08:11 -07:00
extable.c
fork.c	ptrace: fix fork event messages across pid namespaces	2014-06-06 16:08:11 -07:00
freezer.c
futex.c	Merge branch 'next' (accumulated 3.16 merge window patches) into master	2014-06-08 11:31:16 -07:00
futex_compat.c
groups.c
hrtimer.c	Merge branch 'perf/urgent' into perf/core, to resolve conflict and to prepare for new patches	2014-06-06 07:55:06 +02:00
hung_task.c	kernel/hung_task.c: convert simple_strtoul to kstrtouint	2014-06-04 16:54:15 -07:00
irq_work.c
itimer.c
jump_label.c
kallsyms.c	kernel: use macros from compiler.h instead of __attribute__((...))	2014-04-07 16:36:11 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks	2014-06-06 07:58:28 +02:00
Kconfig.preempt
kexec.c	kexec: save PG_head_mask in VMCOREINFO	2014-06-23 16:47:43 -07:00
kmod.c	signals: change wait_for_helper() to use kernel_sigaction()	2014-06-06 16:08:12 -07:00
kprobes.c	kprobes: Show blacklist entries via debugfs	2014-04-24 10:26:41 +02:00
ksysfs.c	kobject: Make support for uevent_helper optional.	2014-04-25 12:00:49 -07:00
kthread.c	kthread: fix return value of kthread_create() upon SIGKILL.	2014-06-04 16:53:51 -07:00
latencytop.c	kernel/latencytop.c: convert seq_printf to seq_puts	2014-06-04 16:54:15 -07:00
Makefile
module-internal.h
module.c	Most of this is cleaning up various driver sysfs permissions so we can	2014-06-11 16:09:14 -07:00
module_signing.c
notifier.c	kprobes, notifier: Use NOKPROBE_SYMBOL macro in notifier	2014-04-24 10:26:39 +02:00
nsproxy.c
padata.c
panic.c	kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers	2014-06-06 16:08:12 -07:00
params.c	param: hand arguments after -- straight to init	2014-04-28 11:48:34 +09:30
pid.c
pid_namespace.c
posix-cpu-timers.c
posix-timers.c
profile.c	kernel/profile.c: use static const char instead of static char	2014-06-06 16:08:13 -07:00
ptrace.c
range.c
reboot.c	kernel/reboot.c: convert simple_strtoul to kstrtoint	2014-06-04 16:54:15 -07:00
relay.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-04-12 14:49:50 -07:00
res_counter.c	kernel/res_counter.c: replace simple_strtoull by kstrtoull	2014-06-04 16:54:15 -07:00
resource.c	resources: Clarify sanity check message	2014-05-23 10:47:21 -06:00
seccomp.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-06-12 14:27:40 -07:00
signal.c	signals: introduce kernel_sigaction()	2014-06-06 16:08:12 -07:00
smp.c	CPU hotplug, smp: flush any pending IPI callbacks before CPU offline	2014-06-23 16:47:43 -07:00
smpboot.c
smpboot.h
softirq.c	Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu	2014-05-22 11:36:10 +02:00
stacktrace.c
stop_machine.c	kernel/stop_machine.c: kernel-doc warning fix	2014-06-04 16:54:15 -07:00
sys.c	sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()	2014-05-22 11:16:36 +02:00
sys_ni.c	sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL	2014-06-04 16:54:14 -07:00
sysctl.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next	2014-06-19 07:50:07 -10:00
sysctl_binary.c
system_certificates.S
system_keyring.c
task_work.c
taskstats.c
test_kprobes.c
time.c
timeconst.bc
timer.c	timer: Prevent overflow in apply_slack	2014-04-30 13:46:17 +02:00
torture.c	torture: Remove __init from torture_init_begin/end	2014-05-14 09:46:30 -07:00
tracepoint.c	kernel/tracepoint.c: kernel-doc fixes	2014-06-04 16:54:15 -07:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c	kernel/user.c: drop unused field 'files' from user_struct	2014-06-04 16:54:16 -07:00
user_namespace.c	kernel/user_namespace.c: kernel-doc/checkpatch fixes	2014-06-06 16:08:13 -07:00
utsname.c
utsname_sysctl.c	sysctl: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
watchdog.c	kernel/watchdog.c: remove preemption restrictions when restarting lockup detector	2014-06-23 16:47:43 -07:00
workqueue.c	Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2014-06-09 14:56:49 -07:00
workqueue_internal.h	workqueue: rename manager_mutex to attach_mutex	2014-05-20 10:59:32 -04:00