Change eats memory on my server

[Thomas Zimmermann]

Hi

Am 18.01.21 um 10:13 schrieb Eli Cohen:
> On Mon, Jan 18, 2021 at 08:54:07AM +0100, Thomas Zimmermann wrote:
>> Hi
>>
>> Am 18.01.21 um 08:43 schrieb Christian König:
>>> Hi Eli,
>>>
>>> have you already tried using kmemleak?
>>>
>>> This sounds like a leak of memory allocated using kmalloc(), so kmemleak
>>> should be able to catch it.
>>
>> I have an idea what happens here. When the refcount is 0 in kmap, a new page
>> mapping for the BO is being established. But VRAM helpers unmap the previous
>> pages only on BO moves or frees; not in kunmap. So the old mapping might
>> still be around. I'll send out a test patch later today.
>>
> 
> Great! Looking forward to test it.

Here's the patch against the latest DRM tree. v5.11-rc3 should work as well.

I was able to reproduce the memory leak locally and found that the patch 
fixes it. Please give it a try.

Best regards
Thomas

> 
>> Best regards
>> Thomas
>>
>>>
>>> Regards,
>>> Christian.
>>>
>>> Am 17.01.21 um 06:08 schrieb Eli Cohen:
>>>> On Fri, Jan 15, 2021 at 10:03:50AM +0100, Thomas Zimmermann wrote:
>>>>> Could you please double-check that 3fb91f56aea4 ("drm/udl: Retrieve USB
>>>>> device from struct drm_device.dev") works correctly
>>>> Checked again, it does not seem to leak.
>>>>
>>>>> and that 823efa922102
>>>>> ("drm/cma-helper: Remove empty drm_gem_cma_prime_vunmap()") is broken?
>>>>>
>>>> Yes, this one leaks, as does the one preceding it:
>>>>
>>>> 1086db71a1db ("drm/vram-helper: Remove invariant parameters from
>>>> internal kmap function")
>>>>> For one of the broken commits, could you please send us the output of
>>>>>
>>>>>     dmesg | grep -i drm
>>>>>
>>>>> after most of the memory got leaked?
>>>>>
>>>> I ran the following script in the shell:
>>>>
>>>> while true; do cat /proc/meminfo | grep MemFree:; sleep 5; done
>>>>
>>>> and this is what I saw before I got disconnected from the shell:
>>>>
>>>> MemFree:          148208 kB
>>>> MemFree:          148304 kB
>>>> MemFree:          146660 kB
>>>> Connection to nps-server-24 closed by remote host.
>>>> Connection to nps-server-24 closed.
>>>>
>>>>
>>>> I also mointored the output of dmesg | grep -i drm
>>>> The last output I was able to save on disk is this:
>>>>
>>>> [   46.140720] ast 0000:03:00.0: [drm] Using P2A bridge for configuration
>>>> [   46.140737] ast 0000:03:00.0: [drm] AST 2500 detected
>>>> [   46.140754] ast 0000:03:00.0: [drm] Analog VGA only
>>>> [   46.140772] ast 0000:03:00.0: [drm] dram MCLK=800 Mhz type=7
>>>> bus_width=16
>>>> [   46.153553] [drm] Initialized ast 0.1.0 20120228 for 0000:03:00.0
>>>> on minor 0
>>>> [   46.165097] fbcon: astdrmfb (fb0) is primary device
>>>> [   46.391381] ast 0000:03:00.0: [drm] fb0: astdrmfb frame buffer device
>>>> [   56.097697] systemd[1]: Starting Load Kernel Module drm...
>>>> [   56.343556] systemd[1]: modprobe at drm.service: Succeeded.
>>>> [   56.350382] systemd[1]: Finished Load Kernel Module drm.
>>>> [13319.469462] [   2683] 70889  2683    55586        0    73728
>>>> 138             0 tdrm
>>>> [13320.658386] [   2683] 70889  2683    55586        0    73728
>>>> 138             0 tdrm
>>>> [13321.800970] [   2683] 70889  2683    55586        0    73728
>>>> 138             0 tdrm
>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>> -- 
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Maxfeldstr. 5, 90409 Nürnberg, Germany
>> (HRB 36809, AG Nürnberg)
>> Geschäftsführer: Felix Imendörffer
>>
> 
> 
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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