Ubuntu 16.04.6 LTS

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Problem 1

struct task_struct （include/linux/sched.h:1041）
struct thread_struct （arch/x86/include/asm/processor.h:442）
struct thread_info （arch/x86/include/asm/thread_info.h:25）
unsigned int task_cpu(...) （include/linux/sched.h:2628）
- #define task_thread_info(...) （include/linux/sched.h:2322）
#define smp_processor_id() （include/linux/smp.h:218）

void schedule(void) （kernel/sched/core.c:3052）
void __schedule(void) （kernel/sched/core.c:2955）
void context_switch(...) （kernel/sched/core.c:1984）
#define switch_to(...) （arch/x86/include/asm/switch_to.h:104）
- ~~#define switch_to(...)~~ （include/asm-generic/switch_to.h:25）
struct task_struct* __switch_to(...) （arch/x86/kernel/process_64.c:272）
struct tss_struct （arch/x86/include/asm/processor.h:264）
struct x86_hw_tss （arch/x86/include/asm/processor.h:240）

nvcsw / nivcsw
sleep / usleep / nanosleep
- sleep_for
gettimeofday
task state
assertion 'sd_id12B_randomize(&id) >= 0' failed at ../src/core/dbus.c:668, function bud_on_connection(). Aborting.
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inline assembly
cpu-bound / io-bound

the following makes different results


std::ios_base::sync_with_stdio(false);
// std::cin.tie(nullptr);

TODO analyze the 2 situation in proj3-iobnd (6 situations in total):
- print way:
  - C printf
  - C++ std::cout
  - C++ std::cout (accelerated)
- with many '\n' or flush
  OR stdout to TERMINAL or FILE
- https://stackoverflow.com/questions/1716296/why-does-printf-not-flush-after-the-call-unless-a-newline-is-in-the-format-strin
- https://stackoverflow.com/questions/5229096/does-printf-always-flush-the-buffer-on-encountering-a-newline
time ./bin/proj3-iobnd 2> 1.log > 2.log
vs.
time ./bin/proj3-iobnd 2> 1.log
TODO strace
- https://stackoverflow.com/questions/6604007/how-can-i-get-a-list-of-linux-system-calls-and-number-of-args-they-take-automati
- https://github.com/strace/strace/blob/v4.11/linux/x86_64/syscallent.h
- strace -et=316,317,319 -C ./proj3-cpunum