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added debug mode

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Andreas Abel
2019-02-26 19:06:32 +01:00
parent 379bf1b88c
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5 changed files with 34 additions and 6 deletions
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README.md
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@@ -138,7 +138,7 @@ Both `nanoBench.sh` and `kernel-nanoBench.sh` support the following command-line
| `-loop_count <n>` | Number of iterations of the inner loop. If n>0, the code to be benchmarked **must not modify R15**, as this register contains the loop counter. If n=0, the instructions for the loop are omitted; the loop body is then executed once. `[Default: n=0]` |
| `-warm_up_count <n>` | Number of runs of the generated benchmark code sequence (in each invocation of `run(...)`) before the first measurement result gets recorded . This can, for example, be useful for excluding outliers due to cold caches. `[Default: n=5]` |
| `-initial_warm_up_count <n>` | Number of runs of the benchmark code sequence before the first invocation of `run(...)`. This can be useful for benchmarking instructions that require a warm-up period before they can execute at full speed, like [AVX2 instructions on some microarchitectures](https://www.agner.org/optimize/blog/read.php?i=415). `[Default: n=0]` |
| `-avg` | Selects the arithmetic mean (excluding the top and bottom 20% of the values) as the aggregate function. `[This is the default]` |
| `-avg` | Selects the arithmetic mean (excluding the top and bottom 20% of the values) as the aggregate function. `[This is the default]` |
| `-median` | Selects the median as the aggregate function. |
| `-min` | Selects the minimum as the aggregate function. |
| `-basic_mode` | The effect of this option is described in the [Generated Code](#generated-code) section. |
@@ -152,6 +152,7 @@ The following parameters are only supported by `nanoBench.sh`.
| `-cpu <n>` | Pins the measurement thread to CPU n. `[Default: Pin the thread to the CPU it is currently running on.]` |
| `-usr <n>` | If n=1, performance events are counted when the processor is operating at a privilege level greater than 0. `[Default: n=1]` |
| `-os <n>` | If n=1, performance events are counted when the processor is operating at privilege level 0. `[Default: n=0]` |
| `-debug` | Enables the debug mode (see [below](#debug-mode)). |
## Performance Counter Config Files
@@ -164,6 +165,10 @@ The format of the entries in the configuration files is
You can find details on the meanings of the different parts of the entries in chapters 18 and 19 of [Intel's System Programming Guide](https://software.intel.com/sites/default/files/managed/a4/60/325384-sdm-vol-3abcd.pdf).
## Debug Mode
If the debug mode is enabled, the [generated code](#generated-code) contains a breakpoint right before the line `m2 = read_perf_ctrs`, and *nanoBench* is run using *gdb*. This makes it possible to analyze the effect of the code to be benchmarked on registers and on the memory. The command `info all-registers` can, for example, be used to display the current values of all registers.
## Supported Platforms
*nanoBench* should work with all Intel processors supporting architectural performance monitoring version ≥ 3, as well as with AMD Family 17h processors.