On Wed, Sep 29, 2021 at 01:28:53PM +0100, Kevin Traynor wrote: > Hi Bruce, > > On 24/09/2021 17:18, Bruce Richardson wrote: > > When DPDK is run with --in-memory mode, multiple processes can run > > simultaneously using the same runtime dir. This leads to each process > > removing another process' telemetry socket as it started up, giving > > unexpected behaviour. > > > > This patch changes that behaviour to first check if the existing socket > > is active. If not, it's an old socket to be cleaned up and can be > > removed. If it is active, telemetry initialization fails and an error > > message is printed out giving instructions on how to remove the error; > > either by using file-prefix to have a different runtime dir (and > > therefore socket path) or by disabling telemetry if it not needed. > > > > telemetry is enabled by default but it may not be used by the application. > Hitting this issue will cause rte_eal_init() to fail which will probably > stop or severely limit the application. > > So it could change a working application to a non-working one (albeit one > that doesn't interfere with other process' sockets). > > Can it just print a warning that telemetry will not be enabled and continue > so it's not returning an rte_eal_init failure? >
For a backported fix, yes, that would probably be better behaviour, but for the latest branch, I think returning error and having the user explicitly choose the resolution they want to occur is best. I'll see about doing a separate backport patch for 20.11. > A more minor thing, I see it changes the behaviour from, last one runs with > telemetry, to, first one runs with telemetry. Though it can be figured from > the commit message, it might be worth calling that change out explicitly. > Sure. I'll resubmit a new version of this without stable CC'ed and include that behaviour change explicitly in the commit log. /Bruce
