Re: [PATCH v4] perf: Add layout support for --symfs option

[Namhyung Kim]

On Mon, Mar 09, 2026 at 05:44:12PM +0000, Changbin Du wrote:
> Add support for parsing an optional layout parameter in the --symfs
> command line option. The format is:
> 
>   --symfs <directory[,layout]>
> 
> Where layout can be:
>   - 'hierarchy': matches full path (default)
>   - 'flat': only matches base name
> 
> When debugging symbol files from a copy of the filesystem (e.g., from a
> container or remote machine), the debug files are often stored in a
> flat directory structure with only filenames, not the full original
> paths. In this case, using 'flat' layout allows perf to find debug
> symbols by matching only the filename rather than the full path.
> 
> For example, given a binary path like:
>   /build/output/lib/foo.so
> 
> With 'perf report --symfs /debug/files,flat', perf will look for:
>   /debug/files/foo.so
> 
> Instead of:
>   /debug/files/build/output/lib/foo.so
> 
> This is particularly useful when:
> - Extracting debug files from containers with different directory layouts
> - Working with build systems that flatten directory structures
> 
> Changes:
> - Add symfs_layout_flat field to symbol_conf struct.
> - Parse optional layout in symbol__config_symfs().
> - Modify __symbol__join_symfs() to use basename() when layout
>   is 'flat'.
> - Update documentation in Documentation/ folder.
> 
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxxx>

Applied to perf-tools-next, thanks!

Best regards,
Namhyung