Re: [PATCH] mm/slub: use stackdepot to save stack trace in objects

[Vlastimil Babka]

On 5/10/21 6:46 AM, Andrew Morton wrote:
> On Wed, 14 Apr 2021 18:34:34 +0200 glittao@xxxxxxxxx wrote:
> 
>> Many stack traces are similar so there are many similar arrays.
>> Stackdepot saves each unique stack only once.
>> 
>> Replace field addrs in struct track with depot_stack_handle_t handle.
>> Use stackdepot to save stack trace.
>> 
>> The benefits are smaller memory overhead and possibility to aggregate
>> per-cache statistics in the future using the stackdepot handle
>> instead of matching stacks manually.
> 
> Which tree was this prepared against?  5.12's kmem_obj_info() is
> significantly different from the version you were working on.

It was based on -next at the time of submission, which contained patch in Paul's
tree that expands kmem_obj_info to print also free call stack [1] so that also
needs to be switched to stackdepot to work.

> Please take a look, redo, retest and resend?  Thanks.

I expected [1] to be in 5.13-rc1, but as Paul explained to me, it's queued for
5.14. So if we (Oliver) rebase on current -next, can you queue it in the section
of mmotm series that goes after -next?

Vlastimil

[1]
https://lore.kernel.org/linux-arm-kernel/1615891032-29160-2-git-send-email-maninder1.s@xxxxxxxxxxx/