[release/1.7 backport] runtime/v2/runc: handle early exits w/o big locks

[corhere]

• backport of runtime/v2/runc: handle early exits w/o big locks #8617
• fixes Concurrent task execs take significantly longer than sequentially #8557

⚠️ ran into a conflict in service.handleProcessExit / service.checkProcesses, due to commit 6f34da5 not being in the 1.7 branch.

---

eventSendMu is causing severe lock contention when multiple processes start and exit concurrently. Replace it with a different scheme for maintaining causality w.r.t. start and exit events for a process which does not rely on big locks for synchronization.

Keep track of all processes for which a Task(Exec)Start event has been published and have not yet exited in a map, keyed by their PID. Processing exits then is as simple as looking up which process corresponds to the PID. If there are no started processes known with that PID, the PID must either belong to a process which was started by s.Start() and before the s.Start() call has added the process to the map of running processes, or a reparented process which we don't care about. Handle the former case by having each s.Start() call subscribe to exit events before starting the process. It checks if the PID has exited in the time between it starting the process and publishing the TaskStart event, handling the exit if it has. Exit events for reparented processes received when no s.Start() calls are in flight are immediately discarded, and events received during an s.Start() call are discarded when the s.Start() call returns.

(cherry picked from commit 5cd6210)

[k8s-ci-robot]

Hi @corhere. Thanks for your PR.

I'm waiting for a containerd member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[thaJeztah]

LGTM

[dcantah]

Thanks LGTM

[corhere]

[FAIL] [k8s.io] Container runtime should support basic operations on container [It] runtime should support listing stats for three created containers when filter is nil. [Conformance]
github.com/kubernetes-sigs/cri-tools/pkg/validate/container.go:671

The same test is also failing on the current head of the 1.7 branch, so is most likely unrelated to the changes in this PR.

[laurazard]

LGTM ❤️

[dcantah]

[FAIL] [k8s.io] Container runtime should support basic operations on container [It] runtime should support listing stats for three created containers when filter is nil. [Conformance]

github.com/kubernetes-sigs/cri-tools/pkg/validate/container.go:671

The same test is also failing on the current head of the 1.7 branch, so is most likely unrelated to the changes in this PR.

Yea, it's unrelated