On Fri, May 27, 2022 at 4:10 AM Zhang Yuchen <zhangyuchen.lcr@xxxxxxxxxxxxx> wrote: > > Add /proc/syscalls to display percpu syscall count. I second Peter's nack. We don't add debug features to the production kernel. > We need a less resource-intensive way to count syscall per cpu > for system problem location. > > There is a similar utility syscount in the BCC project, but syscount > has a high performance cost. There are two syscount tools in BCC: tools/syscount libbpf-tools/syscount Which one has this 42% overhead? The former tool is obsolete though. It was written in the days when bpf had 1/10 of the features it has today. Both tools can be optimized. They attach to raw_syscalls tracepoint. tracepoints are not cheap. In terms of overhead: tracepoint > raw_tracepoint > fentry. bpf can attach to all three. Please profile libbpf-tools/syscount tool with perf and unixbench, understand where overhead comes from and then optimize the tool.
