sysconf(_SC_LEVEL3_CACHE_SIZE) returns 0

[foriequal0]

We tested in following environment:

Cloud provider: Tencent Cloud.
Kubernetes: TKE 1.20.6-tke.27, containerd 1.4.3
Node: S3.8XLARGE64, Intel(R) Xeon(R) Platinum 8255C CPU @ 2.50GHz
OS/Kernel: tlinux2.6(tkernel4)x86_64 / 5.4.119-1-tlinux4-0010.1
Pod image: aspnet:7.0.4

$ cat /sys/devices/system/cpu/cpu0/cache/index*/size
32K
32K
4096K
36608K

We can't confirm that L2 is correct since we can't find any intel spec sheet of 8255C, but L3 size is coherent with many different sources.

But getconf (which is implemented using sysconf) says L2 is 2048K, and L3 is 0:

$ getconf -a | grep CACHE
LEVEL1_ICACHE_SIZE                 32768
LEVEL1_ICACHE_ASSOC                8
LEVEL1_ICACHE_LINESIZE             64
LEVEL1_DCACHE_SIZE                 32768
LEVEL1_DCACHE_ASSOC                8
LEVEL1_DCACHE_LINESIZE             64
LEVEL2_CACHE_SIZE                  2097152
LEVEL2_CACHE_ASSOC                 8
LEVEL2_CACHE_LINESIZE              64
LEVEL3_CACHE_SIZE                  0
LEVEL3_CACHE_ASSOC                 0
LEVEL3_CACHE_LINESIZE              0
LEVEL4_CACHE_SIZE                  0
LEVEL4_CACHE_ASSOC                 0
LEVEL4_CACHE_LINESIZE              0