Re: [PATCH v2 2/3] mm, page_owner: decouple freeing stack trace from debug_pagealloc

[Qian Cai]

> On Sep 30, 2019, at 5:43 PM, Vlastimil Babka <vbabka@xxxxxxx> wrote:
> 
> Well, my use case is shipping production kernels with CONFIG_PAGE_OWNER
> and CONFIG_DEBUG_PAGEALLOC enabled, and instructing users to boot-time
> enable only for troubleshooting a crash or memory leak, without a need
> to install a debug kernel. Things like static keys and page_ext
> allocations makes this possible without CPU and memory overhead when not
> boot-time enabled. I don't know too much about KASAN internals, but I
> assume it's not possible to use it that way on production kernels yet?

In that case, why canât users just simply enable page_owner=on and debug_pagealloc=on for troubleshooting? The later makes the kernel slower, but I am not sure if it is worth optimization by adding a new parameter. There have already been quite a few MM-related kernel parameters that could tidy up a bit in the future.