Re: [PATCH 4/4] perf tools: Fallback to srcdir/Documentation/tips.txt

From: Arnaldo Carvalho de Melo
Date: Tue Jan 12 2016 - 10:23:08 EST


Em Sat, Jan 09, 2016 at 07:16:29PM +0900, Namhyung Kim escreveu:
> Some people don't install perf, but just use compiled version in the
> source. Fallback to lookup the source directory for those poor guys. :)
>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>

So, after applying this I tried:

$ rm -f ~/share/doc/perf-tip/tips.txt

To make it fallback and:

$ perf report --stdio | tail -3
#
# (Tip: get more memory! ;-p)
#
$

Doesn't work, looking at what it is trying to find:

# perf trace --no-inherit -e access perf report --stdio
0.090 ( 0.010 ms): access(filename: /etc/ld.so.preload, mode: R ) = -1 ENOENT No such file or directory
2.013 ( 0.014 ms): access(filename: /home/acme/etc/perfconfig, mode: R ) = -1 ENOENT No such file or directory
2.045 ( 0.004 ms): access(filename: /home/acme/etc/perfconfig, mode: R ) = -1 ENOENT No such file or directory
2.076 ( 0.005 ms): access(filename: /home/acme/etc/perfconfig, mode: R ) = -1 ENOENT No such file or directory
2.239 ( 0.006 ms): access(filename: /usr/bin/pager, mode: X ) = -1 ENOENT No such file or directory
2.244 ( 0.004 ms): access(filename: /usr/bin/less, mode: X ) = 0
16.969 ( 0.018 ms): access(filename: /home/acme/share/doc/perf-tip/tips.txt ) = -1 ENOENT No such file or directory
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 5 of event 'cycles:pp'
# Event count (approx.): 24954605
#
# Overhead Command Shared Object Symbol
# ........ ....... ................ .........................
#
99.68% usleep [kernel.vmlinux] [k] vma_rb_erase
0.32% perf [kernel.vmlinux] [k] nmi_cpu_backtrace
0.00% perf [kernel.vmlinux] [k] native_write_msr_safe

#
# (Tip: get more memory! ;-p)
#
#


Also you're not just fallbacking, you did this other unrelated change, no?

- const char *help = perf_tip(TIPDIR);
+ const char *help = perf_tip(system_path(TIPDIR));


Investigating...

> ---
> tools/perf/builtin-report.c | 10 +++++++++-
> tools/perf/util/util.c | 11 ++++++-----
> 2 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index d5a42ee12529..2bf537f190a0 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -28,6 +28,7 @@
> #include "util/tool.h"
>
> #include <subcmd/parse-options.h>
> +#include <subcmd/exec-cmd.h>
> #include "util/parse-events.h"
>
> #include "util/thread.h"
> @@ -433,7 +434,14 @@ static int report__browse_hists(struct report *rep)
> int ret;
> struct perf_session *session = rep->session;
> struct perf_evlist *evlist = session->evlist;
> - const char *help = perf_tip(TIPDIR);
> + const char *help = perf_tip(system_path(TIPDIR));
> +
> + if (help == NULL) {
> + /* fallback for people who don't install perf ;-) */
> + help = perf_tip(DOCDIR);
> + if (help == NULL)
> + help = "Cannot load tips.txt file, please install perf!";
> + }
>
> switch (use_browser) {
> case 1:
> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> index 88b8f8d21f58..92e8543dadf9 100644
> --- a/tools/perf/util/util.c
> +++ b/tools/perf/util/util.c
> @@ -17,7 +17,6 @@
> #include <unistd.h>
> #include "callchain.h"
> #include "strlist.h"
> -#include <subcmd/exec-cmd.h>
>
> struct callchain_param callchain_param = {
> .mode = CHAIN_GRAPH_ABS,
> @@ -672,14 +671,16 @@ const char *perf_tip(const char *dirpath)
> struct str_node *node;
> char *tip = NULL;
> struct strlist_config conf = {
> - .dirname = system_path(dirpath) ,
> + .dirname = dirpath,
> + .file_only = true,
> };
>
> tips = strlist__new("tips.txt", &conf);
> - if (tips == NULL || strlist__nr_entries(tips) == 1) {
> - tip = (char *)"Cannot find tips.txt file";
> + if (tips == NULL)
> + return "Tip: get more memory! ;-p";
> +
> + if (strlist__nr_entries(tips) == 0)
> goto out;
> - }
>
> node = strlist__entry(tips, random() % strlist__nr_entries(tips));
> if (asprintf(&tip, "Tip: %s", node->s) < 0)
> --
> 2.6.4