Re: [PATCH 1/3] mm/slub: fix the race between validate_slab and slab_free

From: Rongwei Wang
Date: Mon Jun 13 2022 - 22:55:48 EST




On 6/13/22 9:50 PM, Christoph Lameter wrote:
On Sat, 11 Jun 2022, Rongwei Wang wrote:

Ok so the idea is to take the lock only if kmem_cache_debug. That looks
ok. But it still adds a number of new branches etc to the free loop.

Some performance tests would be useful.
Hi Christoph

Thanks for your time!
Do you have some advice in benchmarks that need me to test? And I find that
hackbench and lkp was used frequently in mm/slub.c commits[1,2]. But I have no
idea how to use these two benchmarks test to cover the above changes. Can you
give some examples? Thanks very much!


Hi Rongwei,

Well run hackbench with an without the change.
OK

There are also synthetic benchmarks available at
https://gentwo.org/christoph/slub/tests/
That's great, thanks very much!

These measure the cycles that slab operations take. However, they are a
bit old and I think Pekka may have a newer version of these
patches.

Greetings,
Christoph