Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Improve accuracy of perf/sched clock on x86.  (Adrian Hunter)

   - Intel DS and BTS updates.  (Alexander Shishkin)

   - Intel cstate PMU support.  (Kan Liang)

   - Add group read support to perf_event_read().  (Peter Zijlstra)

   - Branch call hardware sampling support, implemented on x86 and
     PowerPC.  (Stephane Eranian)

   - Event groups transactional interface enhancements.  (Sukadev
     Bhattiprolu)

   - Enable proper x86/intel/uncore PMU support on multi-segment PCI
     systems.  (Taku Izumi)

   - ... misc fixes and cleanups.

  The perf tooling team was very busy again with 200+ commits, the full
  diff doesn't fit into lkml size limits.  Here's an (incomplete) list
  of the tooling highlights:

  New features:

   - Change the default event used in all tools (record/top): use the
     most precise "cycles" hw counter available, i.e. when the user
     doesn't specify any event, it will try using cycles:ppp, cycles:pp,
     etc and fall back transparently until it finds a working counter.
     (Arnaldo Carvalho de Melo)

   - Integration of perf with eBPF that, given an eBPF .c source file
     (or .o file built for the 'bpf' target with clang), will get it
     automatically built, validated and loaded into the kernel via the
     sys_bpf syscall, which can then be used and seen using 'perf trace'
     and other tools.

     (Wang Nan)

  Various user interface improvements:

   - Automatic pager invocation on long help output.  (Namhyung Kim)

   - Search for more options when passing args to -h, e.g.: (Arnaldo
     Carvalho de Melo)

        $ perf report -h interface

        Usage: perf report [<options>]

         --gtk    Use the GTK2 interface
         --stdio  Use the stdio interface
         --tui    Use the TUI interface

   - Show ordered command line options when -h is used or when an
     unknown option is specified.  (Arnaldo Carvalho de Melo)

   - If options are passed after -h, show just its descriptions, not all
     options.  (Arnaldo Carvalho de Melo)

   - Implement column based horizontal scrolling in the hists browser
     (top, report), making it possible to use the TUI for things like
     'perf mem report' where there are many more columns than can fit in
     a terminal.  (Arnaldo Carvalho de Melo)

   - Enhance the error reporting of tracepoint event parsing, e.g.:

       $ oldperf record -e sched:sched_switc usleep 1
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint
       Run 'perf list' for a list of valid events

     Now we get the much nicer:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ can't access trace events

       Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_switc
       Hint:  Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

     And after we have those mount point permissions fixed:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint

       Error: File /sys/kernel/debug/tracing/events/sched/sched_switc not found.
       Hint:  Perhaps this kernel misses some CONFIG_ setting to enable this feature?.

     I.e.  basically now the event parsing routing uses the strerror_open()
     routines introduced by and used in 'perf trace' work.  (Jiri Olsa)

   - Fail properly when pattern matching fails to find a tracepoint,
     i.e. '-e non:existent' was being correctly handled, with a proper
     error message about that not being a valid event, but '-e
     non:existent*' wasn't, fix it.  (Jiri Olsa)

   - Do event name substring search as last resort in 'perf list'.
     (Arnaldo Carvalho de Melo)

     E.g.:

       # perf list clock

       List of pre-defined events (to be used in -e):

        cpu-clock                                          [Software event]
        task-clock                                         [Software event]

        uncore_cbox_0/clockticks/                          [Kernel PMU event]
        uncore_cbox_1/clockticks/                          [Kernel PMU event]

        kvm:kvm_pvclock_update                             [Tracepoint event]
        kvm:kvm_update_master_clock                        [Tracepoint event]
        power:clock_disable                                [Tracepoint event]
        power:clock_enable                                 [Tracepoint event]
        power:clock_set_rate                               [Tracepoint event]
        syscalls:sys_enter_clock_adjtime                   [Tracepoint event]
        syscalls:sys_enter_clock_getres                    [Tracepoint event]
        syscalls:sys_enter_clock_gettime                   [Tracepoint event]
        syscalls:sys_enter_clock_nanosleep                 [Tracepoint event]
        syscalls:sys_enter_clock_settime                   [Tracepoint event]
        syscalls:sys_exit_clock_adjtime                    [Tracepoint event]
        syscalls:sys_exit_clock_getres                     [Tracepoint event]
        syscalls:sys_exit_clock_gettime                    [Tracepoint event]
        syscalls:sys_exit_clock_nanosleep                  [Tracepoint event]
        syscalls:sys_exit_clock_settime                    [Tracepoint event]

  Intel PT hardware tracing enhancements:

   - Accept a zero --itrace period, meaning "as often as possible".  In
     the case of Intel PT that is the same as a period of 1 and a unit
     of 'instructions' (i.e.  --itrace=i1i).  (Adrian Hunter)

   - Harmonize itrace's synthesized callchains with the existing
     --max-stack tool option.  (Adrian Hunter)

   - Allow time to be displayed in nanoseconds in 'perf script'.
     (Adrian Hunter)

   - Fix potential infinite loop when handling Intel PT timestamps.
     (Adrian Hunter)

   - Slighly improve Intel PT debug logging.  (Adrian Hunter)

   - Warn when AUX data has been lost, just like when processing
     PERF_RECORD_LOST.  (Adrian Hunter)

   - Further document export-to-postgresql.py script.  (Adrian Hunter)

   - Add option to synthesize branch stack from auxtrace data.  (Adrian
     Hunter)

  Misc notable changes:

   - Switch the default callchain output mode to 'graph,0.5,caller', to
     make it look like the default for other tools, reducing the
     learning curve for people used to 'caller' based viewing.  (Arnaldo
     Carvalho de Melo)

   - various call chain usability enhancements.  (Namhyung Kim)

   - Introduce the 'P' event modifier, meaning 'max precision level,
     please', i.e.:

        $ perf record -e cycles:P usleep 1

     Is now similar to:

        $ perf record usleep 1

     Useful, for instance, when specifying multiple events.  (Jiri Olsa)

   - Add 'socket' sort entry, to sort by the processor socket in 'perf
     top' and 'perf report'.  (Kan Liang)

   - Introduce --socket-filter to 'perf report', for filtering by
     processor socket.  (Kan Liang)

   - Add new "Zoom into Processor Socket" operation in the perf hists
     browser, used in 'perf top' and 'perf report'.  (Kan Liang)

   - Allow probing on kmodules without DWARF.  (Masami Hiramatsu)

   - Fix 'perf probe -l' for probes added to kernel module functions.
     (Masami Hiramatsu)

   - Preparatory work for the 'perf stat record' feature that will allow
     generating perf.data files with counting data in addition to the
     sampling mode we have now (Jiri Olsa)

   - Update libtraceevent KVM plugin.  (Paolo Bonzini)

   - ... plus lots of other enhancements that I failed to list properly,
     by: Adrian Hunter, Alexander Shishkin, Andi Kleen, Andrzej Hajda,
     Arnaldo Carvalho de Melo, Dima Kogan, Don Zickus, Geliang Tang, He
     Kuang, Huaitong Han, Ingo Molnar, Jan Stancek, Jiri Olsa, Kan
     Liang, Kirill Tkhai, Masami Hiramatsu, Matt Fleming, Namhyung Kim,
     Paolo Bonzini, Peter Zijlstra, Rabin Vincent, Scott Wood, Stephane
     Eranian, Sukadev Bhattiprolu, Taku Izumi, Vaishali Thakkar, Wang
     Nan, Yang Shi and Yunlong Song"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (260 commits)
  perf unwind: Pass symbol source to libunwind
  tools build: Fix libiberty feature detection
  perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
  perf record: Add clang options for compiling BPF scripts
  perf bpf: Attach eBPF filter to perf event
  perf tools: Make sure fixdep is built before libbpf
  perf script: Enable printing of branch stack
  perf trace: Add cmd string table to decode sys_bpf first arg
  perf bpf: Collect perf_evsel in BPF object files
  perf tools: Load eBPF object into kernel
  perf tools: Create probe points for BPF programs
  perf tools: Enable passing bpf object file to --event
  perf ebpf: Add the libbpf glue
  perf tools: Make perf depend on libbpf
  perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore
  perf tools: Enable pre-event inherit setting by config terms
  perf symbols: we can now read separate debug-info files based on a build ID
  perf symbols: Fix type error when reading a build-id
  perf tools: Search for more options when passing args to -h
  perf stat: Cache aggregated map entries in extra cpumap
  ...

1 files changed, 153 insertions, 12 deletions

diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 128ef6332a6b..459599d1b6c4 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -1,7 +1,6 @@
-/* TODO merge/factor in debugfs.c here */
-
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -11,10 +10,29 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/mount.h>
 
-#include "debugfs.h"
 #include "fs.h"
 
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+#ifndef SYSFS_MAGIC
+#define SYSFS_MAGIC            0x62656572
+#endif
+
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC       0x9fa0
+#endif
+
+#ifndef DEBUGFS_MAGIC
+#define DEBUGFS_MAGIC          0x64626720
+#endif
+
+#ifndef TRACEFS_MAGIC
+#define TRACEFS_MAGIC          0x74726163
+#endif
+
 static const char * const sysfs__fs_known_mountpoints[] = {
 	"/sys",
 	0,
@@ -25,19 +43,48 @@ static const char * const procfs__known_mountpoints[] = {
 	0,
 };
 
+#ifndef DEBUGFS_DEFAULT_PATH
+#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
+#endif
+
+static const char * const debugfs__known_mountpoints[] = {
+	DEBUGFS_DEFAULT_PATH,
+	"/debug",
+	0,
+};
+
+
+#ifndef TRACEFS_DEFAULT_PATH
+#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing"
+#endif
+
+static const char * const tracefs__known_mountpoints[] = {
+	TRACEFS_DEFAULT_PATH,
+	"/sys/kernel/debug/tracing",
+	"/tracing",
+	"/trace",
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
-	char			 path[PATH_MAX + 1];
+	char			 path[PATH_MAX];
 	bool			 found;
 	long			 magic;
 };
 
 enum {
-	FS__SYSFS  = 0,
-	FS__PROCFS = 1,
+	FS__SYSFS   = 0,
+	FS__PROCFS  = 1,
+	FS__DEBUGFS = 2,
+	FS__TRACEFS = 3,
 };
 
+#ifndef TRACEFS_MAGIC
+#define TRACEFS_MAGIC 0x74726163
+#endif
+
 static struct fs fs__entries[] = {
 	[FS__SYSFS] = {
 		.name	= "sysfs",
@@ -49,6 +96,16 @@ static struct fs fs__entries[] = {
 		.mounts	= procfs__known_mountpoints,
 		.magic	= PROC_SUPER_MAGIC,
 	},
+	[FS__DEBUGFS] = {
+		.name	= "debugfs",
+		.mounts	= debugfs__known_mountpoints,
+		.magic	= DEBUGFS_MAGIC,
+	},
+	[FS__TRACEFS] = {
+		.name	= "tracefs",
+		.mounts	= tracefs__known_mountpoints,
+		.magic	= TRACEFS_MAGIC,
+	},
 };
 
 static bool fs__read_mounts(struct fs *fs)
@@ -159,14 +216,54 @@ static const char *fs__mountpoint(int idx)
 	return fs__get_mountpoint(fs);
 }
 
-#define FS__MOUNTPOINT(name, idx)	\
-const char *name##__mountpoint(void)	\
-{					\
-	return fs__mountpoint(idx);	\
+static const char *mount_overload(struct fs *fs)
+{
+	size_t name_len = strlen(fs->name);
+	/* "PERF_" + name + "_ENVIRONMENT" + '\0' */
+	char upper_name[5 + name_len + 12 + 1];
+
+	snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name);
+	mem_toupper(upper_name, name_len);
+
+	return getenv(upper_name) ?: *fs->mounts;
+}
+
+static const char *fs__mount(int idx)
+{
+	struct fs *fs = &fs__entries[idx];
+	const char *mountpoint;
+
+	if (fs__mountpoint(idx))
+		return (const char *)fs->path;
+
+	mountpoint = mount_overload(fs);
+
+	if (mount(NULL, mountpoint, fs->name, 0, NULL) < 0)
+		return NULL;
+
+	return fs__check_mounts(fs) ? fs->path : NULL;
+}
+
+#define FS(name, idx)				\
+const char *name##__mountpoint(void)		\
+{						\
+	return fs__mountpoint(idx);		\
+}						\
+						\
+const char *name##__mount(void)			\
+{						\
+	return fs__mount(idx);			\
+}						\
+						\
+bool name##__configured(void)			\
+{						\
+	return name##__mountpoint() != NULL;	\
 }
 
-FS__MOUNTPOINT(sysfs,  FS__SYSFS);
-FS__MOUNTPOINT(procfs, FS__PROCFS);
+FS(sysfs,   FS__SYSFS);
+FS(procfs,  FS__PROCFS);
+FS(debugfs, FS__DEBUGFS);
+FS(tracefs, FS__TRACEFS);
 
 int filename__read_int(const char *filename, int *value)
 {
@@ -185,6 +282,50 @@ int filename__read_int(const char *filename, int *value)
 	return err;
 }
 
+int filename__read_ull(const char *filename, unsigned long long *value)
+{
+	char line[64];
+	int fd = open(filename, O_RDONLY), err = -1;
+
+	if (fd < 0)
+		return -1;
+
+	if (read(fd, line, sizeof(line)) > 0) {
+		*value = strtoull(line, NULL, 10);
+		if (*value != ULLONG_MAX)
+			err = 0;
+	}
+
+	close(fd);
+	return err;
+}
+
+int sysfs__read_ull(const char *entry, unsigned long long *value)
+{
+	char path[PATH_MAX];
+	const char *sysfs = sysfs__mountpoint();
+
+	if (!sysfs)
+		return -1;
+
+	snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+	return filename__read_ull(path, value);
+}
+
+int sysfs__read_int(const char *entry, int *value)
+{
+	char path[PATH_MAX];
+	const char *sysfs = sysfs__mountpoint();
+
+	if (!sysfs)
+		return -1;
+
+	snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
+
+	return filename__read_int(path, value);
+}
+
 int sysctl__read_int(const char *sysctl, int *value)
 {
 	char path[PATH_MAX];