before this change, we returns the total memory managed by Seastar
in the "total" field in system.memory. but this value only reflect
the total memory managed by Seastar's allocator. if
`reserve_additional_memory` is set when starting app_template,
Seastar's memory subsystem just reserves a chunk of memory of this
specified size for system, and takes the remaining memory. since
f05d612da8, we set this value to 50MB for wasmtime runtime. hence
the test of `TestRuntimeInfoTable.test_default_content` in dtest
fails. the test expects the size passed via the option of
`--memory` to be identical to the value reported by system.memory's
"total" field.
after this change, the "total" field takes the reserved memory
for wasm udf into account. the "total" field should reflect the total
size of memory used by Scylla, no matter how we use a certain portion
of the allocated memory.
Fixes#12522
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#12573
4a0134a097