Offering: HULK
hulk inclusion
category: feature
bugzilla: N/A

--------------------------------

BMC is an in-kernel key-value cache implemented in BPF and proposed by
paper [1]. The paper discussed BMC for memcached, obtaining at least
6x performance speedup.

This patch implements a sample BMC for Redis.

See [2] for details on how to build samples/bpf.

Output files:
 samples/bpf/bmctool
 samples/bpf/bmc/bpf.o

Sample usage:
 bmctool prog load -p 6379 ./bmc/bpf.o  # load bmc bpf prog and attach it
                                        # to sockets with listen port 6379

 bmctool stat                           # dump bmc status

 bmctool prog unload                    # detach and unload bmc prog

Tested with the following command:

 ./redis-benchmark -c 20 -r 1 -n 1000 -t get  -h 192.168.4.101 -d 102

Without BMC:
  throughput summary: 41666.67 requests per second
  latency summary (msec):
          avg       min       p50       p95       p99       max
        0.441     0.176     0.415     0.631     1.455     1.815

With BMC (100% HIT):
  throughput summary: 66666.67 requests per second
  latency summary (msec):
          avg       min       p50       p95       p99       max
        0.223     0.096     0.215     0.311     0.743     0.759

BMC Stat:
 Total GET Requests: 1000
 Hit GET Requests: 1000 (100.00%)
 Dropped GET Requests: 0 (0.00%)
 Total SET Requests: 1
 Hit SET Requests: 1 (100.00%)
 Dropped SET Requests: 0 (0.00%)

[1] https://www.usenix.org/conference/nsdi21/presentation/ghigoff
[2] https://www.kernel.org/doc/readme/samples-bpf-README.rstSigned-off-by: NXu Kuohai <xukuohai@huawei.com>
Signed-off-by: NYang Jihong <yangjihong@huawei.com>
Signed-off-by: He Fengqing <hefengqing@huawei.com> (original demo)