[PATCH v8 04/23] slab: add sheaf support for batching kfree_rcu() operations

[Vlastimil Babka]

On 11/27/25 12:38, Jon Hunter wrote:
> 
> 
> On 31/10/2025 21:32, Daniel Gomez wrote:
>> 
>> 
>> On 10/09/2025 10.01, Vlastimil Babka wrote:
>> 
>> Hi Vlastimil,
>> 
>> This patch increases kmod selftest (stress module loader) runtime by about
>> ~50-60%, from ~200s to ~300s total execution time. My tested kernel has
>> CONFIG_KVFREE_RCU_BATCHED enabled. Any idea or suggestions on what might be
>> causing this, or how to address it?
>> 
> 
> I have been looking into a regression for Linux v6.18-rc where time 
> taken to run some internal graphics tests on our Tegra234 device has 
> increased from around 35% causing the tests to timeout. Bisect is 
> pointing to this commit and I also see we have CONFIG_KVFREE_RCU_BATCHED=y.

Do the tegra tests involve (frequent) module unloads too, then? Or calling
kmem_cache_destroy() somewhere?

Thanks,
Vlastimil

> I have not tried disabling CONFIG_KVFREE_RCU_BATCHED=y but I can. I am 
> not sure if there are any downsides to disabling this?
> 
> Thanks
> Jon
>