RE: amdgpu crashes on OOM

[Deucher, Alexander]

[AMD Public Use]

> -----Original Message-----
> From: Michel Dänzer <michel@xxxxxxxxxxx>
> Sent: Monday, October 26, 2020 7:04 AM
> To: Alex Xu (Hello71) <alex_y_xu@xxxxxxxx>; Kazlauskas, Nicholas
> <Nicholas.Kazlauskas@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Wentland, Harry
> <Harry.Wentland@xxxxxxx>; Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx>;
> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: amdgpu crashes on OOM
> 
> On 2020-10-26 5:29 a.m., Alex Xu (Hello71) wrote:
> > Hi,
> >
> > I frequently encounter OOM on my system, mostly due to my own fault.
> > Recently, I noticed that not only does a swap storm happen and OOM
> > killer gets invoked, but the graphics output freezes permanently.
> > Checking the kernel messages, I see:
> >
> > kworker/u24:4: page allocation failure: order:5,
> mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO),
> nodemask=(null)
> > CPU: 6 PID: 279469 Comm: kworker/u24:4 Tainted: G        W         5.9.0-14732-
> g20b1adb60cf6 #2
> > Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./B450
> > Pro4, BIOS P4.20 06/18/2020
> > Workqueue: events_unbound commit_work
> > Call Trace:
> >   ? dump_stack+0x57/0x6a
> >   ? warn_alloc.cold+0x69/0xcd
> >   ? __alloc_pages_direct_compact+0xfb/0x116
> >   ? __alloc_pages_slowpath.constprop.0+0x9c2/0xc14
> >   ? __alloc_pages_nodemask+0x143/0x167
> >   ? kmalloc_order+0x24/0x64
> >   ? dc_create_state+0x1a/0x4d
> >   ? amdgpu_dm_atomic_commit_tail+0x1b19/0x227d
> 
> Looks like dc_create_state should use kvzalloc instead of kzalloc
> (dc_state_free already uses kvfree).
> 
> order:5 means it's trying to allocate 32 physically contiguous pages, which can
> be hard to fulfill even with lower memory pressure.
> 

It was using kvzalloc, but was accidently dropped when that code was refactored.  I just sent a patch to fix it.

Alex

> 
> --
> Earthling Michel Dänzer               |
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