From 0ce58bae851dc3728af1c0b83905cd6b4565417a Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 20 May 2013 14:45:42 +0000 Subject: [PATCH] perf: net_dropmonitor: Use bisection in symbol lookup Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- tools/perf/scripts/python/net_dropmonitor.py | 22 ++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/tools/perf/scripts/python/net_dropmonitor.py b/tools/perf/scripts/python/net_dropmonitor.py index 6acdc82ef47f..32fcee05c0f6 100755 --- a/tools/perf/scripts/python/net_dropmonitor.py +++ b/tools/perf/scripts/python/net_dropmonitor.py @@ -40,10 +40,24 @@ def get_kallsyms_table(): def get_sym(sloc): loc = int(sloc) - for symloc, name in kallsyms[::-1]: - if loc >= symloc: - return (name, loc - symloc) - return (None, 0) + + # Invariant: kallsyms[i][0] <= loc for all 0 <= i <= start + # kallsyms[i][0] > loc for all end <= i < len(kallsyms) + start, end = -1, len(kallsyms) + while end != start + 1: + pivot = (start + end) // 2 + if loc < kallsyms[pivot][0]: + end = pivot + else: + start = pivot + + # Now (start == -1 or kallsyms[start][0] <= loc) + # and (start == len(kallsyms) - 1 or loc < kallsyms[start + 1][0]) + if start >= 0: + symloc, name = kallsyms[start] + return (name, loc - symloc) + else: + return (None, 0) def print_drop_table(): print "%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT")