fib_hash: embed initial hash table in fn_zone

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While looking for false sharing problems, I noticed
sizeof(struct fn_zone) was small (28 bytes) and possibly sharing a cache
line with an often written kernel structure.

Most of the time, fn_zone uses its initial hash table of 16 slots.

We can avoid the false sharing problem by embedding this initial hash
table in fn_zone itself, so that sizeof(fn_zone) > L1_CACHE_BYTES

We did a similar optimization in commit a6501e080c (Reduce memory needs
and speedup lookups)

Add a fz_revorder field to speedup fn_hash() a bit.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Eric Dumazet 2010-10-14 20:53:04 +00:00 • committed by David S. Miller

parent 7fc4463309

commit 9bef83edfb

1 changed files with 23 additions and 29 deletions

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net/ipv4/fib_hash.c

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