Hardware Profile

gistfile1.txt

% hhvm -g --hdf Eval.ProfileHWEnable=true test.php
:
:
Breakpoint 7, HPHP::HardwareCounter::HardwareCounter (this=0x7fffee224dc0)
    at hphp/runtime/base/hardware-counter.cpp:182
182	  : m_countersSet(false) {
(gdb) p RuntimeOption::EvalProfileHWEnable
$2 = true

----

hhvm -g --hdf Eval.ProfileHWEnable=false test.php

Breakpoint 6, HPHP::HardwareCounter::HardwareCounter (this=0x7fffee224dc0)
    at hphp/runtime/base/hardware-counter.cpp:182
182	  : m_countersSet(false) {
(gdb) p RuntimeOption::EvalProfileHWEnable
$1 = false

-----

and hphp_process_init() which starts looking at hardware counters is done *after* the RuntimeOptions are bound.

(gdb) bt
#0  HPHP::HardwareCounter::HardwareCounter (this=0x7fffee224dc0)
    at hphp/runtime/base/hardware-counter.cpp:182
#1  0x0000000008768b1b in HPHP::ThreadLocalNoCheck<HPHP::HardwareCounter>::create (
    this=0x7ffff7fe91e8) at hphp/util/thread-local.h:252
#2  0x000000000876889c in HPHP::ThreadLocalNoCheck<HPHP::HardwareCounter>::getCheck (
    this=0x7ffff7fe91e8) at hphp/util/thread-local.h:257
#3  0x00000000087686f1 in HPHP::init_thread_locals (arg=0x0)
    at hphp/runtime/base/thread-init-fini.cpp:66
#4  0x00000000087c59f8 in HPHP::hphp_process_init ()
    at hphp/runtime/base/program-functions.cpp:1632
#5  0x00000000087c4065 in HPHP::execute_program_impl (argc=18, argv=0x7fffffffd8c8)
    at hphp/runtime/base/program-functions.cpp:1431
#6  0x00000000087c11b7 in HPHP::execute_program (argc=18, argv=0x7fffffffd8c8)
    at hphp/runtime/base/program-functions.cpp:941
---Type <return> to continue, or q <return> to quit---
#7  0x0000000007373e03 in main (argc=18, argv=0x7fffffffd8c8) at hphp/hhvm/main.cpp:61