Point people to tools/old

man/man8/memleak.8

@@ -16,6 +16,7 @@ memleak may introduce significant overhead when tracing processes that allocate
 and free many blocks very quickly. See the OVERHEAD section below.
 
 This tool only works on Linux 4.6+. Stack traces are obtained using the new BPF_STACK_TRACE` APIs.
+For kernels older than 4.6, see the version under tools/old.
 .SH REQUIREMENTS
 CONFIG_BPF and bcc.
 .SH OPTIONS

man/man8/offcputime.8

@@ -24,6 +24,7 @@ See http://www.brendangregg.com/FlameGraphs/offcpuflamegraphs.html
 
 This tool only works on Linux 4.6+. It uses the new `BPF_STACK_TRACE` table
 APIs to generate the in-kernel stack traces.
+For kernels older than 4.6, see the version under tools/old.
 .SH REQUIREMENTS
 CONFIG_BPF and bcc.
 .SH OPTIONS

man/man8/stackcount.8

@@ -13,6 +13,7 @@ The pattern is a string with optional '*' wildcards, similar to file globbing.
 If you'd prefer to use regular expressions, use the \-r option.
 
 This tool only works on Linux 4.6+. Stack traces are obtained using the new `BPF_STACK_TRACE` APIs.
+For kernels older than 4.6, see the version under tools/old.
 
 .SH REQUIREMENTS
 CONFIG_BPF and bcc.

man/man8/stacksnoop.8

@@ -10,6 +10,7 @@ calls, and is a quick way to investigate low frequency kernel functions and
 their cause. For high frequency kernel functions, see stackcount.
 
 This tool only works on Linux 4.6+. Stack traces are obtained using the new BPF_STACK_TRACE` APIs.
+For kernels older than 4.6, see the version under tools/old.
 .SH REQUIREMENTS
 CONFIG_BPF and bcc.
 .SH OPTIONS