From 0c4e774fad0202b91dea8d99c04e9bdf2c2c6647 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 17 Apr 2014 19:39:10 +0200 Subject: [PATCH] perf tools: Cache register accesses for unwind processing Caching registers value into an array. Got about 4% speed up of perf_reg_value function for report command processing dwarf unwind stacks. Output from report over 1.5 GB data with DWARF unwind stacks: (TODO fix perf diff) current code: 5.84% perf perf [.] perf_reg_value change: 1.94% perf perf [.] perf_reg_value And little bit of overall speed up: (perf stat -r 5 -e '{cycles,instructions}:u' ...) current code: 310,298,611,754 cycles ( +- 0.33% ) 439,669,689,341 instructions ( +- 0.03% ) 188.656753166 seconds time elapsed ( +- 0.82% ) change: 291,315,329,878 cycles ( +- 0.22% ) 391,763,485,304 instructions ( +- 0.03% ) 180.742249687 seconds time elapsed ( +- 0.64% ) Acked-by: Namhyung Kim Cc: Arnaldo Carvalho de Melo Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jean Pihet Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1401892622-30848-2-git-send-email-jolsa@kernel.org Signed-off-by: Jiri Olsa --- Reading git-format-patch failed