Messages in this thread | | | Date | Fri, 15 Jan 2021 11:41:07 -0800 (PST) | From | David Rientjes <> | Subject | Re: [PATCH v2] mm/slub: disable user tracing for kmemleak caches by default |
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On Wed, 13 Jan 2021, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com> > > If kmemleak is enabled, it uses a kmem cache for its own objects. > These objects are used to hold information kmemleak uses, including > a stack trace. If slub_debug is also turned on, each of them has > *another* stack trace, so the overhead adds up, and on my tests (on > ARCH=um, admittedly) 2/3rds of the allocations end up being doing > the stack tracing. > > Turn off SLAB_STORE_USER if SLAB_NOLEAKTRACE was given, to avoid > storing the essentially same data twice. > > Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
> --- > Perhaps instead it should go the other way around, and kmemleak > could even use/access the stack trace that's already in there ... > But I don't really care too much, I can just turn off slub debug > for the kmemleak caches via the command line anyway :-) >
I think making the change to kmem_cache_flags() is likely the simplest.
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