Minor cleanups by commiter.
(source commit 43ff10204b1d9b76f6d5afc5252fb09480d5ffc5 but expected
to be rebased later, don't worry if you fail to find it)
Functions flow_check_cf_bmk_values, flow_check_cf_value_length,
flow4_validate_cf and flow6_validate_cf are now not built with lib but
with conf to enable for better semantic separation.
Different internal allocators (memory blocks, linpools, and slabs) used
different way to compute alignment. Unify it to use alignment based on
standard max_align_t type.
On x86_64, this does not change alignment of memory blocks and linpools
(both old and new is 16), but it increases alignment of slabs from 8 to
16.
Minor changes by commiter.
Best route refeed is tricky. The journal may include repeatedly the same
route in the old and/or in the new position in case of flaps. We don't
like checking that fully in the RCU critical section which is already
way too long, thus we filter out the repeated occurence of the current
best route while keeping possibly more old routes.
We also don't want to send spurious withdraws, and we need to check that
only one notification per net is sent for RA_OPTIMAL.
There was also missing a rejected map update in case of idempotent
squashed update, and last but not least, the best route journal should
not include invalid routes (import keep filtered).
Even though allocating from tmp_linpool is quite cheap,
it isn't cheap when the block is larger than a page, which is the case here.
Instead, we now allocate just the result which typically fits in a page,
avoiding a necessity of a malloc().
To mid-term allocate and free lots of small blocks in a fast pace,
mb_alloc is too slow and causes heap bloating. We can already allocate
blocks from slabs, and if we allow for a little bit of inefficiency,
we can just use multiple slabs with stepped sizes.
This technique is already used in ea_list allocation which is gonna be
converted to Stonehenge.
