Re: [PATCH 6/6] drm/i915: Fix lock order reversal in GEM relocationentry copying. -- makes X hang

From: Florian Mickler
Date: Mon Mar 30 2009 - 06:35:02 EST


Hi!

On Wed, 25 Mar 2009 14:45:10 -0700
Eric Anholt <eric@xxxxxxxxxx> wrote:

> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> Reviewed-by: Keith Packard <keithp@xxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_gem.c | 187
> +++++++++++++++++++++++++++----------- 1 files changed, 133
> insertions(+), 54 deletions(-)
>

I testet Linus' Git tree @ 5d80f8e5a (merge
net-2.6) and discovered that X hung after starting up gdm.

When i start gdm the screen is frozen and X hangs.
I was able to bisect it down to

40a5f0decdf050785ebd62b36ad48c869ee4b384 drm/i915: Fix lock order
reversal in GEM relocation entry copying.


when hung /proc/[xpid]/stack did contain:

[<ffffffff8024c13e>] msleep_interruptible+0x2e/0x40
[<ffffffff80557fdd>] i915_wait_ring+0x17d/0x1d0
[<ffffffff8056280d>] i915_gem_execbuffer+0xd2d/0xf70
[<ffffffff80546555>] drm_ioctl+0x1f5/0x320
[<ffffffff802d8ce5>] vfs_ioctl+0x85/0xa0
[<ffffffff802d8f0b>] do_vfs_ioctl+0x20b/0x510
[<ffffffff802d9297>] sys_ioctl+0x87/0xa0
[<ffffffff8020ba8b>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff


I reverted that commit now on top of 5d80f8e5a and all 's well .


My X-Stack is from Git at around 20th march. I will update that now,
but as it hangs in a kernel syscall, it shouldn't matter?

Sincerely,

Florian

p.s. no kms

Attachment: config.gz
Description: GNU Zip compressed data