search for: rlock

Hi, Here is a question about starting of subsequent VMs. In the function of "start" from the class of XendDomain which is in the module of xen.xend.XendDomain, there's a pair of operations acquiring and releasing threading.RLock, which is like following: def domain_start(self, domid, start_paused = True): self.domains_lock.acquire() .... self.domains_lock.release() The confine of the locked area is quite large, in fact it covers nearly all the function, which would cause most time in the se...

...[1] ====================================================== [ INFO: possible circular locking dependency detected ] 3.10.0-0+tip-xeon+lockdep #0+tip Not tainted ------------------------------------------------------- swapper/7/0 is trying to acquire lock: (&(&dev->vblank_time_lock)->rlock){-.....}, at: [<ffffffffa0086269>] drm_handle_vblank+0x69/0x400 [drm] but task is already holding lock: (&(&event->lock)->rlock){-.....}, at: [<ffffffffa0101dbd>] nouveau_event_trigger+0x4d/0xd0 [nouveau] which lock already depends on the new lock. the existing depende...

...6642] [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] [ 2417.746644] 2.6.35-rc4-nv+ #379 [ 2417.746645] ------------------------------------------------------ [ 2417.746648] warsow/2850 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 2417.746650] (&(&mm->unused_lock)->rlock){+.+...}, at: [<ffffffff8129f0c0>] drm_mm_put_block+0x17a/0x1c0 [ 2417.746657] [ 2417.746658] and this task is already holding: [ 2417.746659] (&(&dev_priv->context_switch_lock)->rlock){-.....}, at: [<ffffffffa00ac502>] nouveau_channel_free+0x10f/0x233 [nouveau] [ 2417.7...

...-safe -> HARDIRQ-unsafe lock order detected ] > [ 123.551253] 2.6.35-rc6-mmotm0727 #1 > [ 123.551253] ------------------------------------------------------ > [ 123.551253] e16/3822 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: > [ 123.551253] (&(&mm->unused_lock)->rlock){+.+...}, at: [<ffffffff812a94bc>] drm_mm_put_block+0x10e/0x142 > [ 123.551253] > [ 123.551253] and this task is already holding: > [ 123.551253] (&(&dev_priv->context_switch_lock)->rlock){-.....}, at: [<ffffffff812bdbab>] nouveau_channel_free+0x10f/0x233 &gt...

...662]: /dev/mapper/fedora--foo1-root: clean, 22215/486720 files, 222526/1944576 blocks BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 2 locks held by swapper/1/0: #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] virtblk_done+0x42/0xe0 [virtio_blk] #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 irq event stamp: 33518 hardirqs last enabled at (33515): [<ffffffff8102544f>] default_idle+0...

...662]: /dev/mapper/fedora--foo1-root: clean, 22215/486720 files, 222526/1944576 blocks BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 2 locks held by swapper/1/0: #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] virtblk_done+0x42/0xe0 [virtio_blk] #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 irq event stamp: 33518 hardirqs last enabled at (33515): [<ffffffff8102544f>] default_idle+0...

...8.327235] ============================================= [ 1998.329940] [ INFO: possible recursive locking detected ] [ 1998.329940] 2.6.39+ #3 [ 1998.329940] --------------------------------------------- [ 1998.329940] dd/25718 is trying to acquire lock: [ 1998.329940] (&(&eb->lock)->rlock){+.+...}, at: [<ffffffffa025dbe1>] btrfs_try_spin_lock+0x2a/0x89 [btrfs] [ 1998.329940] [ 1998.329940] but task is already holding lock: [ 1998.329940] (&(&eb->lock)->rlock){+.+...}, at: [<ffffffffa025dbae>] btrfs_clear_lock_blocking+0x22/0x2b [btrfs] [ 1998.478275] [ 1...

...-root: clean, 22215/486720 > files, 222526/1944576 blocks > BUG: sleeping function called from invalid context at > kernel/locking/mutex.c:586 > in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 > 2 locks held by swapper/1/0: > #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] > virtblk_done+0x42/0xe0 [virtio_blk] > #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: > [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 > irq event stamp: 33518 > hardirqs last enabled at (33515): [<ffffffff810...

...[ INFO: possible circular locking dependency detected ] > [ 326.168496] 3.13.6 #1270 Not tainted > [ 326.168500] ------------------------------------------------------- > [ 326.168504] ldconfig/22297 is trying to acquire lock: > [ 326.168507] (&(&priv->fan->lock)->rlock){-.-...}, at: [<ffffffffa00d5363>] nouveau_fan_update+0xeb/0x252 [nouveau] > [ 326.168551] > but task is already holding lock: > [ 326.168555] (&(&priv->sensor.alarm_program_lock)->rlock){-.-...}, at: [<ffffffffa00d6a8a>] alarm_timer_callback+0xf1/0x179 [nouvea...

...invalid context bug triggerd by md invoking sysfs_notify() from IO completion path. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 2 locks held by swapper/1/0: #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] virtblk_done+0x42/0xe0 [virtio_blk] #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 irq event stamp: 33518 hardirqs last enabled at (33515): [<ffffffff8102544f>] default_idle+0...

...invalid context bug triggerd by md invoking sysfs_notify() from IO completion path. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 2 locks held by swapper/1/0: #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] virtblk_done+0x42/0xe0 [virtio_blk] #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 irq event stamp: 33518 hardirqs last enabled at (33515): [<ffffffff8102544f>] default_idle+0...

When user hot-unplug a disk which is busy serving I/O, __blk_run_queue might be unable to drain all the requests. As a result, the blk_drain_queue() would loop forever and blk_cleanup_queue would not return. So hot-unplug will fail. This patch adds a callback in blk_drain_queue() for low lever driver to abort requests. Currently, this is useful for virtio-blk to do cleanup in hot-unplug. Cc:

When user hot-unplug a disk which is busy serving I/O, __blk_run_queue might be unable to drain all the requests. As a result, the blk_drain_queue() would loop forever and blk_cleanup_queue would not return. So hot-unplug will fail. This patch adds a callback in blk_drain_queue() for low lever driver to abort requests. Currently, this is useful for virtio-blk to do cleanup in hot-unplug. Cc:

...spinlock, when the processes wake up, they would release the block provided spinlock. ===================================== [ BUG: bad unlock balance detected! ] 3.4.0-rc7+ #238 Not tainted ------------------------------------- fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at: [<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380 but there are no more locks to release! other info that might help us debug this: 1 lock held by fio/3587: #0: (&(&vblk->lock)->rlock){......}, at: [<ffffffff8132661a>] get_request_wait+0x19a/0x250 Other drivers use b...

...spinlock, when the processes wake up, they would release the block provided spinlock. ===================================== [ BUG: bad unlock balance detected! ] 3.4.0-rc7+ #238 Not tainted ------------------------------------- fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at: [<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380 but there are no more locks to release! other info that might help us debug this: 1 lock held by fio/3587: #0: (&(&vblk->lock)->rlock){......}, at: [<ffffffff8132661a>] get_request_wait+0x19a/0x250 Other drivers use b...

...by md invoking > sysfs_notify() from IO completion path. > > BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 > in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 > 2 locks held by swapper/1/0: > #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [<ffffffffa0039042>] virtblk_done+0x42/0xe0 [virtio_blk] > #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [<ffffffff81633718>] bitmap_endwrite+0x68/0x240 > irq event stamp: 33518 > hardirqs last enabled at (33515): [<ffffffff8102544f>]...

...e.c:949) [ 37.712372] #1: ffff8880b32e00a8 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock (linux/drivers/gpu/drm/drm_modeset_lock.c:258 linux/drivers/gpu/drm/drm_modeset_lock.c:342 linux/drivers/gpu/drm/drm_modeset_lock.c:338) [ 37.713415] #2: ffff8880b32eb6c0 (&(&vgvq->qlock)->rlock){+.+.}, at: virtio_gpu_queue_fenced_ctrl_buffer (linux/drivers/gpu/drm/virtio/virtgpu_vq.c:381) [ 37.714650] [ 37.714650] stack backtrace: [ 37.715140] CPU: 0 PID: 1869 Comm: Xorg Not tainted 5.5.0-rc5+ #605 [ 37.715889] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 0...

Hi, We have couple of places which can result in deadlock. This patch series fixes these. We can be called with fc->bg_lock (for background requests) while submitting a request. This leads to two constraints. - We can't end requests in submitter's context and call fuse_end_request() as it tries to take fc->bg_lock as well. So queue these requests on a list and use a worker to

On 06/29/2014 02:47 PM, Michael S. Tsirkin wrote: > On Sun, Jun 29, 2014 at 09:32:22PM +0200, Christoph Hellwig wrote: >> On Sun, Jun 29, 2014 at 11:26:37AM +0300, Michael S. Tsirkin wrote: >>> On Fri, Jun 27, 2014 at 07:57:38AM -0400, Josh Boyer wrote: >>>> Hi All, >>>> >>>> We've had a report[1] of the virt_blk driver causing a lot of

On 06/29/2014 02:47 PM, Michael S. Tsirkin wrote: > On Sun, Jun 29, 2014 at 09:32:22PM +0200, Christoph Hellwig wrote: >> On Sun, Jun 29, 2014 at 11:26:37AM +0300, Michael S. Tsirkin wrote: >>> On Fri, Jun 27, 2014 at 07:57:38AM -0400, Josh Boyer wrote: >>>> Hi All, >>>> >>>> We've had a report[1] of the virt_blk driver causing a lot of