bpftrace -e 'kprobe:vfs_read { @start[tid] = nsecs; } kretprobe:vfs_read /@start[tid]/ { @ns = hist(nsecs - @start[tid]); delete(@start[tid]); }'perf probe --add vfs_read && perf record -e probe:vfs_read -aR sleep 10
ftrace echo vfs_read > /sys/kernel/debug/tracing/set_ftrace_filter
systemtap -e 'probe kernel.function("vfs_read") { println($$vars) }'
这道题你会答吗?花几分钟告诉大家答案吧!