The profiler uses `continuation-mark-set->context' to determine the evaluation context for each profiling sample. As I think you know, the context us computed in different ways with different approximations when interpreting bytecode versus running JIT-generated code.
More specifically, a JIT-based context is reported if any JIT-based information is available in the continuation, otherwise the interpreter-based context is reported. When you start Racket with the JIT enabled, there's some JIT-based context surrounding the `parameterize' form, and so it's reported even though the interpreter context is more complete. I can imagine adding ways to select the context more explicitly, such as an extra argument to `continuation-mark-set->context', but I wonder whether `--no-jit' might be the best way to go overall. At Tue, 6 Mar 2012 15:36:23 -0500, Danny Yoo wrote: > I'm noticing some significant difference in the output of the > statistical profiler with regards to the JIT. I wanted to normalize > this effect by creating an environment for dynamic evaluation, hoping > that setting the right parameters would get me the same effect. > > Here's a `run-profiler.rkt` tool I cooked up that is meant to run the > profiler under a non-jitting context: > > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > ;;;;;;;;;;;;;;;;;;; > #lang racket/base > > (require syntax/strip-context) > > (define modname (vector-ref (current-command-line-arguments) 0)) > > (parameterize ([compile-context-preservation-enabled #t] > [compile-enforce-module-constants #f] > [use-compiled-file-paths '()] > [load-on-demand-enabled #f] > [eval-jit-enabled #f]) > (parameterize ([current-namespace (make-base-namespace)]) > (with-syntax ([modname modname]) > (eval (strip-context #'(module anonymous racket/base > (require profile) > (require modname) > (profile > (call-with-continuation-prompt run))))) > (eval (strip-context #'(require 'anonymous)))))) > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > ;;;;;;;;;;;;;;;;;;; > > > > Unfortunately, it doesn't quite work as well as I'd like. When I use > it to evaluate a small test bed, I see the following: > > #################################################################### > $ racket run-profiler.rkt runner.rkt > Profiling results > ----------------- > Total cpu time observed: 4110ms (out of 4596ms) > Number of samples taken: 56 (once every 73ms) > > ====================================================== > Caller > Idx Total Self Name+src Local% > ms(pct) ms(pct) Callee > ====================================================== > [1] 3422(83.3%) 0(0.0%) [running body] ...er-tutorial/run-profiler.rkt:##f > [running body] [3]100.0% > ------------------------------------------------------ > [2] 688(16.7%) 0(0.0%) run ...dyoo/work/profiler-tutorial/runner.rkt:18:0 > my-flatten [4] 100.0% > ------------------------------------------------------ > [running body] [1]100.0% > [3] 3422(83.3%) 3422(83.3%) [running body] anonymous:##f > ------------------------------------------------------ > run [2] 0.0% > my-flatten [4] 100.0% > [4] 688(16.7%) 0(0.0%) my-flatten ...profiler-tutorial/my-flatten.rkt:7:0 > my-flatten [4] 100.0% > my-append [5] 0.0% > ------------------------------------------------------ > my-flatten [4] 100.0% > [5] 688(16.7%) 688(16.7%) my-append .../profiler-tutorial/my-flatten.rkt:4:0 > ------------------------------------------------------ > > #################################################################### > > > Note that a large part of the "self-runtime" is being attributed to > the "running body" of the anonymous module that I'm generating > dynamically. That's not right. When I run racket with the "--no-jit" > option, I get significantly better output: > > > #################################################################### > kui ~/work/profiler-tutorial $ racket --no-jit run-profiler.rkt runner.rkt > Profiling results > ----------------- > Total cpu time observed: 5381ms (out of 6985ms) > Number of samples taken: 38 (once every 142ms) > > ==================================================== > Caller > Idx Total Self Name+src Local% > ms(pct) ms(pct) Callee > ==================================================== > [1] 5381(100.0%) 0(0.0%) run > ...dyoo/work/profiler-tutorial/runner.rkt:18:0 > my-flatten [2]100.0% > ---------------------------------------------------- > run [1] 0.0% > my-flatten [2]100.0% > [2] 5381(100.0%) 0(0.0%) my-flatten > ...profiler-tutorial/my-flatten.rkt:7:0 > my-flatten [2]100.0% > my-append [3] 0.0% > ---------------------------------------------------- > my-flatten [2]100.0% > [3] 5381(100.0%) 5381(100.0%) my-append > .../profiler-tutorial/my-flatten.rkt:4:0 > ---------------------------------------------------- > #################################################################### > > > This result properly attributes time to the function I intended to be > the hotspot. So it looks like when I run the profiler under > "--no-jit", I get better results. However, I'm trying to understand > why the things I'm doing in run-profiler.rkt don't have the same > effect as if I were running "racket --no-jit ...". > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
