[Bug 103638] [CI] igt at gem_exec_reuse@contexts - dmesg-warn - BUG: sleeping function called from invalid context at mm/vmalloc.c:1037

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=103638

Chris Wilson <chris at chris-wilson.co.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #1 from Chris Wilson <chris at chris-wilson.co.uk> ---
commit 94dec87159af6f3dcc0b78d3f909aefa9e29c01a
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Thu Nov 9 08:55:40 2017 +0000

    drm/i915: Reorder context-close to avoid calling i915_vma_close() under RCU

    When we close the VMA, we unbind it from the ppgtt and tear down the
    page directory pointing at it. That may trigger us to return WC pages
    back to the system, requiring conversion back to WB which itself may
    sleep. That makes i915_vma_close() unsuitable for use inside the RCU
    read lock, which we need to hold to iterate the radixtree.

    The fix is quite simple, we can close all the VMA as we close the ppgtt,
    we only need to do that instead of closing them during destruction of
    the LUT.

    v2: Order between closing the LUT and the ppgtt is important; we use the
    vma inside the LUT as a means of retrieving the object, and so we must
    clear the LUT before freeing the VMA when closing the ppgtt.

    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103638
    Fixes: 547da76b5777 ("drm/i915: Hold rcu_read_lock when iterating over the
radixtree (vma idr)")
    Fixes: d1b48c1e7184 ("drm/i915: Replace execbuf vma ht with an idr")
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
    Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
    Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
    Cc: Matthew Auld <matthew.william.auld at gmail.com>
    Link:
https://patchwork.freedesktop.org/patch/msgid/20171109085540.32264-1-chris@chris-wilson.co.uk
    Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are on the CC list for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20171109/fb69682a/attachment-0001.html>