From 3445432b7b24665cf4693fc4794c62d4d768a978 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 7 Aug 2013 14:38:49 +0300 Subject: [PATCH] perf symbols: avoid SyS kernel syscall aliases When removing duplicate symbols, prefer to remove syscall aliases starting with SyS or compat_SyS. A side-effect of that is that it results in slightly improved results for the "vmlinux symtab matches kallsyms" test. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1375875537-4509-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 02718e728d59..ea62ecd191fa 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -87,6 +87,7 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb) { s64 a; s64 b; + size_t na, nb; /* Prefer a symbol with non zero length */ a = syma->end - syma->start; @@ -120,11 +121,21 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb) else if (a > b) return SYMBOL_B; - /* If all else fails, choose the symbol with the longest name */ - if (strlen(syma->name) >= strlen(symb->name)) + /* Choose the symbol with the longest name */ + na = strlen(syma->name); + nb = strlen(symb->name); + if (na > nb) return SYMBOL_A; - else + else if (na < nb) return SYMBOL_B; + + /* Avoid "SyS" kernel syscall aliases */ + if (na >= 3 && !strncmp(syma->name, "SyS", 3)) + return SYMBOL_B; + if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10)) + return SYMBOL_B; + + return SYMBOL_A; } void symbols__fixup_duplicate(struct rb_root *symbols)