Re: [PATCH net-next 3/3] bpf: Only set node->ref = 1 if it has not been set

On 8/31/17 11:27 PM, Martin KaFai Lau wrote:

This patch writes 'node->ref = 1' only if node->ref is 0.
The number of lookups/s for a ~1M entries LRU map increased by
~30% (260097 to 343313).

Other writes on 'node->ref = 0' is not changed.  In those cases, the
same cache line has to be changed anyway.

First column: Size of the LRU hash
Second column: Number of lookups/s

Before:

quoted

echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')"

1048577: 260097

After:

quoted

echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')"

1048577: 343313

Signed-off-by: Martin KaFai Lau <redacted>

Acked-by: Alexei Starovoitov <ast@kernel.org>