tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.
The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
m_cache_alloc_trace+0x92/0x1c0
drm_atomic_helper_setup_commit+0x285/0x2f0 [drm_kms_helper]
intel_atomic_commit+0x35/0x4f0 [i915]
drm_atomic_commit+0x46/0x50 [drm]
drm_mode_atomic_ioctl+0x7d4/0xab0 [drm]
drm_ioctl+0x2b3/0x490 [drm]
do_vfs_ioctl+0x69c/0x700
SyS_ioctl+0x4e/0x80
entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Freed in drm_event_cancel_free+0xa3/0xb0 [drm] age=0 cpu=3 pid=1529
__slab_free+0x48/0x2e0
kfree+0x159/0x1a0
drm_event_cancel_free+0xa3/0xb0 [drm]
drm_mode_atomic_ioctl+0x86d/0xab0 [drm]
drm_ioctl+0x2b3/0x490 [drm]
do_vfs_ioctl+0x69c/0x700
SyS_ioctl+0x4e/0x80
entry_SYSCALL_64_fastpath+0x13/0x94
INFO: Slab 0xffffde1f0997b080 objects=17 used=2 fp=0xffff92fb65ec2578 flags=0x200000000008101
INFO: Object 0xffff92fb65ec2578 @offset=1400 fp=0xffff92fb65ec2ae8
Redzone ffff92fb65ec2570: bb bb bb bb bb bb bb bb ........
Object ffff92fb65ec2578: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec2588: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec2598: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25a8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff92fb65ec25e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
Redzone ffff92fb65ec25f8: bb bb bb bb bb bb bb bb ........
Padding ffff92fb65ec2738: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
CPU: 3 PID: 180 Comm: kworker/3:2 Tainted: G BU 4.10.0-rc6-patser+ #5039
Hardware name: /NUC5PPYB, BIOS PYBSWCEL.86A.0031.2015.0601.1712 06/01/2015
Workqueue: events intel_atomic_helper_free_state [i915]
Call Trace:
dump_stack+0x4d/0x6d
print_trailer+0x20c/0x220
free_debug_processing+0x1c6/0x330
? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
__slab_free+0x48/0x2e0
? drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
kfree+0x159/0x1a0
drm_atomic_state_default_clear+0xf7/0x1c0 [drm]
? drm_atomic_state_clear+0x30/0x30 [drm]
intel_atomic_state_clear+0xd/0x20 [i915]
drm_atomic_state_clear+0x1a/0x30 [drm]
__drm_atomic_state_free+0x13/0x60 [drm]
intel_atomic_helper_free_state+0x5d/0x70 [i915]
process_one_work+0x260/0x4a0
worker_thread+0x2d1/0x4f0
kthread+0x127/0x130
? process_one_work+0x4a0/0x4a0
? kthread_stop+0x120/0x120
ret_from_fork+0x29/0x40
FIX kmalloc-128: Object at 0xffff92fb65ec2578 not freed
Fixes: 3b24f7d67581 ("drm/atomic: Add struct drm_crtc_commit to track async updates")
Fixes: 9626014258a5 ("drm/fence: add in-fences support")
Cc: <stable@vger.kernel.org> # v4.8+
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1485854725-27640-1-git-send-email-maarten.lankhorst@linux.intel.com
