Re: [PATCH] drm/pagemap: Drop ratelimiting from dev_unhold_work debug trace

["Gupta, Varun" <varun.gupta@intel.com>]

On 21-Sep-26 12:03 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] drm/pagemap: CPU stall re-introduced by unbounded drm_dbg() loop
> --
>
> commit ea1ff5e58f9772cc1eaec3db21133d24e24bd4f0
> Author: Varun Gupta <varun.gupta@intel.com>
>
> drm/pagemap: Drop ratelimiting from dev_unhold_work debug trace
>
> This commit reverts the use of drm_dbg_ratelimited back to drm_dbg in
> drm_pagemap_dev_unhold_work to avoid "callbacks suppressed" notifications
> from the kernel's ratelimiting subsystem.
>
>> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
>> index c66c58f85c345..743988036a5f8 100644
>> --- a/drivers/gpu/drm/drm_pagemap.c
>> +++ b/drivers/gpu/drm/drm_pagemap.c
>> @@ -1102,7 +1102,7 @@ static void drm_pagemap_dev_unhold_work(struct work_struct *work)
>>   		struct drm_device *drm = dev_hold->drm;
>>   		struct module *module = drm->driver->fops->owner;
>>   
>> -		drm_dbg_ratelimited(drm, "Releasing reference on provider device and module.\n");
>> +		drm_dbg(drm, "Releasing reference on provider device and module.\n");
> [Severity: Medium]
> Does this code re-introduce a serial console bottleneck and potential CPU stall
> during teardown?
This does not introduce a stall, it is handled by the WQ_UNBOUND change. 
This log was ratelimited to
just prevent log flooding but it in turn introduces a suppressed warning.
> When tearing down an unbounded number of DRM pagemaps,
> drm_pagemap_dev_unhold_work() iterates over the entire
> drm_pagemap_unhold_list. If DRM debugging is enabled, drm_dbg() is now
> called for every single entry unconditionally.
>
> If the goal is to prevent the "callbacks suppressed" warning from the
> ratelimiting subsystem, would it be better to drop the repetitive log
> entirely, or perhaps log once outside the loop, rather than reverting
> the CPU stall fix?
>
>>   		drm_dev_put(drm);
>>   		module_put(module);
>>   		kfree(dev_hold);