• C
    drm/i915: Idle the GPU before shinking everything · 0676e794
    Chris Wilson 提交于
    The handling of contexts are peculiar. Instead of tieing their vma to
    activity, we pin the context. This means that we cannot simply unbind
    the context object itself at will (which would normally cause us to wait
    for the vma to be idle), but must manually idle the GPU and retire
    requests first.
    
    A consequence of this peculiarity is when doing a last desperate attempt
    to recover memory. If the memory is tied up inside active context
    objects, we will fail to recover any memory simply by trying to unbind
    the objects without first doing a wait-for-idle.
    
    A side-effect of removing the call to shrinker_lock_uninterruptible()
    from i915_gem_shrinker_oom() was that we removed an unlocked
    wait-for-idle, and so lost the "natural" shrinkage of context objects.
    By replacing that with a locked wait from inside i915_gem_shrink(), we
    not only replace it with the ability to recover all context objects, but
    do so for all i915_gem_shrink_all() callers.
    
    v2: Switching requires request allocation, which is not permitted from
    inside the shrinker as it only uses ordinary allocations.
    
    References: https://bugs.freedesktop.org/show_bug.cgi?id=102936
    Fixes: f2123818 ("drm/i915: Move dev_priv->mm.[un]bound_list to its own lock")
    Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
    Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20171108094400.1386-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
    (cherry picked from commit 2f6a3783)
    Signed-off-by: NJani Nikula <jani.nikula@intel.com>
    0676e794
i915_gem_shrinker.c 15.9 KB