open-iov.git/tools/guest-diag/track_waits.sh, branch m32

guest-diag: single-read counter sampler (kills phantom 4-of-20 view); vmrestart reaps stale watchers

2026-09-29T22:01:12+00:00

guest-diag: non-blocking trace tail + 100ms scan loop + raw counter-page dump

2026-09-29T20:51:57+00:00

- the trace tail (subprocess + 256KB read) ran inside the scan loop and blocked it for seconds exactly when the client's GR window appeared; moved to a background thread whose queue the loop drains. - scan interval 250ms -> 100ms. - track_waits sampler also dumps 512 raw bytes at page+0xe00 each sample: the per-slot reads disagreed with the bulk dump within one sample because host writes land between the two, and the raw dump is the only trustworthy view of the slot layout.

guest-diag: cheaper trace read, optional push sampler, bigger pagemap batches

2026-09-29T18:47:17+00:00

Under load the semfix poll grepped the whole (growing) trace file and the track_waits push block spawned three guest processes per sample, both of which slowed the pin path into the client's failure window. The trace read now tails 128 KB; track_waits.sh gates the push dump behind PUSH=0; the pagemap helper reads 32 KB chunks.

kernel: authoritative host-injected VA->PA pins (ipin table) + wider pin table

2026-09-29T17:52:49+00:00

The CE push-buffer page 0x120000000 resolved to a zero-filled page even after sema_map_add injected the correct translation: the shared pin table silently dropped inserts once a hash cluster exceeded the 32-probe window (the page hashes to slot 0, a hot cluster), and lookups fell through to the content-scanned map and answered with a stale page - so every CE push read as implausible and memset stayed 0. Injected translations now live in a separate authoritative table checked before every other source and are never written by self-discovery; the general pin table is 4x larger with a 4x probe window and counts drops (pin_drop/ipin_drop) in the stats line. guest_kprobes.sh disables the kprobe group before removal (EBUSY) and matches p:kprobes/; the guest wait sampler can run counters-only with GDB=0.

sema-svc: async VA->PA injection queue; guest-diag: fast counter+pin injector, wait sampler

2026-09-29T15:55:15+00:00