[llvm] [BOLT][docs] Add merge-fdata to Linux optimization guide (PR #97659)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-bolt

Author: Maksim Panchenko (maksfb)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/97659.diff


1 Files Affected:

- (modified) bolt/docs/OptimizingLinux.md (+5) 


``````````diff
diff --git a/bolt/docs/OptimizingLinux.md b/bolt/docs/OptimizingLinux.md
index 1fffcf2252906..0045f0ead9fd0 100644
--- a/bolt/docs/OptimizingLinux.md
+++ b/bolt/docs/OptimizingLinux.md
@@ -44,6 +44,11 @@ $ perf2bolt -p perf.data -o perf.fdata vmlinux
 
 Under a high load, `perf.data` should be several gigabytes in size and you should expect the converted `perf.fdata` not to exceed 100 MB.
 
+Profiles collected from multiple workloads could be joined into a single profile using `merge-fdata` utility:
+```bash
+$ merge-fdata perf.1.fdata perf.2.fdata ... perf.<N>.fdata > perf.merged.fdata
+```
+
 Two changes are required for the kernel build. The first one is optional but highly recommended. It introduces a BOLT-reserved space into `vmlinux` code section:
 
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/97659