Since regular compaction may run in parallel no lock
is required per-table.
We still acquire a read lock in this patch, for backporting
purposes, in case the branch doesn't contain
6737c88045.
But it can be removed entirely in master in a follow-up patch.
This should solve some of the slowness in cleanup compaction (and
likely in upgrade sstables seen in #10060, and
possibly #10166.
Fixes#10175
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#10177
11ea2ffc3c