|vfscount(8)||System Manager's Manual||vfscount(8)|
vfscount.bt - Count VFS calls ("vfs_*"). Uses bpftrace/eBPF.
This counts VFS calls. This can be useful for general workload characterization of these operations.
This works by tracing all kernel functions beginning with "vfs_" using dynamic tracing. This may match more functions than you are interested in measuring: Edit the script to customize which functions to trace.
Since this uses BPF, only the root user can use this tool.
CONFIG_BPF and bpftrace.
- Count all VFS calls until Ctrl-C is hit:
- # vfscount.bt
- Kernel function name (in @)
- Number of calls while tracing
This traces kernel vfs functions and maintains in-kernel counts, which are asynchronously copied to user-space. While the rate of VFS operations can be very high (>1M/sec), this is a relatively efficient way to trace these events, and so the overhead is expected to be small for normal workloads. Measure in a test environment, and if overheads are an issue, edit the script to reduce the types of vfs functions traced (currently all beginning with "vfs_").
This is from bpftrace.
Also look in the bpftrace distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.
This is a bpftrace version of the bcc tool of the same name. The bcc tool may provide more options and customizations.
Unstable - in development.