Re: [PATCH v2 00/14] perf: Stream comparison

[Jiri Olsa]

On Fri, Mar 13, 2020 at 03:11:04PM +0800, Jin Yao wrote:
> Sometimes, a small change in a hot function reducing the cycles of
> this function, but the overall workload doesn't get faster. It is
> interesting where the cycles are moved to.

I'm getting compilation fail:

	  BUILD:   Doing 'make -j1' parallel build
	  CC       util/srclist.o
	util/srclist.c: In function âsrclist__node_newâ:
	util/srclist.c:388:35: error: â%sâ directive output may be truncated writing up to 4095 bytes into a region of size 4091 [-Werror=format-truncation=]
	  388 |  snprintf(cmd, sizeof(cmd), "diff %s %s",
	      |                                   ^~
	......
	  456 |  ret = init_src_info(b_path, a_path, rel_path, &node->info);
	      |                      ~~~~~~        
	In file included from /usr/include/stdio.h:867,
			 from util/srclist.c:8:
	/usr/include/bits/stdio2.h:67:10: note: â__builtin___snprintf_chkâ output between 7 and 8197 bytes into a destination of size 4096
	   67 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
	      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	   68 |        __bos (__s), __fmt, __va_arg_pack ());
	      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	cc1: all warnings being treated as errors
	mv: cannot stat 'util/.srclist.o.tmp': No such file or directory
	make[4]: *** [/home/jolsa/kernel/linux-perf/tools/build/Makefile.build:97: util/srclist.o] Error 1
	make[3]: *** [/home/jolsa/kernel/linux-perf/tools/build/Makefile.build:139: util] Error 2
	make[2]: *** [Makefile.perf:617: perf-in.o] Error 2
	make[1]: *** [Makefile.perf:225: sub-make] Error 2
	make: *** [Makefile:70: all] Error 2


[jolsa@krava ~]$ gcc --version
gcc (GCC) 9.3.1 20200317 (Red Hat 9.3.1-1)

jirka