add disclaimer for fairness

README.md

@@ -55,6 +55,8 @@ func main() {
 
 ### Throughput benchmarks
 
+*Disclaimer: This was tested on the busy GitHub runners with 8 CPUs and the results may be very different from your real environment.* [#14][disclaimer]
+
 A Performance result as below. Check github [benchmark][benchmark] action for more results and details.
 <details>
   <summary>go1.22 benchmark on keysize=16, itemsize=1000000, cachesize=50%, concurrency=8</summary>
@@ -897,6 +899,7 @@ For inquiries or support, contact phus.lu@gmail.com or raise github issues.
 [release]: https://github.com/phuslu/lru/tags
 [goreport-img]: https://goreportcard.com/badge/github.com/phuslu/lru
 [goreport]: https://goreportcard.com/report/github.com/phuslu/lru
+[disclaimer]: https://github.com/phuslu/lru/issues/14
 [benchmark]: https://github.com/phuslu/lru/actions/workflows/benchmark.yml
 [memory]: https://github.com/phuslu/lru/actions/workflows/memory.yml
 [gcscan]: https://github.com/phuslu/lru/actions/workflows/gcscan.yml