In this patch, for a given test, it is possible to override the knob
values, e.g.
[[test]]
[[test.knobs]]
watch_timeout = 999
will set the client knob WATCH_TIMEOUT to 999 during the test. The
original value will be recovered after the test is over.
* add knob for trace event severity
* add knob for TraceEvent severity
* fix format
* fix switch format
* moved intToSeverity call inside __test initialization
* updated knob name
* fix line length format
* fix format
* git clang-format
* Redwood files now growth in large page chunks controlled by a knob to reduce truncate() calls for expansion. PriorityMultiLock has limit on consecutive same-priority lock release. Increased Redwood max priority level to 3 for more separation at higher BTree levels.
* Simulation fix, don't mark certain IO timeout errors as injected unless the simulated process has been set to have an unreliable disk.
* Pager writes now truncate gradually upward, one chunk at a time, in response to writes, which wait on only the necessary truncate operations. Increased buggified chunk size because truncate can be very slow in simulation.
* In simulation, ioTimeoutError() and ioDegradedOrTimeoutError() will wait until at least the target timeout interval past the point when simulation is sped up.
* PriorityMultiLock::toString() prints more info and is now public.
* Added queued time to PriorityMultiLock.
* Bug fix to handle when speedUpSimulation changes later than the configured time.
* Refactored mutation application in leaf nodes to do fewer comparisons and do in place value updates if the new value is the same size as the old value.
* Renamed updatingInPlace to updatingDeltaTree for clarity. Inlined switchToLinearMerge() since it is only used in one place.
* Updated extendToCover to be more clear by passing in the old extension future as a parameter. Fixed initialization warning.
