On Mon, Mar 28, 2022 at 11:04:36PM -0700, Tyler Retzlaff wrote:
> hi,
>
> there is a repeatable test failure in test_memzone when running
> dpdk-test.exe --no-huge for memzone_autotest
>
> it's clear why the test fails but what isn't clear if what
> rte_memzone_reserve is doing when provided an invalid socket id is
> sensible or not.
>
> as a matter of luck the system i'm using to test is a single socket
> system and as a result has only socket_id 0. the test however tries to
> use rte_memzone_reserve with a socket_id of 1 which is not a valid
> socket_id on the system.
>
> memzone3 = rte_memzone_reserve(TEST_MEMZONE_NAME("testzone3"), 1000,
> 1, 0);
> ^ socket_id (to repeat just make it invalid)
>
> the parameter documentation provided for reference.
>
> * @param socket_id
> * The socket identifier in the case of
> * NUMA. The value can be SOCKET_ID_ANY if there is no NUMA
> * constraint for the reserved zone.
>
> of interest is should rte_memzone_reserve fail when provided a
> completely invalid socket_id?
>
> when running with --no-huge it does not because when --no-huge the
> socket_id no matter the value is silently re-mapped to SOCKET_ID_ANY
> though without --no-huge if a completely garbage socket_id were provided
> it seems the allocation would fail.
>
> so you get different behavior for an invalid socket_id depending on
> --no-huge vs with.
>
> if (!rte_eal_has_hugepages() && socket_id < RTE_MAX_NUMA_NODES)
> socket_id = SOCKET_ID_ANY;
>
> the test later fails at this check. where it compares the memzone3
> socket_id to what was used in the call to rte_memzone_reserve.
>
> if (memzone3 != NULL && memzone3->socket_id != 1)
> return -1; ^ SOCKET_ID_ANY if --no-huge
>
> if the allocation had failed, the test would pass instead of failing at
> this point.
>
> so what's wrong here? the test should be changed to expect different
> behavior with --no-huge vs huge or should rte_memzone_reserve be
> explicitly requiring SOCKET_ID_ANY instead of re-mapping invalid socket
> id?
>
> if it isn't the test that is wrong then a compatibility discussion is of
> interest but i'm avoiding that until someone confirms the intended
> design/behavior.
>
> thanks
ping? does the community have an opinion here?
