user: custom mapSize flag. improve memory usage #433 .

[cfc4n]

used --map-size to set mapSize perCPU in cli. default:10240KB,

[cfc4n]

@h0x0er PTAL.

[h0x0er]

@cfc4n , PR Looks Good To Me 🚀. Thanks for the enhancements

[cfc4n]

Terminal 1

sudo free -m
[sudo] password for cfc4n:
               total        used        free      shared  buff/cache   available
Mem:            3876         477         277           1        3121        3106
Swap:           3893           0        3893

#### exec ecapture at other terminal.
sudo free -m
               total        used        free      shared  buff/cache   available
Mem:            3876         513         240           1        3121        3069
Swap:           3893           0        3893

Terminal 2

sudo bin/ecapture tls

and , openssl module create 3 ebpf maps.

{
    Name: "tls_events",
},
{
    Name: "connect_events",
},
{
    Name: "mastersecret_events",
},

• mapSizePerCPU = 5M
• 2 CPUS
• 3 eBPF maps

all eBPF maps used memory = 2 * 5 * 3 = 30MB.
now, eCapture used memory (include ebpf maps) = 513-477 ≈ 277-240 ≈ 36M .

As expected.