From 7d5eaba9b33682b734e3a79c21c4a9a5f91624b1 Mon Sep 17 00:00:00 2001 From: He Kuang Date: Mon, 11 May 2015 09:25:04 +0000 Subject: [PATCH] perf probe: Show better error message when failed to find variable Indicate to check variable location range in error message when we got failed to find the variable. Before this patch: $ perf probe --add 'generic_perform_write+118 bytes' Failed to find the location of bytes at this address. Perhaps, it has been optimized out. Error: Failed to add events. After this patch: $ perf probe --add 'generic_perform_write+118 bytes' Failed to find the location of the 'bytes' variable at this address. Perhaps it has been optimized out. Use -V with the --range option to show 'bytes' location range. Error: Failed to add events. Signed-off-by: He Kuang Acked-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1431336304-16863-3-git-send-email-hekuang@huawei.com [ Improve the error message based on lkml thread ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 5804086425aa..590a24a7f555 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -527,10 +527,12 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, &pf->sp_die, pf->tvar); - if (ret == -ENOENT || ret == -EINVAL) - pr_err("Failed to find the location of %s at this address.\n" - " Perhaps, it has been optimized out.\n", pf->pvar->var); - else if (ret == -ENOTSUP) + if (ret == -ENOENT || ret == -EINVAL) { + pr_err("Failed to find the location of the '%s' variable at this address.\n" + " Perhaps it has been optimized out.\n" + " Use -V with the --range option to show '%s' location range.\n", + pf->pvar->var, pf->pvar->var); + } else if (ret == -ENOTSUP) pr_err("Sorry, we don't support this variable location yet.\n"); else if (ret == 0 && pf->pvar->field) { ret = convert_variable_fields(vr_die, pf->pvar->var, -- 2.20.1