On Thu 04-05-23 09:22:07, Suren Baghdasaryan wrote:
[...]

quoted

But even then I really detest an additional allocation from this context
for every single allocation request. There GFP_NOWAIT allocation for
steckdepot but that is at least cached and generally not allocating.
This will allocate for every single allocation.

A small correction here. alloc_tag_create_ctx() is used only for
allocations which we requested to capture the context. So, this last
sentence is true for allocations we specifically marked to capture the
context, not in general.

Ohh, right. I have misunderstood that part. Slightly better, still
potentially a scalability issue because hard to debug memory leaks
usually use a generic caches (for kmalloc). So this might be still a lot
of objects to track.

quoted

There must be a better way.

Yeah, agree, it would be good to avoid allocations in this path. Any
specific ideas on how to improve this? Pooling/caching perhaps? I
think kmem_cache does some of that already but maybe something else?

The best I can come up with is a preallocated hash table to store
references to stack depots with some additional data associated. The
memory overhead could be still quite big but the hash tables could be
resized lazily.
-- 
Michal Hocko
SUSE Labs