clayborg added a comment. Some perf numbers that involve loading a large iOS Application and all of its shared libraries without caching first and then with caching are found below. The "lldb-perf.py" command will start a timer, run any LLDB commands and then stop the timer and print out. Before the first run, I run "sudo purge" to purge the kernel file cache, and then I run one "cold" run with the file caches being empty. Then I run the same thing again with hot file caches. So the first run is always slower.
First run with no cache enabled: $ lldb-perf.py --lldb /Users/gclayton/Documents/src/llvm/main-clean/Release/bin/lldb --command 'file Facebook.app' ------------------------------------------------------------------------ Cold file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 10.961282056 (lldb) quit ------------------------------------------------------------------------ Warm file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 6.4026089829999995 (lldb) quit ------------------------------------------------------------------------ Warm file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 6.43446597 (lldb) quit Second run with caching enabled: $ lldb-perf.py --lldb /Users/gclayton/Documents/src/llvm/main-clean/Release/bin/lldb --command 'settings set symbols.enable-lldb-modules-cache true' --command 'file Facebook.app' ------------------------------------------------------------------------ Cold file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) settings set symbols.enable-lldb-modules-cache true (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 9.102131989 (lldb) quit ------------------------------------------------------------------------ Warm file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) settings set symbols.enable-lldb-modules-cache true (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 4.374525497 (lldb) quit ------------------------------------------------------------------------ Warm file cache run: ------------------------------------------------------------------------ (lldb) script import time; start_time = time.perf_counter() (lldb) settings set symbols.enable-lldb-modules-cache true (lldb) file Facebook.app Current executable set to 'Facebook.app' (x86_64). (lldb) script print(time.perf_counter() - start_time) 4.353001629 (lldb) quit Results from one large project: 20% faster for cold file caches 47% faster for warm file caches Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D113789/new/ https://reviews.llvm.org/D113789 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
