Commit 3445432b authored Aug 07, 2013 by Adrian Hunter Committed by Arnaldo Carvalho de Melo Aug 07, 2013

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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-6-git-send-email-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 2bbf03f1

tools/perf/util/symbol.c

+14 −3

Original line number	Diff line number	Diff line
		@@ -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)