Remove tracing.md
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				| @ -13,9 +13,8 @@ The ovni project implements a fast instrumentation library that records | ||||
| small events (starting at 12 bytes) during the execution of programs to | ||||
| later investigate how the execution happened. | ||||
| 
 | ||||
| <!-- FIXME: Add a index for runtime --> | ||||
| The instrumentation process is split in two stages: | ||||
| [runtime](user/runtime/tracing.md) | ||||
| [runtime](user/runtime/index.md) | ||||
| tracing and [emulation](user/emulation/index.md). | ||||
| 
 | ||||
| During runtime, very short binary events are stored on disk which | ||||
|  | ||||
| @ -4,7 +4,7 @@ Ovni has a model to represent the hardware components as well as the software | ||||
| concepts like threads or processes. Each concept is considered to be a *part*. | ||||
| Here is an example diagram depicting the part hierarchy: | ||||
| 
 | ||||
|  | ||||
|  | ||||
| 
 | ||||
| Notice how a loom can restrict the CPUs of the node to its child processes. | ||||
| 
 | ||||
|  | ||||
| @ -15,14 +15,12 @@ To initialize libovni follow these steps in all threads: | ||||
|    ovni function. It can be called multiple times from any thread, but only one | ||||
|    is required. | ||||
| 
 | ||||
| 2. **Init the process**. Call `ovni_proc_init()` to initialize the process when | ||||
|    a new process begins the execution. It can only be called **once per | ||||
|    process** and it must be called before the thread is initialized. | ||||
| 2. **Init the process**. Call `ovni_proc_init()` to initialize the process. It | ||||
|    can only be called **once per process** and it must be called before the | ||||
|    thread is initialized. | ||||
| 
 | ||||
| 3. **Init the thread**. Call `ovni_thread_init()` when a new thread begins the | ||||
|    execution (including the main process thread after the process is | ||||
|    initialized). Multiple attempts to initialize the thread are ignored with a | ||||
|    warning. | ||||
| 3. **Init the thread**. Call `ovni_thread_init()` to initialize the thread. | ||||
|    Multiple attempts to initialize the same thread are ignored with a warning. | ||||
| 
 | ||||
| The `ovni_proc_init()` arguments are as follows: | ||||
| 
 | ||||
| @ -32,8 +30,8 @@ void ovni_proc_init(int app, const char *loom, int pid); | ||||
| 
 | ||||
| The `app` defines the "appid" of the program, which must be a number >0. This is | ||||
| useful to run multiple processes some of which run the same "app", so you can | ||||
| tell which one is which. The `loom` defines the | ||||
| [loom](../concepts/part-model.md#loom) name and assignes the process to that | ||||
| tell which one is which. The `loom` argument defines the | ||||
| [loom](../concepts/part-model.md#loom) name and maps the process to that | ||||
| loom. It must be compose of the host name, a dot and a suffix. The PID is the | ||||
| one obtained by `getpid(2)`. | ||||
| 
 | ||||
| @ -59,8 +57,8 @@ the thread stream. | ||||
| ## Start the execution | ||||
| 
 | ||||
| The current thread must switch to the "Running" state before any event can be | ||||
| processed by the emulator. Do so by emitting a `OHx` event in the stream with | ||||
| the appropriate payload: | ||||
| processed by the emulator. Do so by emitting a [`OHx` | ||||
| event](../emulation/events.md#OHx) in the stream with the appropriate payload: | ||||
| 
 | ||||
| ```c | ||||
| static void thread_execute(int32_t cpu, int32_t ctid, uint64_t tag) | ||||
|  | ||||
| @ -1,94 +0,0 @@ | ||||
| # Tracing a new program | ||||
| 
 | ||||
| Read carefully this document before using libovni to instrument a new | ||||
| component. There are a few rules you must follow to ensure the runtime | ||||
| trace is correct. | ||||
| 
 | ||||
| ## Trace processes and threads | ||||
| 
 | ||||
| - Call `ovni_version_check()` once before calling any ovni function. | ||||
| 
 | ||||
| - Call `ovni_proc_init()` when a new process begins the execution. | ||||
| 
 | ||||
| - Call `ovni_thread_init()` when a new thread begins the execution | ||||
|   (including the main process thread). | ||||
| 
 | ||||
| - Call `ovni_thread_require()` with the required model version before | ||||
|   emitting events for that model. | ||||
| 
 | ||||
| - Call `ovni_flush()` and `ovni_thread_free()` when it finishes (in that | ||||
|   order). | ||||
| 
 | ||||
| - Call `ovni_proc_fini()` when a process ends, after all threads have | ||||
|   finished. | ||||
| 
 | ||||
| You can use `ovni_ev_emit()` to record a new event. If you need more | ||||
| than 16 bytes of payload, use `ovni_ev_jumbo_emit()`. See the [trace | ||||
| specification](trace_spec.md) for more details. | ||||
| 
 | ||||
| Compile and link with libovni. When you run your program, a new | ||||
| directory ovni will be created in the current directory `$PWD/ovni` | ||||
| which contains the execution trace. | ||||
| 
 | ||||
| You can change the trace directory by defining the `OVNI_TRACEDIR` | ||||
| environment variable. The envar accepts a trace directory name, a | ||||
| relative path to the trace directory, or its absolute path. In the | ||||
| first case, the trace directory will be created in the current | ||||
| directory `$PWD`. | ||||
| 
 | ||||
| ## Rules | ||||
| 
 | ||||
| Follow these rules to avoid losing events: | ||||
| 
 | ||||
| 1. No event may be emitted until the process is initialized with | ||||
| `ovni_proc_init()` and the thread with `ovni_thread_init()`. | ||||
| 
 | ||||
| 2. When a thread ends the execution, it must call `ovni_flush()` to write the | ||||
| events in the buffer to disk. | ||||
| 
 | ||||
| 3. All threads must have flushed its buffers before calling `ovni_proc_fini()`. | ||||
| 
 | ||||
| ## Select a fast directory | ||||
| 
 | ||||
| During the execution of your program, a per-thread buffer is kept where the new | ||||
| events are being recorded. When this buffer is full, it is written to disk and | ||||
| emptied, an operation known as flush. This may take a while depending on the | ||||
| underliying filesystem. | ||||
| 
 | ||||
| Keep in mind that the thread will be blocked until the flush ends, so if your | ||||
| filesystem is slow it would interrupt the execution of your program for a long | ||||
| time. It is advisable to use the fastest filesystem available (see the tmpfs(5) | ||||
| and df(1) manual pages). | ||||
| 
 | ||||
| You can select the trace directory where the buffers will be flushed during the | ||||
| execution by setting the environment variable `OVNI_TMPDIR`. The last directory | ||||
| will be created if doesn't exist. In that case, as soon as a process calls | ||||
| `ovni_proc_fini()`, the traces of all its threads will be moved to the final | ||||
| directory at `$PWD/ovni`. Example: | ||||
| 
 | ||||
| 	OVNI_TMPDIR=$(mktemp -u /dev/shm/ovni.XXXXXX) srun ./your-app | ||||
| 
 | ||||
| To test the different filesystem speeds, you can use hyperfine and dd. Take a | ||||
| closer look at the max time: | ||||
| 
 | ||||
| ``` | ||||
| $ hyperfine 'dd if=/dev/zero of=/gpfs/projects/bsc15/bsc15557/kk bs=2M count=10' | ||||
| Benchmark 1: dd if=/dev/zero of=/gpfs/projects/bsc15/bsc15557/kk bs=2M count=10 | ||||
|   Time (mean ± σ):      71.7 ms ± 130.4 ms    [User: 0.8 ms, System: 10.2 ms] | ||||
|   Range (min … max):    14.7 ms … 1113.2 ms    162 runs | ||||
|   | ||||
|   Warning: Statistical outliers were detected. Consider re-running this | ||||
|   benchmark on a quiet PC without any interferences from other programs. It | ||||
|   might help to use the '--warmup' or '--prepare' options. | ||||
| 
 | ||||
| $ hyperfine 'dd if=/dev/zero of=/tmp/kk bs=2M count=10' | ||||
| Benchmark 1: dd if=/dev/zero of=/tmp/kk bs=2M count=10 | ||||
|   Time (mean ± σ):      56.2 ms ±   5.7 ms    [User: 0.6 ms, System: 14.8 ms] | ||||
|   Range (min … max):    45.8 ms …  77.8 ms    63 runs | ||||
|   | ||||
| $ hyperfine 'dd if=/dev/zero of=/dev/shm/kk bs=2M count=10' | ||||
| Benchmark 1: dd if=/dev/zero of=/dev/shm/kk bs=2M count=10 | ||||
|   Time (mean ± σ):      11.4 ms ±   0.4 ms    [User: 0.5 ms, System: 11.1 ms] | ||||
|   Range (min … max):     9.7 ms …  12.5 ms    269 runs | ||||
| ``` | ||||
| 
 | ||||
| @ -29,7 +29,6 @@ nav: | ||||
|       - user/concepts/trace-model.md | ||||
|     - 'Runtime': | ||||
|       - user/runtime/index.md | ||||
|       - user/runtime/tracing.md | ||||
|       - user/runtime/mark.md | ||||
|       - user/runtime/distributed.md | ||||
|       - user/runtime/kernel.md | ||||
|  | ||||
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