updated man pages

man/man8/bashreadline.8

@@ -10,6 +10,10 @@ entered command may fail: this is just showing what was entered.
 
 This program is also a basic example of eBPF/bcc and uprobes.
 
+This makes use of a Linux 4.5 feature (bpf_perf_event_output()); 
+for kernels older than 4.5, see the version under tools/old,
+which uses an older mechanism
+
 Since this uses BPF, only the root user can use this tool.
 .SH REQUIREMENTS
 CONFIG_BPF and bcc.

man/man8/biosnoop.8

@@ -12,8 +12,9 @@ the I/O was first created (which usually identifies the responsible process).
 This uses in-kernel eBPF maps to cache process details (PID and comm) by I/O
 request, as well as a starting timestamp for calculating I/O latency.
 
-This works by tracing various kernel blk_*() functions using dynamic tracing,
-and will need updating to match any changes to these functions.
+This makes use of a Linux 4.5 feature (bpf_perf_event_output());
+for kernels older than 4.5, see the version under tools/old,
+which uses an older mechanism
 
 Since this uses BPF, only the root user can use this tool.
 .SH REQUIREMENTS