[agent-smith] Reduce cpu and memory consumption #10356
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utam0k
reviewed
May 30, 2022
| if err != nil { | ||
| return false, xerrors.Errorf("cannot read stream head: %w", err) | ||
| } | ||
| in.header = head |
utam0k
reviewed
May 30, 2022
| if err != nil { | ||
| return false, err | ||
| } | ||
| in.rodata = rodata |
utam0k
reviewed
May 30, 2022
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| if len(in.rodata) > 0 { | ||
| rodata = in.rodata |
utam0k
approved these changes
May 30, 2022
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| if len(in.header) > 0 { | ||
| head = in.header |
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| var symbols []string | ||
| if len(in.symbols) > 0 { | ||
| symbols = in.symbols | ||
| } else { | ||
| executable, err := elf.NewFile(in.Reader) | ||
| if err != nil { | ||
| return false, xerrors.Errorf("cannot anaylse ELF file: %w", err) | ||
| } | ||
|
|
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| symbols, err := ExtractELFSymbols(executable) | ||
| if err != nil { | ||
| return false, err | ||
| symbols, err = ExtractELFSymbols(executable) | ||
| if err != nil { | ||
| return false, err | ||
| } | ||
| in.symbols = symbols |
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| symbols := make([]string, len(syms)+len(dynsyms)) | ||
| i := 0 | ||
| for _, s := range syms { | ||
| symbols[i] = s.Name | ||
| i += 1 | ||
| } | ||
|
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| for _, s := range dynsyms { | ||
| symbols = append(symbols, s.Name) | ||
| symbols[i] = s.Name | ||
| i += 1 |
There was a problem hiding this comment.
We know the number of elements, so I allocate the underlying array once instead of appending to the slice which includes resizing i.e. reallocation of the array.
|
@Furisto I'd like to know how you profile the agent-smith? |
https://www.notion.so/gitpod/Profiling-Go-Code-a0de0ddcb34a48ac9ebee7fa4f0faf52 |
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Description
We have cpu and memory spikes in agent-smith, with big contributors being reading the elf data of binaries. This data is reread for every signature that has been defined. With this change we cache the data for the duration of the match phase.
Related Issue(s)
Fixes ##10331
How to test
Profile agent-smith in preview environment
Release Notes