linux-kernel - [tip: perf/core] perf symbols: Use kmaps(map)->machine when we know its a kernel map

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Date:   Fri, 15 Nov 2019 07:40:15 -0000
From:   "tip-bot2 for Arnaldo Carvalho de Melo" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Adrian Hunter <adrian.hunter@...el.com>,
        Andi Kleen <ak@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>,
        linux-kernel@...r.kernel.org
Subject: [tip: perf/core] perf symbols: Use kmaps(map)->machine when we know
 its a kernel map

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     93fcce96c71931f65c9bb1a0f2303008e6862c97
Gitweb:        https://git.kernel.org/tip/93fcce96c71931f65c9bb1a0f2303008e6862c97
Author:        Arnaldo Carvalho de Melo <acme@...hat.com>
AuthorDate:    Mon, 04 Nov 2019 16:25:11 -03:00
Committer:     Arnaldo Carvalho de Melo <acme@...hat.com>
CommitterDate: Tue, 12 Nov 2019 08:20:53 -03:00

perf symbols: Use kmaps(map)->machine when we know its a kernel map

And then stop using map->groups to achieve that.

To test that that branch is being taken, probe the function that is only
called from there and then run something like 'perf top' in another
xterm:

  # perf probe -x ~/bin/perf machine__map_x86_64_entry_trampolines
  Added new event:
    probe_perf:machine__map_x86_64_entry_trampolines (on machine__map_x86_64_entry_trampolines in /home/acme/bin/perf)

  You can now use it in all perf tools, such as:

  	perf record -e probe_perf:machine__map_x86_64_entry_trampolines -aR sleep 1

  # perf trace -e probe_perf:*
       0.000 bash/10614 probe_perf:machine__map_x86_64_entry_trampolines(__probe_ip: 5224944)
  ^C#

Cc: Adrian Hunter <adrian.hunter@...el.com>
Cc: Andi Kleen <ak@...ux.intel.com>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Namhyung Kim <namhyung@...nel.org>
Link: https://lkml.kernel.org/n/tip-lgrrzdxo2p9liq2keivcg887@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/symbol.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 2764863..88f4cfb 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1588,7 +1588,7 @@ int dso__load(struct dso *dso, struct map *map)
 	char *name;
 	int ret = -1;
 	u_int i;
-	struct machine *machine;
+	struct machine *machine = NULL;
 	char *root_dir = (char *) "";
 	int ss_pos = 0;
 	struct symsrc ss_[2];
@@ -1617,17 +1617,13 @@ int dso__load(struct dso *dso, struct map *map)
 		goto out;
 	}
 
-	if (map->groups)
-		machine = map->groups->machine;
-	else
-		machine = NULL;
-
 	if (dso->kernel) {
 		if (dso->kernel == DSO_TYPE_KERNEL)
 			ret = dso__load_kernel_sym(dso, map);
 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
 			ret = dso__load_guest_kernel_sym(dso, map);
 
+		machine = map__kmaps(map)->machine;
 		if (machine__is(machine, "x86_64"))
 			machine__map_x86_64_entry_trampolines(machine, dso);
 		goto out;
@@ -2027,15 +2023,9 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
 {
 	int err;
 	const char *kallsyms_filename = NULL;
-	struct machine *machine;
+	struct machine *machine = map__kmaps(map)->machine;
 	char path[PATH_MAX];
 
-	if (!map->groups) {
-		pr_debug("Guest kernel map hasn't the point to groups\n");
-		return -1;
-	}
-	machine = map->groups->machine;
-
 	if (machine__is_default_guest(machine)) {
 		/*
 		 * if the user specified a vmlinux filename, use it and only