| created | 2024-02-13T07:25:15Z |
|---|---|
| begin | 2024-02-09T16:52:58Z |
| end | 2024-02-09T17:42:18Z |
| path | src/sys |
| commits | 1 |
| date | 2024-02-09T17:42:18Z | |||
|---|---|---|---|---|
| author | cheloha | |||
| files | src/sys/dev/dt/dt_dev.c | log | diff | annotate |
| src/sys/dev/dt/dt_prov_profile.c | log | diff | annotate | |
| src/sys/dev/dt/dtvar.h | log | diff | annotate | |
| src/sys/kern/kern_clock.c | log | diff | annotate | |
| message |
dt(4): move interval/profile entry points to dedicated clockintr callback To improve the utility of dt(4)'s interval and profile probes we need to move the probe entry points from the fixed-frequency hardclock() to a dedicated clock interrupt callback so that the probes can fire at arbitrary frequencies. - Remove entry points for interval/profile probes from hardclock(). - Merge dt_prov_profile_enter(), dt_prov_interval_enter(), and dt_prov_profile_fire() into one function, dt_clock(). This is the now-unified callback for interval/profile probes. dt_clock() will consume multiple events during a single execution if it is delayed, but on platforms with high quality interrupt clocks this should be rare. - Each struct dt_pcb gets its own clockintr handle, dp_clockintr. - In struct dt_pcb, replace dp_maxtick/dp_nticks with dp_nsecs, the PCB's sampling period. Aynchronous probes must initialize dp_nsecs to a non-zero value during dtpv_alloc(). - In struct dt_pcb, replace dp_cpuid with dp_cpu so that dt_ioctl_record_start() knows where to bind the PCB's dp_clockintr. - dt_ioctl_record_start() binds, staggers, and starts all interval/profile PCBs on the given dt_softc. Each dp_clockintr is given a reference to its enclosing PCB so that dt_clock() doesn't need to search for it. The staggering sort-of simulates the current behavior under hardclock(). - dt_ioctl_record_stop() unbinds all interval/profile PCBs. The CL_BARRIER ensures that dp_clockintr's PCB reference is not in use by dt_clock() so that the PCB may be safely freed upon return from dt_ioctl_record_stop(). Blocking while holding dt_lock is not ideal, but in practice blocking in this spot is rare and dt_clock() completes quickly on all but the oldest hardware. An extremely unlucky thread could block for every interval/profile PCB on the softc, but this is implausible. DT_FA_PROFILE values are up-to-date for amd64, i386, and macppc. Somebody with the right hardware needs to check-and-maybe-fix the values on octeon, powerpc64, and sparc64. Joint effort with mpi@. Thread: https://marc.info/?l=openbsd-tech&m=170629371821879&w=2 ok mpi@ |
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