main: add high-performance clock - #716
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Reading the common clock, gr_clock_ns() -- implemented with clock_gettime() -- is quite slow, even though the kernel exposes it as a vDSO. For improved performance in the dataplane, introduce a high-performance clock: clock_ns(), based on snapshotting the common clock, for use where a snapshot is sufficiently accurate. Immediately before walking the graph in the dataplane worker thread's main loop, mark the clock as trusted and update it, so it is safe to use in the "process" functions of the graph nodes. Define GR_CLOCK_SOURCE (as CLOCK_MONOTONIC_RAW), to highlight which clock source is used by Grout. Add definitions like GR_NS_PER_S to help convert between nanoseconds and microseconds (GR_NS_PER_US) respectively milliseconds (GR_NS_PER_MS). Replace all direct calls to gr_clock_ns() in grout control and data plane with clock_ns() and update <gr_clock.h> include to "clock.h" accordingly. Signed-off-by: Morten Brørup <mb@smartsharesystems.com> Signed-off-by: Robin Jarry <rjarry@redhat.com>
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Reading the common clock, gr_clock_ns() -- implemented with clock_gettime() -- is quite slow, even though the kernel exposes it as a vDSO.
For improved performance in the dataplane, introduce a high-performance clock: clock_ns(), based on snapshotting the common clock, for use where a snapshot is sufficiently accurate.
Immediately before walking the graph in the dataplane worker thread's main loop, mark the clock as trusted and update it, so it is safe to use in the "process" functions of the graph nodes.
Define GR_CLOCK_SOURCE (as CLOCK_MONOTONIC_RAW), to highlight which clock source is used by Grout.
Add definitions like GR_NS_PER_S to help convert between nanoseconds and microseconds (GR_NS_PER_US) respectively milliseconds (GR_NS_PER_MS).
Replace all direct calls to gr_clock_ns() in grout control and data plane with clock_ns() and update <gr_clock.h> include to "clock.h" accordingly.
Respin of: https://patches.dpdk.org/project/grout/patch/20260827094041.520166-1-mb@smartsharesystems.com/
Cc: @MortenBroerup