Re: [dpdk-dev] [PATCH] mem: fix deadlock on secondary allocation

29/01/2021 17:07, Burakov, Anatoly:

On 29-Jan-21 3:40 PM, Thomas Monjalon wrote:

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29/01/2021 16:29, Anatoly Burakov:

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Previous fix used `rte_malloc_heap_socket_is_external()` to check if the
heap was an external heap. However, that API is thread-safe, and when
we're inside the allocation process, we're already write-locked, so
calling `rte_malloc_heap_socket_is_external()` will result in a
deadlock followed by a timeout.

Fix it by replacing the API call with a check against maximum number of
NUMA nodes, because external heaps always have higher socket ID's.

Is there some unit tests for such thing?

I couldn't reproduce this using autotests, but Jim has SPDK tests which 
triggered this error.

Since this is dependent upon secondary process, any test would 
necessarily have to be manual here, i think.

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Fixes: 7ac31e82bc8f ("mem: improve parameter checking on memory hotplug")

Reported-by: Jim Harris <redacted>

No need of blank line here.

Need to update my scripts :P

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Signed-off-by: Anatoly Burakov <redacted>
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[...]

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+	/*
+	 * for allocations, we must only use internal heaps, but since the
+	 * rte_malloc_heap_socket_is_external() is thread-safe and we're already
+	 * read-locked, we'll have to take advantage of the fac that internal

fac -> fact?

Yes.

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+	 * socket ID's are always lower than RTE_MAX_NUMA_NODES.
+	 */

Applied with minor changes, thanks.