29 files changed, 433 insertions, 102 deletions

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 5c1867a13ef2..4d885934b919 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4828,6 +4828,7 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
                         case 'z':
                         case 'Z':
                         case '0' ... '9':
+                        case '-':
                                 goto cont_process;
                         case 'p':
                                 if (pevent->long_size == 4)
diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index c0d24791a7f3..614b2c7b0293 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -226,6 +226,13 @@ OPTIONS
         Display context switch events i.e. events of type PERF_RECORD_SWITCH or
         PERF_RECORD_SWITCH_CPU_WIDE.
 
+--demangle::
+        Demangle symbol names to human readable form. It's enabled by default,
+        disable with --no-demangle.
+
+--demangle-kernel::
+        Demangle kernel symbol names to human readable form (for C++ kernels).
+
 --header
         Show perf.data header.
 
diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
index b7bb42c44694..b00dfd92ea73 100644
--- a/tools/perf/arch/common.c
+++ b/tools/perf/arch/common.c
@@ -128,7 +128,7 @@ static const char *normalize_arch(char *arch)
         return arch;
 }
 
-static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
+static int perf_session_env__lookup_binutils_path(struct perf_env *env,
                                                   const char *name,
                                                   const char **path)
 {
@@ -206,7 +206,7 @@ out_error:
         return -1;
 }
 
-int perf_session_env__lookup_objdump(struct perf_session_env *env)
+int perf_session_env__lookup_objdump(struct perf_env *env)
 {
         /*
          * For live mode, env->arch will be NULL and we can use
diff --git a/tools/perf/arch/common.h b/tools/perf/arch/common.h
index ede246eda9be..20176df69fc8 100644
--- a/tools/perf/arch/common.h
+++ b/tools/perf/arch/common.h
@@ -5,6 +5,6 @@
 
 extern const char *objdump_path;
 
-int perf_session_env__lookup_objdump(struct perf_session_env *env);
+int perf_session_env__lookup_objdump(struct perf_env *env);
 
 #endif /* ARCH_PERF_COMMON_H */
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index 65b4835309c7..7b8450cd33c2 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -25,8 +25,6 @@
 static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
 {
         char root_dir[PATH_MAX];
-        char notes[PATH_MAX];
-        u8 build_id[BUILD_ID_SIZE];
         char *p;
 
         strlcpy(root_dir, proc_dir, sizeof(root_dir));
@@ -35,15 +33,7 @@ static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
         if (!p)
                 return -1;
         *p = '\0';
-
-        scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
-
-        if (sysfs__read_build_id(notes, build_id, sizeof(build_id)))
-                return -1;
-
-        build_id__sprintf(build_id, sizeof(build_id), sbuildid);
-
-        return 0;
+        return sysfs__sprintf_build_id(root_dir, sbuildid);
 }
 
 static int build_id_cache__kcore_dir(char *dir, size_t sz)
@@ -138,7 +128,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
                 return -1;
         *p = '\0';
 
-        if (build_id_cache__kcore_buildid(from_dir, sbuildid))
+        if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
                 return -1;
 
         scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s",
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index b5ca988ebfbe..918b4de29de4 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -19,29 +19,25 @@
 
 static int sysfs__fprintf_build_id(FILE *fp)
 {
-        u8 kallsyms_build_id[BUILD_ID_SIZE];
         char sbuild_id[SBUILD_ID_SIZE];
+        int ret;
 
-        if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
-                                 sizeof(kallsyms_build_id)) != 0)
-                return -1;
+        ret = sysfs__sprintf_build_id("/", sbuild_id);
+        if (ret != sizeof(sbuild_id))
+                return ret < 0 ? ret : -EINVAL;
 
-        build_id__sprintf(kallsyms_build_id, sizeof(kallsyms_build_id),
-                          sbuild_id);
-        fprintf(fp, "%s\n", sbuild_id);
-        return 0;
+        return fprintf(fp, "%s\n", sbuild_id);
 }
 
 static int filename__fprintf_build_id(const char *name, FILE *fp)
 {
-        u8 build_id[BUILD_ID_SIZE];
         char sbuild_id[SBUILD_ID_SIZE];
+        int ret;
 
-        if (filename__read_build_id(name, build_id,
-                                    sizeof(build_id)) != sizeof(build_id))
-                return 0;
+        ret = filename__sprintf_build_id(name, sbuild_id);
+        if (ret != sizeof(sbuild_id))
+                return ret < 0 ? ret : -EINVAL;
 
-        build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
         return fprintf(fp, "%s\n", sbuild_id);
 }
 
@@ -63,7 +59,7 @@ static int perf_session__list_build_ids(bool force, bool with_hits)
         /*
          * See if this is an ELF file first:
          */
-        if (filename__fprintf_build_id(input_name, stdout))
+        if (filename__fprintf_build_id(input_name, stdout) > 0)
                 goto out;
 
         session = perf_session__new(&file, false, &build_id__mark_dso_hit_ops);
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 105332e950a9..4430340292c0 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1671,6 +1671,11 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
                             itrace_parse_synth_opts),
         OPT_BOOLEAN(0, "full-source-path", &srcline_full_filename,
                         "Show full source file name path for source lines"),
+        OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
+                        "Enable symbol demangling"),
+        OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+                        "Enable kernel symbol demangling"),
+
         OPT_END()
         };
         const char * const script_subcommands[] = { "record", "report", NULL };
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 2f1162daa3c5..4e3abba03062 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1,3 +1,21 @@
+/*
+ * builtin-trace.c
+ *
+ * Builtin 'trace' command:
+ *
+ * Display a continuously updated trace of any workload, CPU, specific PID,
+ * system wide, etc.  Default format is loosely strace like, but any other
+ * event may be specified using --event.
+ *
+ * Copyright (C) 2012, 2013, 2014, 2015 Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Initially based on the 'trace' prototype by Thomas Gleixner:
+ *
+ * http://lwn.net/Articles/415728/ ("Announcing a new utility: 'trace'")
+ *
+ * Released under the GPL v2. (and only v2, not any later version)
+ */
+
 #include <traceevent/event-parse.h>
 #include "builtin.h"
 #include "util/color.h"
@@ -27,6 +45,7 @@
 
 #ifndef MADV_HWPOISON
 # define MADV_HWPOISON          100
+
 #endif
 
 #ifndef MADV_MERGEABLE
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index b857fcbd00cf..07dbff5c0e60 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -231,7 +231,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
                         (*argc)--;
                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
                         perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
-                        fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
+                        fprintf(stderr, "dir: %s\n", tracing_path);
                         if (envchanged)
                                 *envchanged = 1;
                 } else if (!strcmp(cmd, "--list-cmds")) {
diff --git a/tools/perf/scripts/python/bin/compaction-times-record b/tools/perf/scripts/python/bin/compaction-times-record
new file mode 100644
index 000000000000..6edcd40e14e8
--- /dev/null
+++ b/tools/perf/scripts/python/bin/compaction-times-record
@@ -0,0 +1,2 @@
+#!/bin/bash
+perf record -e compaction:mm_compaction_begin -e compaction:mm_compaction_end -e compaction:mm_compaction_migratepages -e compaction:mm_compaction_isolate_migratepages -e compaction:mm_compaction_isolate_freepages $@
diff --git a/tools/perf/scripts/python/bin/compaction-times-report b/tools/perf/scripts/python/bin/compaction-times-report
new file mode 100644
index 000000000000..3dc13897cfde
--- /dev/null
+++ b/tools/perf/scripts/python/bin/compaction-times-report
@@ -0,0 +1,4 @@
+#!/bin/bash
+#description: display time taken by mm compaction
+#args: [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex]
+perf script -s "$PERF_EXEC_PATH"/scripts/python/compaction-times.py $@
diff --git a/tools/perf/scripts/python/compaction-times.py b/tools/perf/scripts/python/compaction-times.py
new file mode 100644
index 000000000000..239cb0568ec3
--- /dev/null
+++ b/tools/perf/scripts/python/compaction-times.py
@@ -0,0 +1,311 @@
+# report time spent in compaction
+# Licensed under the terms of the GNU GPL License version 2
+
+# testing:
+# 'echo 1 > /proc/sys/vm/compact_memory' to force compaction of all zones
+
+import os
+import sys
+import re
+
+import signal
+signal.signal(signal.SIGPIPE, signal.SIG_DFL)
+
+usage = "usage: perf script report compaction-times.py -- [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex]\n"
+
+class popt:
+        DISP_DFL = 0
+        DISP_PROC = 1
+        DISP_PROC_VERBOSE=2
+
+class topt:
+        DISP_TIME = 0
+        DISP_MIG = 1
+        DISP_ISOLFREE = 2
+        DISP_ISOLMIG = 4
+        DISP_ALL = 7
+
+class comm_filter:
+        def __init__(self, re):
+                self.re = re
+
+        def filter(self, pid, comm):
+                m = self.re.search(comm)
+                return m == None or m.group() == ""
+
+class pid_filter:
+        def __init__(self, low, high):
+                self.low = (0 if low == "" else int(low))
+                self.high = (0 if high == "" else int(high))
+
+        def filter(self, pid, comm):
+                return not (pid >= self.low and (self.high == 0 or pid <= self.high))
+
+def set_type(t):
+        global opt_disp
+        opt_disp = (t if opt_disp == topt.DISP_ALL else opt_disp|t)
+
+def ns(sec, nsec):
+        return (sec * 1000000000) + nsec
+
+def time(ns):
+        return "%dns" % ns if opt_ns else "%dus" % (round(ns, -3) / 1000)
+
+class pair:
+        def __init__(self, aval, bval, alabel = None, blabel = None):
+                self.alabel = alabel
+                self.blabel = blabel
+                self.aval = aval
+                self.bval = bval
+
+        def __add__(self, rhs):
+                self.aval += rhs.aval
+                self.bval += rhs.bval
+                return self
+
+        def __str__(self):
+                return "%s=%d %s=%d" % (self.alabel, self.aval, self.blabel, self.bval)
+
+class cnode:
+        def __init__(self, ns):
+                self.ns = ns
+                self.migrated = pair(0, 0, "moved", "failed")
+                self.fscan = pair(0,0, "scanned", "isolated")
+                self.mscan = pair(0,0, "scanned", "isolated")
+
+        def __add__(self, rhs):
+                self.ns += rhs.ns
+                self.migrated += rhs.migrated
+                self.fscan += rhs.fscan
+                self.mscan += rhs.mscan
+                return self
+
+        def __str__(self):
+                prev = 0
+                s = "%s " % time(self.ns)
+                if (opt_disp & topt.DISP_MIG):
+                        s += "migration: %s" % self.migrated
+                        prev = 1
+                if (opt_disp & topt.DISP_ISOLFREE):
+                        s += "%sfree_scanner: %s" % (" " if prev else "", self.fscan)
+                        prev = 1
+                if (opt_disp & topt.DISP_ISOLMIG):
+                        s += "%smigration_scanner: %s" % (" " if prev else "", self.mscan)
+                return s
+
+        def complete(self, secs, nsecs):
+                self.ns = ns(secs, nsecs) - self.ns
+
+        def increment(self, migrated, fscan, mscan):
+                if (migrated != None):
+                        self.migrated += migrated
+                if (fscan != None):
+                        self.fscan += fscan
+                if (mscan != None):
+                        self.mscan += mscan
+
+
+class chead:
+        heads = {}
+        val = cnode(0);
+        fobj = None
+
+        @classmethod
+        def add_filter(cls, filter):
+                cls.fobj = filter
+
+        @classmethod
+        def create_pending(cls, pid, comm, start_secs, start_nsecs):
+                filtered = 0
+                try:
+                        head = cls.heads[pid]
+                        filtered = head.is_filtered()
+                except KeyError:
+                        if cls.fobj != None:
+                                filtered = cls.fobj.filter(pid, comm)
+                        head = cls.heads[pid] = chead(comm, pid, filtered)
+
+                if not filtered:
+                        head.mark_pending(start_secs, start_nsecs)
+
+        @classmethod
+        def increment_pending(cls, pid, migrated, fscan, mscan):
+                head = cls.heads[pid]
+                if not head.is_filtered():
+                        if head.is_pending():
+                                head.do_increment(migrated, fscan, mscan)
+                        else:
+                                sys.stderr.write("missing start compaction event for pid %d\n" % pid)
+
+        @classmethod
+        def complete_pending(cls, pid, secs, nsecs):
+                head = cls.heads[pid]
+                if not head.is_filtered():
+                        if head.is_pending():
+                                head.make_complete(secs, nsecs)
+                        else:
+                                sys.stderr.write("missing start compaction event for pid %d\n" % pid)
+
+        @classmethod
+        def gen(cls):
+                if opt_proc != popt.DISP_DFL:
+                        for i in cls.heads:
+                                yield cls.heads[i]
+
+        @classmethod
+        def str(cls):
+                return cls.val
+
+        def __init__(self, comm, pid, filtered):
+                self.comm = comm
+                self.pid = pid
+                self.val = cnode(0)
+                self.pending = None
+                self.filtered = filtered
+                self.list = []
+
+        def __add__(self, rhs):
+                self.ns += rhs.ns
+                self.val += rhs.val
+                return self
+
+        def mark_pending(self, secs, nsecs):
+                self.pending = cnode(ns(secs, nsecs))
+
+        def do_increment(self, migrated, fscan, mscan):
+                self.pending.increment(migrated, fscan, mscan)
+
+        def make_complete(self, secs, nsecs):
+                self.pending.complete(secs, nsecs)
+                chead.val += self.pending
+
+                if opt_proc != popt.DISP_DFL:
+                        self.val += self.pending
+
+                        if opt_proc == popt.DISP_PROC_VERBOSE:
+                                self.list.append(self.pending)
+                self.pending = None
+
+        def enumerate(self):
+                if opt_proc == popt.DISP_PROC_VERBOSE and not self.is_filtered():
+                        for i, pelem in enumerate(self.list):
+                                sys.stdout.write("%d[%s].%d: %s\n" % (self.pid, self.comm, i+1, pelem))
+
+        def is_pending(self):
+                return self.pending != None
+
+        def is_filtered(self):
+                return self.filtered
+
+        def display(self):
+                if not self.is_filtered():
+                        sys.stdout.write("%d[%s]: %s\n" % (self.pid, self.comm, self.val))
+
+
+def trace_end():
+        sys.stdout.write("total: %s\n" % chead.str())
+        for i in chead.gen():
+                i.display(),
+                i.enumerate()
+
+def compaction__mm_compaction_migratepages(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, nr_migrated, nr_failed):
+
+        chead.increment_pending(common_pid,
+                pair(nr_migrated, nr_failed), None, None)
+
+def compaction__mm_compaction_isolate_freepages(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, start_pfn, end_pfn, nr_scanned, nr_taken):
+
+        chead.increment_pending(common_pid,
+                None, pair(nr_scanned, nr_taken), None)
+
+def compaction__mm_compaction_isolate_migratepages(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, start_pfn, end_pfn, nr_scanned, nr_taken):
+
+        chead.increment_pending(common_pid,
+                None, None, pair(nr_scanned, nr_taken))
+
+def compaction__mm_compaction_end(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, zone_start, migrate_start, free_start, zone_end,
+        sync, status):
+
+        chead.complete_pending(common_pid, common_secs, common_nsecs)
+
+def compaction__mm_compaction_begin(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, zone_start, migrate_start, free_start, zone_end,
+        sync):
+
+        chead.create_pending(common_pid, common_comm, common_secs, common_nsecs)
+
+def pr_help():
+        global usage
+
+        sys.stdout.write(usage)
+        sys.stdout.write("\n")
+        sys.stdout.write("-h    display this help\n")
+        sys.stdout.write("-p    display by process\n")
+        sys.stdout.write("-pv   display by process (verbose)\n")
+        sys.stdout.write("-t    display stall times only\n")
+        sys.stdout.write("-m    display stats for migration\n")
+        sys.stdout.write("-fs   display stats for free scanner\n")
+        sys.stdout.write("-ms   display stats for migration scanner\n")
+        sys.stdout.write("-u    display results in microseconds (default nanoseconds)\n")
+
+
+comm_re = None
+pid_re = None
+pid_regex = "^(\d*)-(\d*)$|^(\d*)$"
+
+opt_proc = popt.DISP_DFL
+opt_disp = topt.DISP_ALL
+
+opt_ns = True
+
+argc = len(sys.argv) - 1
+if argc >= 1:
+        pid_re = re.compile(pid_regex)
+
+        for i, opt in enumerate(sys.argv[1:]):
+                if opt[0] == "-":
+                        if opt == "-h":
+                                pr_help()
+                                exit(0);
+                        elif opt == "-p":
+                                opt_proc = popt.DISP_PROC
+                        elif opt == "-pv":
+                                opt_proc = popt.DISP_PROC_VERBOSE
+                        elif opt == '-u':
+                                opt_ns = False
+                        elif opt == "-t":
+                                set_type(topt.DISP_TIME)
+                        elif opt == "-m":
+                                set_type(topt.DISP_MIG)
+                        elif opt == "-fs":
+                                set_type(topt.DISP_ISOLFREE)
+                        elif opt == "-ms":
+                                set_type(topt.DISP_ISOLMIG)
+                        else:
+                                sys.exit(usage)
+
+                elif i == argc - 1:
+                        m = pid_re.search(opt)
+                        if m != None and m.group() != "":
+                                if m.group(3) != None:
+                                        f = pid_filter(m.group(3), m.group(3))
+                                else:
+                                        f = pid_filter(m.group(1), m.group(2))
+                        else:
+                                try:
+                                        comm_re=re.compile(opt)
+                                except:
+                                        sys.stderr.write("invalid regex '%s'" % opt)
+                                        sys.exit(usage)
+                                f = comm_filter(comm_re)
+
+                        chead.add_filter(f)
diff --git a/tools/perf/ui/browser.h b/tools/perf/ui/browser.h
index 52be87125def..f3cef564de02 100644
--- a/tools/perf/ui/browser.h
+++ b/tools/perf/ui/browser.h
@@ -61,8 +61,8 @@ int ui_browser__help_window(struct ui_browser *browser, const char *text);
 bool ui_browser__dialog_yesno(struct ui_browser *browser, const char *text);
 int ui_browser__input_window(const char *title, const char *text, char *input,
                              const char *exit_msg, int delay_sec);
-struct perf_session_env;
-int tui__header_window(struct perf_session_env *env);
+struct perf_env;
+int tui__header_window(struct perf_env *env);
 
 void ui_browser__argv_seek(struct ui_browser *browser, off_t offset, int whence);
 unsigned int ui_browser__argv_refresh(struct ui_browser *browser);
diff --git a/tools/perf/ui/browsers/header.c b/tools/perf/ui/browsers/header.c
index f10681717f93..edbeaaf31ace 100644
--- a/tools/perf/ui/browsers/header.c
+++ b/tools/perf/ui/browsers/header.c
@@ -91,7 +91,7 @@ static int ui__list_menu(int argc, char * const argv[])
         return list_menu__run(&menu);
 }
 
-int tui__header_window(struct perf_session_env *env)
+int tui__header_window(struct perf_env *env)
 {
         int i, argc = 0;
         char **argv;
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 10c7ec041039..cf86f2d3a5e7 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -26,7 +26,7 @@ struct hist_browser {
         struct map_symbol   *selection;
         struct hist_browser_timer *hbt;
         struct pstack       *pstack;
-        struct perf_session_env *env;
+        struct perf_env *env;
         int                  print_seq;
         bool                 show_dso;
         bool                 show_headers;
@@ -1214,7 +1214,7 @@ static int hist_browser__dump(struct hist_browser *browser)
 
 static struct hist_browser *hist_browser__new(struct hists *hists,
                                               struct hist_browser_timer *hbt,
-                                              struct perf_session_env *env)
+                                              struct perf_env *env)
 {
         struct hist_browser *browser = zalloc(sizeof(*browser));
 
@@ -1695,7 +1695,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
                                     bool left_exits,
                                     struct hist_browser_timer *hbt,
                                     float min_pcnt,
-                                    struct perf_session_env *env)
+                                    struct perf_env *env)
 {
         struct hists *hists = evsel__hists(evsel);
         struct hist_browser *browser = hist_browser__new(hists, hbt, env);
@@ -2016,7 +2016,7 @@ struct perf_evsel_menu {
         struct perf_evsel *selection;
         bool lost_events, lost_events_warned;
         float min_pcnt;
-        struct perf_session_env *env;
+        struct perf_env *env;
 };
 
 static void perf_evsel_menu__write(struct ui_browser *browser,
@@ -2169,7 +2169,7 @@ static int __perf_evlist__tui_browse_hists(struct perf_evlist *evlist,
                                            int nr_entries, const char *help,
                                            struct hist_browser_timer *hbt,
                                            float min_pcnt,
-                                           struct perf_session_env *env)
+                                           struct perf_env *env)
 {
         struct perf_evsel *pos;
         struct perf_evsel_menu menu = {
@@ -2202,7 +2202,7 @@ static int __perf_evlist__tui_browse_hists(struct perf_evlist *evlist,
 int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
                                   struct hist_browser_timer *hbt,
                                   float min_pcnt,
-                                  struct perf_session_env *env)
+                                  struct perf_env *env)
 {
         int nr_entries = evlist->nr_entries;
 
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 4a2c2f0ead41..d909459fb54c 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -93,6 +93,38 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf)
         return raw - build_id;
 }
 
+int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
+{
+        char notes[PATH_MAX];
+        u8 build_id[BUILD_ID_SIZE];
+        int ret;
+
+        if (!root_dir)
+                root_dir = "";
+
+        scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
+
+        ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
+        if (ret < 0)
+                return ret;
+
+        return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+}
+
+int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
+{
+        u8 build_id[BUILD_ID_SIZE];
+        int ret;
+
+        ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
+        if (ret < 0)
+                return ret;
+        else if (ret != sizeof(build_id))
+                return -EINVAL;
+
+        return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+}
+
 /* asnprintf consolidates asprintf and snprintf */
 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 {
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index ce2f493f057a..27a14a8a945b 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -12,6 +12,9 @@ extern struct perf_tool build_id__mark_dso_hit_ops;
 struct dso;
 
 int build_id__sprintf(const u8 *build_id, int len, char *bf);
+int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
+int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
+
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size);
 
 int build_id__mark_dso_hit(struct perf_tool *tool, union perf_event *event,
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index e9a5d432902c..8d00039d6a20 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -98,6 +98,7 @@ static void perf_evlist__purge(struct perf_evlist *evlist)
 
         evlist__for_each_safe(evlist, n, pos) {
                 list_del_init(&pos->node);
+                pos->evlist = NULL;
                 perf_evsel__delete(pos);
         }
 
@@ -125,6 +126,7 @@ void perf_evlist__delete(struct perf_evlist *evlist)
 
 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
 {
+        entry->evlist = evlist;
         list_add_tail(&entry->node, &evlist->entries);
         entry->idx = evlist->nr_entries;
         entry->tracking = !entry->idx;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 436e358300b1..b39a6198f4ac 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -56,6 +56,7 @@ struct perf_evlist {
         struct cpu_map    *cpus;
         struct perf_evsel *selected;
         struct events_stats stats;
+        struct perf_env *env;
 };
 
 struct perf_evsel_str_handler {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index b096ef7a240c..bac25f41a751 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -206,6 +206,7 @@ void perf_evsel__init(struct perf_evsel *evsel,
         evsel->leader      = evsel;
         evsel->unit        = "";
         evsel->scale       = 1.0;
+        evsel->evlist      = NULL;
         INIT_LIST_HEAD(&evsel->node);
         INIT_LIST_HEAD(&evsel->config_terms);
         perf_evsel__object.init(evsel);
@@ -1026,6 +1027,7 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 void perf_evsel__exit(struct perf_evsel *evsel)
 {
         assert(list_empty(&evsel->node));
+        assert(evsel->evlist == NULL);
         perf_evsel__free_fd(evsel);
         perf_evsel__free_id(evsel);
         perf_evsel__free_config_terms(evsel);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 93ac6b128149..298e6bbca200 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -60,6 +60,9 @@ struct perf_evsel_config_term {
 
 /** struct perf_evsel - event selector
  *
+ * @evlist - evlist this evsel is in, if it is in one.
+ * @node - To insert it into evlist->entries or in other list_heads, say in
+ *         the event parsing routines.
  * @name - Can be set to retain the original event name passed by the user,
  *         so that when showing results in tools such as 'perf stat', we
  *         show the name used, not some alias.
@@ -73,6 +76,7 @@ struct perf_evsel_config_term {
  */
 struct perf_evsel {
         struct list_head        node;
+        struct perf_evlist      *evlist;
         struct perf_event_attr  attr;
         char                    *filter;
         struct xyarray          *fd;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 179b2bdd157d..41814547da15 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2514,6 +2514,7 @@ int perf_session__read_header(struct perf_session *session)
         if (session->evlist == NULL)
                 return -ENOMEM;
 
+        session->evlist->env = &header->env;
         if (perf_data_file__is_pipe(file))
                 return perf_header__read_pipe(session);
 
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 9b53b6525ce8..396e4965f0c9 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -66,7 +66,7 @@ struct perf_header;
 int perf_file_header__read(struct perf_file_header *header,
                            struct perf_header *ph, int fd);
 
-struct perf_session_env {
+struct perf_env {
         char                    *hostname;
         char                    *os_release;
         char                    *version;
@@ -98,7 +98,7 @@ struct perf_header {
         u64                             data_size;
         u64                             feat_offset;
         DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS);
-        struct perf_session_env         env;
+        struct perf_env         env;
 };
 
 struct perf_evlist;
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index bc528d54e457..de6d58e7f0d5 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -313,7 +313,7 @@ int hist_entry__tui_annotate(struct hist_entry *he, struct perf_evsel *evsel,
 int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
                                   struct hist_browser_timer *hbt,
                                   float min_pcnt,
-                                  struct perf_session_env *env);
+                                  struct perf_env *env);
 int script_browse(const char *script_opt);
 #else
 static inline
@@ -321,7 +321,7 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist __maybe_unused,
                                   const char *help __maybe_unused,
                                   struct hist_browser_timer *hbt __maybe_unused,
                                   float min_pcnt __maybe_unused,
-                                  struct perf_session_env *env __maybe_unused)
+                                  struct perf_env *env __maybe_unused)
 {
         return 0;
 }
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 18722e774a69..8a4537ee9bc3 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -170,7 +170,7 @@ static void perf_session__delete_threads(struct perf_session *session)
         machine__delete_threads(&session->machines.host);
 }
 
-static void perf_session_env__exit(struct perf_session_env *env)
+static void perf_session_env__exit(struct perf_env *env)
 {
         zfree(&env->hostname);
         zfree(&env->os_release);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 46ae0532a8a6..1f97ffb158a6 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1853,7 +1853,7 @@ static void vmlinux_path__exit(void)
         zfree(&vmlinux_path);
 }
 
-static int vmlinux_path__init(struct perf_session_env *env)
+static int vmlinux_path__init(struct perf_env *env)
 {
         struct utsname uts;
         char bf[PATH_MAX];
@@ -1964,7 +1964,7 @@ static bool symbol__read_kptr_restrict(void)
         return value;
 }
 
-int symbol__init(struct perf_session_env *env)
+int symbol__init(struct perf_env *env)
 {
         const char *symfs;
 
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a4cde92afbad..440ba8ae888f 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -252,8 +252,8 @@ int modules__parse(const char *filename, void *arg,
 int filename__read_debuglink(const char *filename, char *debuglink,
                              size_t size);
 
-struct perf_session_env;
-int symbol__init(struct perf_session_env *env);
+struct perf_env;
+int symbol__init(struct perf_env *env);
 void symbol__exit(void);
 void symbol__elf_init(void);
 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index f7adf1203df1..7acafb3c5592 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -34,6 +34,7 @@ bool test_attr__enabled;
 bool perf_host  = true;
 bool perf_guest = false;
 
+char tracing_path[PATH_MAX + 1]        = "/sys/kernel/debug/tracing";
 char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
 
 void event_attr_init(struct perf_event_attr *attr)
@@ -391,6 +392,8 @@ void set_term_quiet_input(struct termios *old)
 
 static void set_tracing_events_path(const char *tracing, const char *mountpoint)
 {
+        snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
+                 mountpoint, tracing);
         snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
                  mountpoint, tracing, "events");
 }
@@ -436,66 +439,14 @@ const char *perf_debugfs_mount(const char *mountpoint)
 
 void perf_debugfs_set_path(const char *mntpt)
 {
-        snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
         set_tracing_events_path("tracing/", mntpt);
 }
 
-static const char *find_tracefs(void)
-{
-        const char *path = __perf_tracefs_mount(NULL);
-
-        return path;
-}
-
-static const char *find_debugfs(void)
-{
-        const char *path = __perf_debugfs_mount(NULL);
-
-        if (!path)
-                fprintf(stderr, "Your kernel does not support the debugfs filesystem");
-
-        return path;
-}
-
-/*
- * Finds the path to the debugfs/tracing
- * Allocates the string and stores it.
- */
-const char *find_tracing_dir(void)
-{
-        const char *tracing_dir = "";
-        static char *tracing;
-        static int tracing_found;
-        const char *debugfs;
-
-        if (tracing_found)
-                return tracing;
-
-        debugfs = find_tracefs();
-        if (!debugfs) {
-                tracing_dir = "/tracing";
-                debugfs = find_debugfs();
-                if (!debugfs)
-                        return NULL;
-        }
-
-        if (asprintf(&tracing, "%s%s", debugfs, tracing_dir) < 0)
-                return NULL;
-
-        tracing_found = 1;
-        return tracing;
-}
-
 char *get_tracing_file(const char *name)
 {
-        const char *tracing;
         char *file;
 
-        tracing = find_tracing_dir();
-        if (!tracing)
-                return NULL;
-
-        if (asprintf(&file, "%s/%s", tracing, name) < 0)
+        if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
                 return NULL;
 
         return file;
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 88a891562a47..291be1d84bc3 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -83,10 +83,10 @@
 extern const char *graph_line;
 extern const char *graph_dotted_line;
 extern char buildid_dir[];
+extern char tracing_path[];
 extern char tracing_events_path[];
 extern void perf_debugfs_set_path(const char *mountpoint);
 const char *perf_debugfs_mount(const char *mountpoint);
-const char *find_tracing_dir(void);
 char *get_tracing_file(const char *name);
 void put_tracing_file(char *file);