add small notes to pprof section

TODO

@@ -81,7 +81,6 @@ cgo:
     https://www.youtube.com/watch?v=lhMhApWQp2E : cgo gophercon
     cgo performance tracking bug: https://github.com/golang/go/issues/9704
 
-
 videos:
     https://gophervids.appspot.com/#tags=optimization
         -- figure out which of these are specifically worth listing
@@ -191,7 +190,6 @@ papers:
     https://www.akkadia.org/drepper/cpumemory.pdf
     https://software.intel.com/sites/default/files/article/392271/aos-to-soa-optimizations-using-iterative-closest-point-mini-app.pdf
 
-
 optimization guides:
     http://developer.amd.com/resources/developer-guides-manuals/
     http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.uan0015b/index.html

performance.md

@@ -902,17 +902,19 @@ More importantly, it also tells you when to stop. Pretty much all optimizations
 add code complexity in exchange for speed. And you can *always* make code
 faster. It's a balancing act.
 
-TODO(dgryski): How much of this is superfluous given Dave's workshop?
-
 ## Tooling
 
 ### Introductory Profiling
 
-Techniques applicable to source code in general
+This is a quick cheat-sheet for using the pprof tooling.  There are plenty of other guides available on this.
+Check out https://github.com/davecheney/high-performance-go-workshop.
+
+TODO(dgryski): videos?
 
 1. Introduction to pprof
    * go tool pprof (and <https://github.com/google/pprof>)
 1. Writing and running (micro)benchmarks
+   * small, like unit tests
    * profile, extract hot code to benchmark, optimize benchmark, profile.
    * -cpuprofile / -memprofile / -benchmem
    * 0.5 ns/op means it was optimized away -> how to avoid
@@ -922,7 +924,9 @@ Techniques applicable to source code in general
   * malloc, gc workers
   * runtime.\_ExternalCode
 1. Macro-benchmarks (Profiling in production)
-   * net/http/pprof
+   * larger, like end-to-end tests
+   * net/http/pprof, debug muxer
+   * because it's sampling, hitting 10 servers at 100hz is the same as hitting 1 server at 1000hz
 1. Using -base to look at differences
 1. Memory options: -inuse_space, -inuse_objects, -alloc_space, -alloc_objects
 1. Profiling in production; localhost+ssh tunnels, auth headers, using curl.