| ... | @@ -281,8 +281,8 @@ the `perf` utility to gather and annotate such data, for example: |
... | @@ -281,8 +281,8 @@ the `perf` utility to gather and annotate such data, for example: |
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```wiki
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```wiki
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$ perf record ./fib
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$ perf record ./fib
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1134903170
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1134903170
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[ perf record: Woken up 9 times to write data ]
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[perf record: Woken up 9 times to write data ]
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[ perf record: Captured and wrote 2.027 MB perf.data (~88582 samples) ]
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[perf record: Captured and wrote 2.027 MB perf.data (~88582 samples) ]
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$ perf annotate
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$ perf annotate
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```
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```
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| ... | @@ -329,7 +329,7 @@ Process 1901610 stopped |
... | @@ -329,7 +329,7 @@ Process 1901610 stopped |
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-> 3 fib 1 = 1
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-> 3 fib 1 = 1
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4 fib n = fib (n-1) + fib (n-2)
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4 fib n = fib (n-1) + fib (n-2)
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5 main :: IO ()
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5 main :: IO ()
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6 main = print $ sum [ fib i | i <- [3..20]]
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6 main = print $ sum [fib i | i <- [3..20]]
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(lldb) image lookup -a 0x00000000004056f7 -v
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(lldb) image lookup -a 0x00000000004056f7 -v
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Address: fib[0x00000000004056f7] (fib..text + 10967)
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Address: fib[0x00000000004056f7] (fib..text + 10967)
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Summary: fib`rnf_info + 207 [inlined] c2rw_entry
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Summary: fib`rnf_info + 207 [inlined] c2rw_entry
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| ... | @@ -447,7 +447,7 @@ Performance problems: |
... | @@ -447,7 +447,7 @@ Performance problems: |
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Currently we use `libdw` (part of `elf-utils`) for stack unwinding and DWARF reading. While `libdw` has the advantage of being comprehensive () and widely used (used by `perf`, among others), it only targets ELF platforms. There are a few alternatives that were considered,
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Currently we use `libdw` (part of `elf-utils`) for stack unwinding and DWARF reading. While `libdw` has the advantage of being comprehensive () and widely used (used by `perf`, among others), it only targets ELF platforms. There are a few alternatives that were considered,
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- `libdwarf` ([ https://www.prevanders.net/dwarf.html](https://www.prevanders.net/dwarf.html)): not widely available; questionable upstream maintenance practices
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- `libdwarf` ([https://www.prevanders.net/dwarf.html](https://www.prevanders.net/dwarf.html)): not widely available; questionable upstream maintenance practices
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- `libdw` ([ https://sourceware.org/elfutils/](https://sourceware.org/elfutils/)): widely available and used, offering both unwinding and ELF/DWARF parsing, reasonably active upstream, only supports ELF, poor documentation
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- `libdw` ([https://sourceware.org/elfutils/](https://sourceware.org/elfutils/)): widely available and used, offering both unwinding and ELF/DWARF parsing, reasonably active upstream, only supports ELF, poor documentation
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- `libbacktrace` ([ https://github.com/gcc-mirror/gcc/tree/master/libbacktrace](https://github.com/gcc-mirror/gcc/tree/master/libbacktrace)): Supports ELF and XCOFF, not widely available
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- `libbacktrace` ([https://github.com/gcc-mirror/gcc/tree/master/libbacktrace](https://github.com/gcc-mirror/gcc/tree/master/libbacktrace)): Supports ELF and XCOFF, not widely available
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- `libunwind` ([ http://www.nongnu.org/libunwind/](http://www.nongnu.org/libunwind/)): well documented, also no MachO support |
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- `libunwind` ([http://www.nongnu.org/libunwind/](http://www.nongnu.org/libunwind/)): well documented, also no MachO support |
