Messages in this thread | | | From | Toke Høiland-Jørgensen <> | Subject | Re: [PATCH net-next] page_pool: disable direct recycling based on pool->cpuid on destroy | Date | Thu, 15 Feb 2024 13:05:30 +0100 |
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Alexander Lobakin <aleksander.lobakin@intel.com> writes:
> Now that direct recycling is performed basing on pool->cpuid when set, > memory leaks are possible: > > 1. A pool is destroyed. > 2. Alloc cache is emptied (it's done only once). > 3. pool->cpuid is still set. > 4. napi_pp_put_page() does direct recycling basing on pool->cpuid. > 5. Now alloc cache is not empty, but it won't ever be freed.
Did you actually manage to trigger this? pool->cpuid is only set for the system page pool instance which is never destroyed; so this seems a very theoretical concern?
I guess we could still do this in case we find other uses for setting the cpuid; I don't think the addition of the READ_ONCE() will have any measurable overhead on the common arches?
-Toke
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