Bugzilla 1942: when a primary process exits cleanly, secondary processes other than testpmd do not get notified. The notification mechanism added in 25.11 was placed in testpmd and used rte_mp_request_sync() with a testpmd-specific action name, so any non-testpmd secondary (dpdk-dumpcap, dpdk-pdump, dpdk-procinfo, or out-of-tree consumers) would log "Cannot find action: mp_testpmd" and the primary would block on the 5 second request timeout.
Putting application-specific IPC actions on a broadcast request path is the wrong layer. Notification of primary exit is something every secondary needs and should come from EAL, not from each application. Patch 1 reverts the testpmd-side mechanism (commit f96273c8e9d3). The secondary-side primary alive monitor (enable_primary_monitor) is preserved and continues to handle detection of primary exit via the existing alarm-based polling of rte_eal_primary_proc_alive(). Patch 2 adds a generic EAL-level notification. On primary cleanup, rte_mp_channel_cleanup() broadcasts an MP_REQ_QUIT message to all known secondaries via rte_mp_sendmsg(). Secondaries register an internal action handler that tears down their own MP channel on receipt. No new public API; no application changes required for any secondary, in-tree or out. This is the minimum fix suitable for backport to 25.11 stable. It addresses the clean exit case. The crash case (primary killed or signaled) continues to be handled by the existing rte_eal_primary_proc_alive() polling on the secondary side, which detects the primary's release of the config file lock. A more complete solution using a connected socket type (SOCK_SEQPACKET) is planned since that can handle both planned and forced exiting of the primary. Tested with testpmd (primary) and dpdk-dumpcap, dpdk-pdump, dpdk-procinfo (secondaries). Stephen Hemminger (2): Revert "app/testpmd: stop forwarding in secondary process" eal: notify secondary on primary exit app/test-pmd/testpmd.c | 103 ++----------------------------- lib/eal/common/eal_common_proc.c | 51 ++++++++++++++- 2 files changed, 53 insertions(+), 101 deletions(-) -- 2.53.0
