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

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