Attachment 127144 Details for Bug 97880 – log 1

log 1

log_1 (text/plain), 6.37 KB, created by Mihail Konev on 2016-10-08 21:22:17 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Mihail Konev

Created: 2016-10-08 21:22:17 UTC

Size: 6.37 KB

patch

obsolete

>
>There Xserver starts.
>
><..>
>[  3287.050] (II) config/udev: ignoring device /dev/tty7 without property ID_INPUT set
>[  3287.050] (II) config/udev: ignoring device /dev/tty8 without property ID_INPUT set
>[  3287.050] (II) config/udev: ignoring device /dev/tty9 without property ID_INPUT set
>
>Now it finished detecting devices.
>
>Input thread tries to acquire the lock.
>
>[  3287.054] (II) inputh lock ...
>[  3287.054] (II) inputh locked
>
>Input thread sees the attachments.
>
>[  3287.054] (II) dev fd=19 state=0 
>[  3287.054] (II) dev fd=20 state=0 
>[  3287.054] (II) dev fd=21 state=0 
>[  3287.054] (II) dev fd=22 state=0 
>[  3287.054] (II) dev fd=23 state=0 
>[  3287.054] (II) dev fd=24 state=0 
>
>There are 6 devices total.
>
>
>User does Ctrl-Alt-F1
>Xserver (main thread in hw/xfree86/common/xf86Events.c, in xf86DisableDevicesForVTSwitch)
>for each device calls InputThreadUnregisterDev, which really just sets dev->state
>(under an input_lock), so that input thread sees that and does the proper detach.
>
>[  3291.194] (II) InputThreadUnregisterDev(fd=19) ... 
>[  3291.194] (II) InputThreadUnregisterDev: found a device: fd=19 state=1 
>
>For first device, input thread sees the dev->state change.
>It tries to acquire the lock.
>
>[  3291.194] (II) inputh lock ...
>[  3291.208] (II) inputh locked
>
>With lock held, input thread detaches the device.
>
>[  3291.208] (II) dev fd=19 state=2 
>
>The same goes for device 2.
>
>[  3291.208] (II) InputThreadUnregisterDev(fd=20) ... 
>[  3291.208] (II) InputThreadUnregisterDev: found a device: fd=20 state=1 
>[  3291.208] (II) inputh lock ...
>[  3291.220] (II) inputh locked
>[  3291.220] (II) dev fd=20 state=2 
>
>The same goes for device 3.
>
>[  3291.220] (II) InputThreadUnregisterDev(fd=21) ... 
>[  3291.220] (II) InputThreadUnregisterDev: found a device: fd=21 state=1 
>[  3291.220] (II) inputh lock ...
>[  3291.232] (II) inputh locked
>[  3291.232] (II) dev fd=21 state=2 
>
>The same goes for device 4.
>
>[  3291.232] (II) InputThreadUnregisterDev(fd=22) ... 
>[  3291.232] (II) InputThreadUnregisterDev: found a device: fd=22 state=1 
>[  3291.232] (II) inputh lock ...
>[  3291.247] (II) inputh locked
>[  3291.247] (II) dev fd=22 state=2 
>
>The same goes for device 5.
>
>[  3291.247] (II) InputThreadUnregisterDev(fd=23) ... 
>[  3291.247] (II) InputThreadUnregisterDev: found a device: fd=23 state=1 
>[  3291.247] (II) inputh lock ...
>[  3291.259] (II) inputh locked
>[  3291.259] (II) dev fd=23 state=2 
>
>The same goes for device 6 in the main thread.
>
>[  3291.259] (II) InputThreadUnregisterDev(fd=24) ... 
>[  3291.259] (II) InputThreadUnregisterDev: found a device: fd=24 state=1 
>
>Now the last dev->state is set.
>Time for input thread to acquire the lock and detach the device.
>
>[  3291.259] (II) inputh lock ...
>
>Input thread now waits on the lock.
>The lock, however, is held by the main thread.
>
>Where? In the xf86DisableDevicesForVTSwitch.
>What for? So that input thread suspends for while on another VT.
>What this is for? So that there is no accidental input processing by programming mistake.
>
>So input thread would not be able to process the events until VT is switched back.
>
>User does Ctrl-Alt-F7
>
>Xserver re-initializes the monitor.
>
>[  3292.388] (II) modeset(0): <..>
><..>
>[  3292.388] (II) modeset(0): <..>
>
>Xserver's main thread now attaches input devices.
>(By just setting the dev->state).
>
>[  3292.501] (II) InputThreadRegisterDev(fd=19) ... 
>[  3292.501] (II) InputThreadRegisterDev(fd=20) ... 
>[  3292.501] (II) InputThreadRegisterDev(fd=21) ... 
>[  3292.501] (II) InputThreadRegisterDev(fd=22) ... 
>[  3292.501] (II) InputThreadRegisterDev(fd=23) ... 
>
>It does this for first five devices.
>For sixth, it sees a matching dev
>(the unprocessed one, with dev->state == device_state_removed).
>
>And does not signal (by means of dev->state)
>the input thread to attach the device.
>
>[  3292.501] (II) InputThreadRegisterDev(fd=24) ... 
>[  3292.501] (II) InputThreadRegisterDev: found a device: fd=24 state=2 
>
>The main thread is now done with all the six devices OS has.
>It releases input lock that was being held all the VT switch.
>
>Input thread acquires the long-awaited lock.
>
>[  3292.502] (II) inputh locked
>
>Now input thread would process six dev->state-s.
>
>[  3292.502] (II) dev fd=19 state=0 
>[  3292.502] (II) dev fd=20 state=0 
>[  3292.502] (II) dev fd=21 state=0 
>[  3292.502] (II) dev fd=22 state=0 
>[  3292.502] (II) dev fd=23 state=0 
>
>It sees five devices attached and one running.
>
>The sixth device does not get attached (by the input thread), hence the bug.
>
>
>Now timeout for Xserver expires, and it is sent a SIGTERM.
>
>[  3306.673] (II) InputThreadUnregisterDev(fd=19) ... 
>[  3306.673] (II) InputThreadUnregisterDev: found a device: fd=19 state=1 
>[  3306.674] (II) inputh lock ...
>[  3306.684] (II) inputh locked
>[  3306.684] (II) dev fd=19 state=2 
>[  3306.684] (II) InputThreadUnregisterDev(fd=20) ... 
>[  3306.684] (II) InputThreadUnregisterDev: found a device: fd=20 state=1 
>[  3306.684] (II) inputh lock ...
>[  3306.696] (II) inputh locked
>[  3306.696] (II) dev fd=20 state=2 
>[  3306.696] (II) InputThreadUnregisterDev(fd=21) ... 
>[  3306.696] (II) InputThreadUnregisterDev: found a device: fd=21 state=1 
>[  3306.696] (II) inputh lock ...
>[  3306.708] (II) inputh locked
>[  3306.708] (II) dev fd=21 state=2 
>[  3306.708] (II) InputThreadUnregisterDev(fd=22) ... 
>[  3306.708] (II) InputThreadUnregisterDev: found a device: fd=22 state=1 
>[  3306.708] (II) inputh lock ...
>[  3306.720] (II) inputh locked
>[  3306.720] (II) dev fd=22 state=2 
>[  3306.720] (II) InputThreadUnregisterDev(fd=23) ... 
>[  3306.720] (II) InputThreadUnregisterDev: found a device: fd=23 state=1 
>[  3306.720] (II) inputh lock ...
>[  3306.732] (II) inputh locked
>[  3306.732] (II) dev fd=23 state=2 
>[  3306.732] (II) InputThreadUnregisterDev(fd=24) ... 
>[  3306.732] (II) InputThreadUnregisterDev: found a device: fd=24 state=1 
>[  3306.732] (II) inputh lock ...
>[  3306.744] (II) inputh locked
>[  3306.744] (II) dev fd=24 state=2 
>[  3306.744] (II) evdev: <..>: Close
>[  3306.744] (II) UnloadModule: "evdev"
>[  3306.744] (II) evdev: <..>: Close
>[  3306.744] (II) UnloadModule: "evdev"
>[  3306.744] (II) evdev: <..>: Close
>[  3306.744] (II) UnloadModule: "evdev"
>[  3306.744] (II) evdev: Power Button: Close
>[  3306.744] (II) UnloadModule: "evdev"
>[  3306.745] (II) evdev: Video Bus: Close
>[  3306.745] (II) UnloadModule: "evdev"
>[  3306.745] (II) evdev: Power Button: Close
>[  3306.745] (II) UnloadModule: "evdev"
>[  3306.767] (II) Server terminated successfully (0). Closing log file.

Actions: View

Attachments on bug 97880: 126676 | 126702 | 126746 | 126759 | 127144 | 127145

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.