Re: [PATCH bpf-next v2 2/9] bpf: add bpf_get_stack helper

2018-04-18 Thread Alexei Starovoitov
On Wed, Apr 18, 2018 at 09:54:37AM -0700, Yonghong Song wrote: > Currently, stackmap and bpf_get_stackid helper are provided > for bpf program to get the stack trace. This approach has > a limitation though. If two stack traces have the same hash, > only one will get stored in the stackmap table, >

[PATCH bpf-next v2 2/9] bpf: add bpf_get_stack helper

2018-04-18 Thread Yonghong Song
Currently, stackmap and bpf_get_stackid helper are provided for bpf program to get the stack trace. This approach has a limitation though. If two stack traces have the same hash, only one will get stored in the stackmap table, so some stack traces are missing from user perspective. This patch impl