36 files changed, 521 insertions, 347 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 3b8f7b80376b..e9d5c271db69 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -30,6 +30,8 @@ endif
 # Define EXTRA_CFLAGS=-m64 or EXTRA_CFLAGS=-m32 as appropriate for cross-builds.
 #
 # Define NO_DWARF if you do not want debug-info analysis feature at all.
+#
+# Define WERROR=0 to disable treating any warnings as errors.
 
 $(OUTPUT)PERF-VERSION-FILE: .FORCE-PERF-VERSION-FILE
         @$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT)
@@ -63,6 +65,11 @@ ifeq ($(ARCH),x86_64)
         endif
 endif
 
+# Treat warnings as errors unless directed not to
+ifneq ($(WERROR),0)
+        CFLAGS_WERROR := -Werror
+endif
+
 #
 # Include saner warnings here, which can catch bugs:
 #
@@ -95,7 +102,7 @@ ifndef PERF_DEBUG
   CFLAGS_OPTIMIZE = -O6
 endif
 
-CFLAGS = -fno-omit-frame-pointer -ggdb3 -Wall -Wextra -std=gnu99 -Werror $(CFLAGS_OPTIMIZE) -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
+CFLAGS = -fno-omit-frame-pointer -ggdb3 -Wall -Wextra -std=gnu99 $(CFLAGS_WERROR) $(CFLAGS_OPTIMIZE) -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
 EXTLIBS = -lpthread -lrt -lelf -lm
 ALL_CFLAGS = $(CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
 ALL_LDFLAGS = $(LDFLAGS)
diff --git a/tools/perf/arch/arm/util/dwarf-regs.c b/tools/perf/arch/arm/util/dwarf-regs.c
index fff6450c8c99..e8d5c551c69c 100644
--- a/tools/perf/arch/arm/util/dwarf-regs.c
+++ b/tools/perf/arch/arm/util/dwarf-regs.c
@@ -8,7 +8,10 @@
  * published by the Free Software Foundation.
  */
 
+#include <stdlib.h>
+#ifndef __UCLIBC__
 #include <libio.h>
+#endif
 #include <dwarf-regs.h>
 
 struct pt_regs_dwarfnum {
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6b0519f885e4..f4c3fbee4bad 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -161,6 +161,7 @@ static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist)
         struct perf_event_attr *attr = &evsel->attr;
         int track = !evsel->idx; /* only the first counter needs these */
 
+        attr->disabled          = 1;
         attr->inherit           = !no_inherit;
         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
@@ -671,6 +672,8 @@ static int __cmd_record(int argc, const char **argv)
                 }
         }
 
+        perf_evlist__enable(evsel_list);
+
         /*
          * Let the child rip
          */
diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 55f4c76f2821..efe696f936e2 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -561,7 +561,7 @@ static int test__basic_mmap(void)
                 }
 
                 err = perf_event__parse_sample(event, attr.sample_type, sample_size,
-                                               false, &sample);
+                                               false, &sample, false);
                 if (err) {
                         pr_err("Can't parse sample, err = %d\n", err);
                         goto out_munmap;
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index a43433f08300..d28013b7d61c 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -191,7 +191,8 @@ static void __zero_source_counters(struct sym_entry *syme)
         symbol__annotate_zero_histograms(sym);
 }
 
-static void record_precise_ip(struct sym_entry *syme, int counter, u64 ip)
+static void record_precise_ip(struct sym_entry *syme, struct map *map,
+                              int counter, u64 ip)
 {
         struct annotation *notes;
         struct symbol *sym;
@@ -205,8 +206,8 @@ static void record_precise_ip(struct sym_entry *syme, int counter, u64 ip)
         if (pthread_mutex_trylock(&notes->lock))
                 return;
 
-        ip = syme->map->map_ip(syme->map, ip);
-        symbol__inc_addr_samples(sym, syme->map, counter, ip);
+        ip = map->map_ip(map, ip);
+        symbol__inc_addr_samples(sym, map, counter, ip);
 
         pthread_mutex_unlock(&notes->lock);
 }
@@ -810,7 +811,7 @@ static void perf_event__process_sample(const union perf_event *event,
                 evsel = perf_evlist__id2evsel(top.evlist, sample->id);
                 assert(evsel != NULL);
                 syme->count[evsel->idx]++;
-                record_precise_ip(syme, evsel->idx, ip);
+                record_precise_ip(syme, al.map, evsel->idx, ip);
                 pthread_mutex_lock(&top.active_symbols_lock);
                 if (list_empty(&syme->node) || !syme->node.next) {
                         static bool first = true;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 3c1b8a632101..437f8ca679a0 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -169,12 +169,17 @@ static int perf_event__synthesize_mmap_events(union perf_event *event,
                         continue;
                 pbf += n + 3;
                 if (*pbf == 'x') { /* vm_exec */
+                        char anonstr[] = "//anon\n";
                         char *execname = strchr(bf, '/');
 
                         /* Catch VDSO */
                         if (execname == NULL)
                                 execname = strstr(bf, "[vdso]");
 
+                        /* Catch anonymous mmaps */
+                        if ((execname == NULL) && !strstr(bf, "["))
+                                execname = anonstr;
+
                         if (execname == NULL)
                                 continue;
 
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 1d7f66488a88..357a85b85248 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -186,6 +186,6 @@ const char *perf_event__name(unsigned int id);
 
 int perf_event__parse_sample(const union perf_event *event, u64 type,
                              int sample_size, bool sample_id_all,
-                             struct perf_sample *sample);
+                             struct perf_sample *sample, bool swapped);
 
 #endif /* __PERF_RECORD_H */
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index c12bd476c6f7..72e9f4886b6d 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -113,6 +113,19 @@ void perf_evlist__disable(struct perf_evlist *evlist)
         }
 }
 
+void perf_evlist__enable(struct perf_evlist *evlist)
+{
+        int cpu, thread;
+        struct perf_evsel *pos;
+
+        for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
+                list_for_each_entry(pos, &evlist->entries, node) {
+                        for (thread = 0; thread < evlist->threads->nr; thread++)
+                                ioctl(FD(pos, cpu, thread), PERF_EVENT_IOC_ENABLE);
+                }
+        }
+}
+
 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
         int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index ce85ae9ae57a..f34915002745 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -54,6 +54,7 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite);
 void perf_evlist__munmap(struct perf_evlist *evlist);
 
 void perf_evlist__disable(struct perf_evlist *evlist);
+void perf_evlist__enable(struct perf_evlist *evlist);
 
 static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
                                          struct cpu_map *cpus,
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a03a36b7908a..c5748c52318f 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -7,6 +7,8 @@
  * Released under the GPL v2. (and only v2, not any later version)
  */
 
+#include <byteswap.h>
+#include "asm/bug.h"
 #include "evsel.h"
 #include "evlist.h"
 #include "util.h"
@@ -342,10 +344,20 @@ static bool sample_overlap(const union perf_event *event,
 
 int perf_event__parse_sample(const union perf_event *event, u64 type,
                              int sample_size, bool sample_id_all,
-                             struct perf_sample *data)
+                             struct perf_sample *data, bool swapped)
 {
         const u64 *array;
 
+        /*
+         * used for cross-endian analysis. See git commit 65014ab3
+         * for why this goofiness is needed.
+         */
+        union {
+                u64 val64;
+                u32 val32[2];
+        } u;
+
+
         data->cpu = data->pid = data->tid = -1;
         data->stream_id = data->id = data->time = -1ULL;
 
@@ -366,9 +378,16 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
         }
 
         if (type & PERF_SAMPLE_TID) {
-                u32 *p = (u32 *)array;
-                data->pid = p[0];
-                data->tid = p[1];
+                u.val64 = *array;
+                if (swapped) {
+                        /* undo swap of u64, then swap on individual u32s */
+                        u.val64 = bswap_64(u.val64);
+                        u.val32[0] = bswap_32(u.val32[0]);
+                        u.val32[1] = bswap_32(u.val32[1]);
+                }
+
+                data->pid = u.val32[0];
+                data->tid = u.val32[1];
                 array++;
         }
 
@@ -395,8 +414,15 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
         }
 
         if (type & PERF_SAMPLE_CPU) {
-                u32 *p = (u32 *)array;
-                data->cpu = *p;
+
+                u.val64 = *array;
+                if (swapped) {
+                        /* undo swap of u64, then swap on individual u32s */
+                        u.val64 = bswap_64(u.val64);
+                        u.val32[0] = bswap_32(u.val32[0]);
+                }
+
+                data->cpu = u.val32[0];
                 array++;
         }
 
@@ -423,18 +449,24 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
         }
 
         if (type & PERF_SAMPLE_RAW) {
-                u32 *p = (u32 *)array;
+                u.val64 = *array;
+                if (WARN_ONCE(swapped,
+                              "Endianness of raw data not corrected!\n")) {
+                        /* undo swap of u64, then swap on individual u32s */
+                        u.val64 = bswap_64(u.val64);
+                        u.val32[0] = bswap_32(u.val32[0]);
+                        u.val32[1] = bswap_32(u.val32[1]);
+                }
 
                 if (sample_overlap(event, array, sizeof(u32)))
                         return -EFAULT;
 
-                data->raw_size = *p;
-                p++;
+                data->raw_size = u.val32[0];
 
-                if (sample_overlap(event, p, data->raw_size))
+                if (sample_overlap(event, &u.val32[1], data->raw_size))
                         return -EFAULT;
 
-                data->raw_data = p;
+                data->raw_data = &u.val32[1];
         }
 
         return 0;
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 555fc3864b90..5d732621a462 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -659,7 +659,7 @@ static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
                         ret = -ENOENT;
         }
-        if (ret == 0)
+        if (ret >= 0)
                 ret = convert_variable(&vr_die, pf);
 
         if (ret < 0)
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index cbc8f215d4b7..7624324efad4 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -803,7 +803,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
                 first = list_entry(evlist->entries.next, struct perf_evsel, node);
                 err = perf_event__parse_sample(event, first->attr.sample_type,
                                                perf_evsel__sample_size(first),
-                                               sample_id_all, &pevent->sample);
+                                               sample_id_all, &pevent->sample, false);
                 if (err)
                         return PyErr_Format(PyExc_OSError,
                                             "perf: can't parse sample, err=%d", err);
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 170601e67d6b..974d0cbee5e9 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -162,7 +162,8 @@ static inline int perf_session__parse_sample(struct perf_session *session,
 {
         return perf_event__parse_sample(event, session->sample_type,
                                         session->sample_size,
-                                        session->sample_id_all, sample);
+                                        session->sample_id_all, sample,
+                                        session->header.needs_swap);
 }
 
 struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 401e220566fd..1ee8f1e40f18 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -151,11 +151,17 @@ sort__sym_cmp(struct hist_entry *left, struct hist_entry *right)
 {
         u64 ip_l, ip_r;
 
+        if (!left->ms.sym && !right->ms.sym)
+                return right->level - left->level;
+
+        if (!left->ms.sym || !right->ms.sym)
+                return cmp_null(left->ms.sym, right->ms.sym);
+
         if (left->ms.sym == right->ms.sym)
                 return 0;
 
-        ip_l = left->ms.sym ? left->ms.sym->start : left->ip;
-        ip_r = right->ms.sym ? right->ms.sym->start : right->ip;
+        ip_l = left->ms.sym->start;
+        ip_r = right->ms.sym->start;
 
         return (int64_t)(ip_r - ip_l);
 }
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 469c0264ed29..40eeaf07725b 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -74,16 +74,104 @@ static void dso__set_sorted_by_name(struct dso *dso, enum map_type type)
 
 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
 {
+        symbol_type = toupper(symbol_type);
+
         switch (map_type) {
         case MAP__FUNCTION:
                 return symbol_type == 'T' || symbol_type == 'W';
         case MAP__VARIABLE:
-                return symbol_type == 'D' || symbol_type == 'd';
+                return symbol_type == 'D';
         default:
                 return false;
         }
 }
 
+static int prefix_underscores_count(const char *str)
+{
+        const char *tail = str;
+
+        while (*tail == '_')
+                tail++;
+
+        return tail - str;
+}
+
+#define SYMBOL_A 0
+#define SYMBOL_B 1
+
+static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
+{
+        s64 a;
+        s64 b;
+
+        /* Prefer a symbol with non zero length */
+        a = syma->end - syma->start;
+        b = symb->end - symb->start;
+        if ((b == 0) && (a > 0))
+                return SYMBOL_A;
+        else if ((a == 0) && (b > 0))
+                return SYMBOL_B;
+
+        /* Prefer a non weak symbol over a weak one */
+        a = syma->binding == STB_WEAK;
+        b = symb->binding == STB_WEAK;
+        if (b && !a)
+                return SYMBOL_A;
+        if (a && !b)
+                return SYMBOL_B;
+
+        /* Prefer a global symbol over a non global one */
+        a = syma->binding == STB_GLOBAL;
+        b = symb->binding == STB_GLOBAL;
+        if (a && !b)
+                return SYMBOL_A;
+        if (b && !a)
+                return SYMBOL_B;
+
+        /* Prefer a symbol with less underscores */
+        a = prefix_underscores_count(syma->name);
+        b = prefix_underscores_count(symb->name);
+        if (b > a)
+                return SYMBOL_A;
+        else if (a > b)
+                return SYMBOL_B;
+
+        /* If all else fails, choose the symbol with the longest name */
+        if (strlen(syma->name) >= strlen(symb->name))
+                return SYMBOL_A;
+        else
+                return SYMBOL_B;
+}
+
+static void symbols__fixup_duplicate(struct rb_root *symbols)
+{
+        struct rb_node *nd;
+        struct symbol *curr, *next;
+
+        nd = rb_first(symbols);
+
+        while (nd) {
+                curr = rb_entry(nd, struct symbol, rb_node);
+again:
+                nd = rb_next(&curr->rb_node);
+                next = rb_entry(nd, struct symbol, rb_node);
+
+                if (!nd)
+                        break;
+
+                if (curr->start != next->start)
+                        continue;
+
+                if (choose_best_symbol(curr, next) == SYMBOL_A) {
+                        rb_erase(&next->rb_node, symbols);
+                        goto again;
+                } else {
+                        nd = rb_next(&curr->rb_node);
+                        rb_erase(&curr->rb_node, symbols);
+                }
+        }
+}
+
 static void symbols__fixup_end(struct rb_root *symbols)
 {
         struct rb_node *nd, *prevnd = rb_first(symbols);
@@ -438,18 +526,11 @@ int kallsyms__parse(const char *filename, void *arg,
         char *line = NULL;
         size_t n;
         int err = -1;
-        u64 prev_start = 0;
-        char prev_symbol_type = 0;
-        char *prev_symbol_name;
         FILE *file = fopen(filename, "r");
 
         if (file == NULL)
                 goto out_failure;
 
-        prev_symbol_name = malloc(KSYM_NAME_LEN);
-        if (prev_symbol_name == NULL)
-                goto out_close;
-
         err = 0;
 
         while (!feof(file)) {
@@ -470,7 +551,7 @@ int kallsyms__parse(const char *filename, void *arg,
                 if (len + 2 >= line_len)
                         continue;
 
-                symbol_type = toupper(line[len]);
+                symbol_type = line[len];
                 len += 2;
                 symbol_name = line + len;
                 len = line_len - len;
@@ -480,24 +561,18 @@ int kallsyms__parse(const char *filename, void *arg,
                         break;
                 }
 
-                if (prev_symbol_type) {
-                        u64 end = start;
-                        if (end != prev_start)
-                                --end;
-                        err = process_symbol(arg, prev_symbol_name,
-                                             prev_symbol_type, prev_start, end);
-                        if (err)
-                                break;
-                }
-
-                memcpy(prev_symbol_name, symbol_name, len + 1);
-                prev_symbol_type = symbol_type;
-                prev_start = start;
+                /*
+                 * module symbols are not sorted so we add all
+                 * symbols with zero length and rely on
+                 * symbols__fixup_end() to fix it up.
+                 */
+                err = process_symbol(arg, symbol_name,
+                                     symbol_type, start, start);
+                if (err)
+                        break;
         }
 
-        free(prev_symbol_name);
         free(line);
-out_close:
         fclose(file);
         return err;
 
@@ -703,6 +778,9 @@ int dso__load_kallsyms(struct dso *dso, const char *filename,
         if (dso__load_all_kallsyms(dso, filename, map) < 0)
                 return -1;
 
+        symbols__fixup_duplicate(&dso->symbols[map->type]);
+        symbols__fixup_end(&dso->symbols[map->type]);
+
         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
                 dso->symtab_type = SYMTAB__GUEST_KALLSYMS;
         else
@@ -1092,8 +1170,7 @@ static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
         if (dso->has_build_id) {
                 u8 build_id[BUILD_ID_SIZE];
 
-                if (elf_read_build_id(elf, build_id,
-                                      BUILD_ID_SIZE) != BUILD_ID_SIZE)
+                if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
                         goto out_elf_end;
 
                 if (!dso__build_id_equal(dso, build_id))
@@ -1111,6 +1188,8 @@ static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
         }
 
         opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
+        if (opdshdr.sh_type != SHT_PROGBITS)
+                opdsec = NULL;
         if (opdsec)
                 opddata = elf_rawdata(opdsec, NULL);
 
@@ -1276,6 +1355,7 @@ new_symbol:
          * For misannotated, zeroed, ASM function sizes.
          */
         if (nr > 0) {
+                symbols__fixup_duplicate(&dso->symbols[map->type]);
                 symbols__fixup_end(&dso->symbols[map->type]);
                 if (kmap) {
                         /*
@@ -1362,8 +1442,8 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
         ptr = data->d_buf;
         while (ptr < (data->d_buf + data->d_size)) {
                 GElf_Nhdr *nhdr = ptr;
-                int namesz = NOTE_ALIGN(nhdr->n_namesz),
-                    descsz = NOTE_ALIGN(nhdr->n_descsz);
+                size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
+                       descsz = NOTE_ALIGN(nhdr->n_descsz);
                 const char *name;
 
                 ptr += sizeof(*nhdr);
@@ -1372,8 +1452,10 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
                     nhdr->n_namesz == sizeof("GNU")) {
                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
-                                memcpy(bf, ptr, BUILD_ID_SIZE);
-                                err = BUILD_ID_SIZE;
+                                size_t sz = min(size, descsz);
+                                memcpy(bf, ptr, sz);
+                                memset(bf + sz, 0, size - sz);
+                                err = descsz;
                                 break;
                         }
                 }
@@ -1425,7 +1507,7 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
         while (1) {
                 char bf[BUFSIZ];
                 GElf_Nhdr nhdr;
-                int namesz, descsz;
+                size_t namesz, descsz;
 
                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
                         break;
@@ -1434,15 +1516,16 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
                 descsz = NOTE_ALIGN(nhdr.n_descsz);
                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
                     nhdr.n_namesz == sizeof("GNU")) {
-                        if (read(fd, bf, namesz) != namesz)
+                        if (read(fd, bf, namesz) != (ssize_t)namesz)
                                 break;
                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
-                                if (read(fd, build_id,
-                                    BUILD_ID_SIZE) == BUILD_ID_SIZE) {
+                                size_t sz = min(descsz, size);
+                                if (read(fd, build_id, sz) == (ssize_t)sz) {
+                                        memset(build_id + sz, 0, size - sz);
                                         err = 0;
                                         break;
                                 }
-                        } else if (read(fd, bf, descsz) != descsz)
+                        } else if (read(fd, bf, descsz) != (ssize_t)descsz)
                                 break;
                 } else {
                         int n = namesz + descsz;
diff --git a/tools/power/cpupower/Makefile b/tools/power/cpupower/Makefile
index 94c2cf0a98b8..e8a03aceceb1 100644
--- a/tools/power/cpupower/Makefile
+++ b/tools/power/cpupower/Makefile
@@ -24,7 +24,7 @@
 
 # Set the following to `true' to make a unstripped, unoptimized
 # binary. Leave this set to `false' for production use.
-DEBUG ?=        false
+DEBUG ?=        true
 
 # make the build silent. Set this to something else to make it noisy again.
 V ?=            false
@@ -35,7 +35,7 @@ NLS ?=		true
 
 # Set the following to 'true' to build/install the
 # cpufreq-bench benchmarking tool
-CPUFRQ_BENCH ?= true
+CPUFREQ_BENCH ?= true
 
 # Prefix to the directories we're installing to
 DESTDIR ?=
@@ -137,9 +137,10 @@ CFLAGS +=	-pipe
 ifeq ($(strip $(NLS)),true)
         INSTALL_NLS += install-gmo
         COMPILE_NLS += create-gmo
+        CFLAGS += -DNLS
 endif
 
-ifeq ($(strip $(CPUFRQ_BENCH)),true)
+ifeq ($(strip $(CPUFREQ_BENCH)),true)
         INSTALL_BENCH += install-bench
         COMPILE_BENCH += compile-bench
 endif
diff --git a/tools/power/cpupower/debug/x86_64/Makefile b/tools/power/cpupower/debug/x86_64/Makefile
index dbf13998462a..3326217dd311 100644
--- a/tools/power/cpupower/debug/x86_64/Makefile
+++ b/tools/power/cpupower/debug/x86_64/Makefile
@@ -1,10 +1,10 @@
 default: all
 
-centrino-decode: centrino-decode.c
-        $(CC) $(CFLAGS) -o centrino-decode centrino-decode.c
+centrino-decode: ../i386/centrino-decode.c
+        $(CC) $(CFLAGS) -o $@ $<
 
-powernow-k8-decode: powernow-k8-decode.c
-        $(CC) $(CFLAGS) -o powernow-k8-decode powernow-k8-decode.c
+powernow-k8-decode: ../i386/powernow-k8-decode.c
+        $(CC) $(CFLAGS) -o $@ $<
 
 all: centrino-decode powernow-k8-decode
 
diff --git a/tools/power/cpupower/debug/x86_64/centrino-decode.c b/tools/power/cpupower/debug/x86_64/centrino-decode.c
deleted file mode 120000
index 26fb3f1d8fc7..000000000000
--- a/tools/power/cpupower/debug/x86_64/centrino-decode.c
+++ /dev/null
@@ -1 +0,0 @@
-../i386/centrino-decode.c
\ No newline at end of file
diff --git a/tools/power/cpupower/debug/x86_64/powernow-k8-decode.c b/tools/power/cpupower/debug/x86_64/powernow-k8-decode.c
deleted file mode 120000
index eb30c79cf9df..000000000000
--- a/tools/power/cpupower/debug/x86_64/powernow-k8-decode.c
+++ /dev/null
@@ -1 +0,0 @@
-../i386/powernow-k8-decode.c
\ No newline at end of file
diff --git a/tools/power/cpupower/man/cpupower-frequency-info.1 b/tools/power/cpupower/man/cpupower-frequency-info.1
index 3194811d58f5..bb60a8d1e45a 100644
--- a/tools/power/cpupower/man/cpupower-frequency-info.1
+++ b/tools/power/cpupower/man/cpupower-frequency-info.1
@@ -1,10 +1,10 @@
-.TH "cpufreq-info" "1" "0.1" "Mattia Dongili" ""
+.TH "cpupower-frequency-info" "1" "0.1" "Mattia Dongili" ""
 .SH "NAME"
 .LP 
-cpufreq\-info \- Utility to retrieve cpufreq kernel information
+cpupower frequency\-info \- Utility to retrieve cpufreq kernel information
 .SH "SYNTAX"
 .LP 
-cpufreq\-info [\fIoptions\fP]
+cpupower [ \-c cpulist ] frequency\-info [\fIoptions\fP]
 .SH "DESCRIPTION"
 .LP 
 A small tool which prints out cpufreq information helpful to developers and interested users.
diff --git a/tools/power/cpupower/man/cpupower-frequency-set.1 b/tools/power/cpupower/man/cpupower-frequency-set.1
index 26e3e13eee3b..685f469093ad 100644
--- a/tools/power/cpupower/man/cpupower-frequency-set.1
+++ b/tools/power/cpupower/man/cpupower-frequency-set.1
@@ -1,13 +1,13 @@
-.TH "cpufreq-set" "1" "0.1" "Mattia Dongili" ""
+.TH "cpupower-freqency-set" "1" "0.1" "Mattia Dongili" ""
 .SH "NAME"
 .LP 
-cpufreq\-set \- A small tool which allows to modify cpufreq settings.
+cpupower frequency\-set \- A small tool which allows to modify cpufreq settings.
 .SH "SYNTAX"
 .LP 
-cpufreq\-set [\fIoptions\fP]
+cpupower [ \-c cpu ] frequency\-set [\fIoptions\fP]
 .SH "DESCRIPTION"
 .LP 
-cpufreq\-set allows you to modify cpufreq settings without having to type e.g. "/sys/devices/system/cpu/cpu0/cpufreq/scaling_set_speed" all the time.
+cpupower frequency\-set allows you to modify cpufreq settings without having to type e.g. "/sys/devices/system/cpu/cpu0/cpufreq/scaling_set_speed" all the time.
 .SH "OPTIONS"
 .LP 
 .TP 
diff --git a/tools/power/cpupower/man/cpupower.1 b/tools/power/cpupower/man/cpupower.1
index 78c20feab85c..baf741d06e82 100644
--- a/tools/power/cpupower/man/cpupower.1
+++ b/tools/power/cpupower/man/cpupower.1
@@ -3,7 +3,7 @@
 cpupower \- Shows and sets processor power related values
 .SH SYNOPSIS
 .ft B
-.B cpupower [ \-c cpulist ] subcommand [ARGS]
+.B cpupower [ \-c cpulist ] <command> [ARGS]
 
 .B cpupower \-v|\-\-version
 
@@ -13,24 +13,24 @@ cpupower \- Shows and sets processor power related values
 \fBcpupower \fP is a collection of tools to examine and tune power saving
 related features of your processor.
 
-The manpages of the subcommands (cpupower\-<subcommand>(1)) provide detailed
+The manpages of the commands (cpupower\-<command>(1)) provide detailed
 descriptions of supported features. Run \fBcpupower help\fP to get an overview
-of supported subcommands.
+of supported commands.
 
 .SH Options
 .PP
 \-\-help, \-h
 .RS 4
-Shows supported subcommands and general usage.
+Shows supported commands and general usage.
 .RE
 .PP
 \-\-cpu cpulist,  \-c cpulist
 .RS 4
 Only show or set values for specific cores.
-This option is not supported by all subcommands, details can be found in the
-manpages of the subcommands.
+This option is not supported by all commands, details can be found in the
+manpages of the commands.
 
-Some subcommands access all cores (typically the *\-set commands), some only
+Some commands access all cores (typically the *\-set commands), some only
 the first core (typically the *\-info commands) by default.
 
 The syntax for <cpulist> is based on how the kernel exports CPU bitmasks via
diff --git a/tools/power/cpupower/utils/builtin.h b/tools/power/cpupower/utils/builtin.h
index c870ffba5219..c10496fbe3c6 100644
--- a/tools/power/cpupower/utils/builtin.h
+++ b/tools/power/cpupower/utils/builtin.h
@@ -8,11 +8,4 @@ extern int cmd_freq_info(int argc, const char **argv);
 extern int cmd_idle_info(int argc, const char **argv);
 extern int cmd_monitor(int argc, const char **argv);
 
-extern void set_help(void);
-extern void info_help(void);
-extern void freq_set_help(void);
-extern void freq_info_help(void);
-extern void idle_info_help(void);
-extern void monitor_help(void);
-
 #endif
diff --git a/tools/power/cpupower/utils/cpufreq-info.c b/tools/power/cpupower/utils/cpufreq-info.c
index 5a1d25f056b3..28953c9a7bd5 100644
--- a/tools/power/cpupower/utils/cpufreq-info.c
+++ b/tools/power/cpupower/utils/cpufreq-info.c
@@ -510,37 +510,6 @@ static int get_latency(unsigned int cpu, unsigned int human)
         return 0;
 }
 
-void freq_info_help(void)
-{
-        printf(_("Usage: cpupower freqinfo [options]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -e, --debug          Prints out debug information [default]\n"));
-        printf(_("  -f, --freq           Get frequency the CPU currently runs at, according\n"
-               "                       to the cpufreq core *\n"));
-        printf(_("  -w, --hwfreq         Get frequency the CPU currently runs at, by reading\n"
-               "                       it from hardware (only available to root) *\n"));
-        printf(_("  -l, --hwlimits       Determine the minimum and maximum CPU frequency allowed *\n"));
-        printf(_("  -d, --driver         Determines the used cpufreq kernel driver *\n"));
-        printf(_("  -p, --policy         Gets the currently used cpufreq policy *\n"));
-        printf(_("  -g, --governors      Determines available cpufreq governors *\n"));
-        printf(_("  -r, --related-cpus   Determines which CPUs run at the same hardware frequency *\n"));
-        printf(_("  -a, --affected-cpus  Determines which CPUs need to have their frequency\n"
-                        "                       coordinated by software *\n"));
-        printf(_("  -s, --stats          Shows cpufreq statistics if available\n"));
-        printf(_("  -y, --latency        Determines the maximum latency on CPU frequency changes *\n"));
-        printf(_("  -b, --boost          Checks for turbo or boost modes  *\n"));
-        printf(_("  -o, --proc           Prints out information like provided by the /proc/cpufreq\n"
-               "                       interface in 2.4. and early 2.6. kernels\n"));
-        printf(_("  -m, --human          human-readable output for the -f, -w, -s and -y parameters\n"));
-        printf(_("  -h, --help           Prints out this screen\n"));
-
-        printf("\n");
-        printf(_("If no argument is given, full output about\n"
-               "cpufreq is printed which is useful e.g. for reporting bugs.\n\n"));
-        printf(_("By default info of CPU 0 is shown which can be overridden\n"
-                 "with the cpupower --cpu main command option.\n"));
-}
-
 static struct option info_opts[] = {
         { .name = "debug",      .has_arg = no_argument,         .flag = NULL,   .val = 'e'},
         { .name = "boost",      .has_arg = no_argument,         .flag = NULL,   .val = 'b'},
@@ -556,7 +525,6 @@ static struct option info_opts[] = {
         { .name = "latency",    .has_arg = no_argument,         .flag = NULL,   .val = 'y'},
         { .name = "proc",       .has_arg = no_argument,         .flag = NULL,   .val = 'o'},
         { .name = "human",      .has_arg = no_argument,         .flag = NULL,   .val = 'm'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
@@ -570,16 +538,12 @@ int cmd_freq_info(int argc, char **argv)
         int output_param = 0;
 
         do {
-                ret = getopt_long(argc, argv, "hoefwldpgrasmyb", info_opts, NULL);
+                ret = getopt_long(argc, argv, "oefwldpgrasmyb", info_opts, NULL);
                 switch (ret) {
                 case '?':
                         output_param = '?';
                         cont = 0;
                         break;
-                case 'h':
-                        output_param = 'h';
-                        cont = 0;
-                        break;
                 case -1:
                         cont = 0;
                         break;
@@ -642,11 +606,7 @@ int cmd_freq_info(int argc, char **argv)
                 return -EINVAL;
         case '?':
                 printf(_("invalid or unknown argument\n"));
-                freq_info_help();
                 return -EINVAL;
-        case 'h':
-                freq_info_help();
-                return EXIT_SUCCESS;
         case 'o':
                 proc_cpufreq_output();
                 return EXIT_SUCCESS;
diff --git a/tools/power/cpupower/utils/cpufreq-set.c b/tools/power/cpupower/utils/cpufreq-set.c
index 5f783622bf31..dd1539eb8c63 100644
--- a/tools/power/cpupower/utils/cpufreq-set.c
+++ b/tools/power/cpupower/utils/cpufreq-set.c
@@ -20,34 +20,11 @@
 
 #define NORM_FREQ_LEN 32
 
-void freq_set_help(void)
-{
-        printf(_("Usage: cpupower frequency-set [options]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -d FREQ, --min FREQ      new minimum CPU frequency the governor may select\n"));
-        printf(_("  -u FREQ, --max FREQ      new maximum CPU frequency the governor may select\n"));
-        printf(_("  -g GOV, --governor GOV   new cpufreq governor\n"));
-        printf(_("  -f FREQ, --freq FREQ     specific frequency to be set. Requires userspace\n"
-               "                           governor to be available and loaded\n"));
-        printf(_("  -r, --related            Switches all hardware-related CPUs\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf("\n");
-        printf(_("Notes:\n"
-               "1. Omitting the -c or --cpu argument is equivalent to setting it to \"all\"\n"));
-        printf(_("2. The -f FREQ, --freq FREQ parameter cannot be combined with any other parameter\n"
-               "   except the -c CPU, --cpu CPU parameter\n"
-               "3. FREQuencies can be passed in Hz, kHz (default), MHz, GHz, or THz\n"
-               "   by postfixing the value with the wanted unit name, without any space\n"
-               "   (FREQuency in kHz =^ Hz * 0.001 =^ MHz * 1000 =^ GHz * 1000000).\n"));
-
-}
-
 static struct option set_opts[] = {
         { .name = "min",        .has_arg = required_argument,   .flag = NULL,   .val = 'd'},
         { .name = "max",        .has_arg = required_argument,   .flag = NULL,   .val = 'u'},
         { .name = "governor",   .has_arg = required_argument,   .flag = NULL,   .val = 'g'},
         { .name = "freq",       .has_arg = required_argument,   .flag = NULL,   .val = 'f'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { .name = "related",    .has_arg = no_argument,         .flag = NULL,   .val='r'},
         { },
 };
@@ -80,7 +57,6 @@ const struct freq_units def_units[] = {
 static void print_unknown_arg(void)
 {
         printf(_("invalid or unknown argument\n"));
-        freq_set_help();
 }
 
 static unsigned long string_to_frequency(const char *str)
@@ -231,14 +207,11 @@ int cmd_freq_set(int argc, char **argv)
 
         /* parameter parsing */
         do {
-                ret = getopt_long(argc, argv, "d:u:g:f:hr", set_opts, NULL);
+                ret = getopt_long(argc, argv, "d:u:g:f:r", set_opts, NULL);
                 switch (ret) {
                 case '?':
                         print_unknown_arg();
                         return -EINVAL;
-                case 'h':
-                        freq_set_help();
-                        return 0;
                 case -1:
                         cont = 0;
                         break;
diff --git a/tools/power/cpupower/utils/cpuidle-info.c b/tools/power/cpupower/utils/cpuidle-info.c
index 70da3574f1e9..b028267c1376 100644
--- a/tools/power/cpupower/utils/cpuidle-info.c
+++ b/tools/power/cpupower/utils/cpuidle-info.c
@@ -139,30 +139,14 @@ static void proc_cpuidle_cpu_output(unsigned int cpu)
         }
 }
 
-/* --freq / -f */
-
-void idle_info_help(void)
-{
-        printf(_ ("Usage: cpupower idleinfo [options]\n"));
-        printf(_ ("Options:\n"));
-        printf(_ ("  -s, --silent         Only show general C-state information\n"));
-        printf(_ ("  -o, --proc           Prints out information like provided by the /proc/acpi/processor/*/power\n"
-               "                       interface in older kernels\n"));
-        printf(_ ("  -h, --help           Prints out this screen\n"));
-
-        printf("\n");
-}
-
 static struct option info_opts[] = {
         { .name = "silent",     .has_arg = no_argument, .flag = NULL,   .val = 's'},
         { .name = "proc",       .has_arg = no_argument, .flag = NULL,   .val = 'o'},
-        { .name = "help",       .has_arg = no_argument, .flag = NULL,   .val = 'h'},
         { },
 };
 
 static inline void cpuidle_exit(int fail)
 {
-        idle_info_help();
         exit(EXIT_FAILURE);
 }
 
@@ -174,7 +158,7 @@ int cmd_idle_info(int argc, char **argv)
         unsigned int cpu = 0;
 
         do {
-                ret = getopt_long(argc, argv, "hos", info_opts, NULL);
+                ret = getopt_long(argc, argv, "os", info_opts, NULL);
                 if (ret == -1)
                         break;
                 switch (ret) {
@@ -182,10 +166,6 @@ int cmd_idle_info(int argc, char **argv)
                         output_param = '?';
                         cont = 0;
                         break;
-                case 'h':
-                        output_param = 'h';
-                        cont = 0;
-                        break;
                 case 's':
                         verbose = 0;
                         break;
@@ -211,8 +191,6 @@ int cmd_idle_info(int argc, char **argv)
         case '?':
                 printf(_("invalid or unknown argument\n"));
                 cpuidle_exit(EXIT_FAILURE);
-        case 'h':
-                cpuidle_exit(EXIT_SUCCESS);
         }
 
         /* Default is: show output of CPU 0 only */
diff --git a/tools/power/cpupower/utils/cpupower-info.c b/tools/power/cpupower/utils/cpupower-info.c
index 85253cb7600e..3f68632c28c7 100644
--- a/tools/power/cpupower/utils/cpupower-info.c
+++ b/tools/power/cpupower/utils/cpupower-info.c
@@ -16,31 +16,16 @@
 #include "helpers/helpers.h"
 #include "helpers/sysfs.h"
 
-void info_help(void)
-{
-        printf(_("Usage: cpupower info [ -b ] [ -m ] [ -s ]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -b, --perf-bias    Gets CPU's power vs performance policy on some\n"
-               "                           Intel models [0-15], see manpage for details\n"));
-        printf(_("  -m, --sched-mc     Gets the kernel's multi core scheduler policy.\n"));
-        printf(_("  -s, --sched-smt    Gets the kernel's thread sibling scheduler policy.\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf(_("\nPassing no option will show all info, by default only on core 0\n"));
-        printf("\n");
-}
-
 static struct option set_opts[] = {
         { .name = "perf-bias",  .has_arg = optional_argument,   .flag = NULL,   .val = 'b'},
         { .name = "sched-mc",   .has_arg = optional_argument,   .flag = NULL,   .val = 'm'},
         { .name = "sched-smt",  .has_arg = optional_argument,   .flag = NULL,   .val = 's'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
 static void print_wrong_arg_exit(void)
 {
         printf(_("invalid or unknown argument\n"));
-        info_help();
         exit(EXIT_FAILURE);
 }
 
@@ -64,11 +49,8 @@ int cmd_info(int argc, char **argv)
         textdomain(PACKAGE);
 
         /* parameter parsing */
-        while ((ret = getopt_long(argc, argv, "msbh", set_opts, NULL)) != -1) {
+        while ((ret = getopt_long(argc, argv, "msb", set_opts, NULL)) != -1) {
                 switch (ret) {
-                case 'h':
-                        info_help();
-                        return 0;
                 case 'b':
                         if (params.perf_bias)
                                 print_wrong_arg_exit();
diff --git a/tools/power/cpupower/utils/cpupower-set.c b/tools/power/cpupower/utils/cpupower-set.c
index bc1b391e46f0..dc4de3762111 100644
--- a/tools/power/cpupower/utils/cpupower-set.c
+++ b/tools/power/cpupower/utils/cpupower-set.c
@@ -17,30 +17,16 @@
 #include "helpers/sysfs.h"
 #include "helpers/bitmask.h"
 
-void set_help(void)
-{
-        printf(_("Usage: cpupower set [ -b val ] [ -m val ] [ -s val ]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -b, --perf-bias [VAL]    Sets CPU's power vs performance policy on some\n"
-               "                           Intel models [0-15], see manpage for details\n"));
-        printf(_("  -m, --sched-mc  [VAL]    Sets the kernel's multi core scheduler policy.\n"));
-        printf(_("  -s, --sched-smt [VAL]    Sets the kernel's thread sibling scheduler policy.\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf("\n");
-}
-
 static struct option set_opts[] = {
         { .name = "perf-bias",  .has_arg = optional_argument,   .flag = NULL,   .val = 'b'},
         { .name = "sched-mc",   .has_arg = optional_argument,   .flag = NULL,   .val = 'm'},
         { .name = "sched-smt",  .has_arg = optional_argument,   .flag = NULL,   .val = 's'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
 static void print_wrong_arg_exit(void)
 {
         printf(_("invalid or unknown argument\n"));
-        set_help();
         exit(EXIT_FAILURE);
 }
 
@@ -66,12 +52,9 @@ int cmd_set(int argc, char **argv)
 
         params.params = 0;
         /* parameter parsing */
-        while ((ret = getopt_long(argc, argv, "m:s:b:h",
+        while ((ret = getopt_long(argc, argv, "m:s:b:",
                                                 set_opts, NULL)) != -1) {
                 switch (ret) {
-                case 'h':
-                        set_help();
-                        return 0;
                 case 'b':
                         if (params.perf_bias)
                                 print_wrong_arg_exit();
@@ -110,10 +93,8 @@ int cmd_set(int argc, char **argv)
                 }
         };
 
-        if (!params.params) {
-                set_help();
-                return -EINVAL;
-        }
+        if (!params.params)
+                print_wrong_arg_exit();
 
         if (params.sched_mc) {
                 ret = sysfs_set_sched("mc", sched_mc);
diff --git a/tools/power/cpupower/utils/cpupower.c b/tools/power/cpupower/utils/cpupower.c
index 5844ae0f786f..52bee591c1c5 100644
--- a/tools/power/cpupower/utils/cpupower.c
+++ b/tools/power/cpupower/utils/cpupower.c
@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "builtin.h"
 #include "helpers/helpers.h"
@@ -19,13 +20,12 @@
 struct cmd_struct {
         const char *cmd;
         int (*main)(int, const char **);
-        void (*usage)(void);
         int needs_root;
 };
 
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 
-int cmd_help(int argc, const char **argv);
+static int cmd_help(int argc, const char **argv);
 
 /* Global cpu_info object available for all binaries
  * Info only retrieved from CPU 0
@@ -44,55 +44,66 @@ int be_verbose;
 static void print_help(void);
 
 static struct cmd_struct commands[] = {
-        { "frequency-info",     cmd_freq_info,  freq_info_help, 0       },
-        { "frequency-set",      cmd_freq_set,   freq_set_help,  1       },
-        { "idle-info",          cmd_idle_info,  idle_info_help, 0       },
-        { "set",                cmd_set,        set_help,       1       },
-        { "info",               cmd_info,       info_help,      0       },
-        { "monitor",            cmd_monitor,    monitor_help,   0       },
-        { "help",               cmd_help,       print_help,     0       },
-        /*      { "bench",      cmd_bench,      NULL,           1       }, */
+        { "frequency-info",     cmd_freq_info,  0       },
+        { "frequency-set",      cmd_freq_set,   1       },
+        { "idle-info",          cmd_idle_info,  0       },
+        { "set",                cmd_set,        1       },
+        { "info",               cmd_info,       0       },
+        { "monitor",            cmd_monitor,    0       },
+        { "help",               cmd_help,       0       },
+        /*      { "bench",      cmd_bench,      1       }, */
 };
 
-int cmd_help(int argc, const char **argv)
-{
-        unsigned int i;
-
-        if (argc > 1) {
-                for (i = 0; i < ARRAY_SIZE(commands); i++) {
-                        struct cmd_struct *p = commands + i;
-                        if (strcmp(p->cmd, argv[1]))
-                                continue;
-                        if (p->usage) {
-                                p->usage();
-                                return EXIT_SUCCESS;
-                        }
-                }
-        }
-        print_help();
-        if (argc == 1)
-                return EXIT_SUCCESS; /* cpupower help */
-        return EXIT_FAILURE;
-}
-
 static void print_help(void)
 {
         unsigned int i;
 
 #ifdef DEBUG
-        printf(_("cpupower [ -d ][ -c cpulist ] subcommand [ARGS]\n"));
-        printf(_("  -d, --debug      May increase output (stderr) on some subcommands\n"));
+        printf(_("Usage:\tcpupower [-d|--debug] [-c|--cpu cpulist ] <command> [<args>]\n"));
 #else
-        printf(_("cpupower [ -c cpulist ] subcommand [ARGS]\n"));
+        printf(_("Usage:\tcpupower [-c|--cpu cpulist ] <command> [<args>]\n"));
 #endif
-        printf(_("cpupower --version\n"));
-        printf(_("Supported subcommands are:\n"));
+        printf(_("Supported commands are:\n"));
         for (i = 0; i < ARRAY_SIZE(commands); i++)
                 printf("\t%s\n", commands[i].cmd);
-        printf(_("\nSome subcommands can make use of the -c cpulist option.\n"));
-        printf(_("Look at the general cpupower manpage how to use it\n"));
-        printf(_("and read up the subcommand's manpage whether it is supported.\n"));
-        printf(_("\nUse cpupower help subcommand for getting help for above subcommands.\n"));
+        printf(_("\nNot all commands can make use of the -c cpulist option.\n"));
+        printf(_("\nUse 'cpupower help <command>' for getting help for above commands.\n"));
+}
+
+static int print_man_page(const char *subpage)
+{
+        int len;
+        char *page;
+
+        len = 10; /* enough for "cpupower-" */
+        if (subpage != NULL)
+                len += strlen(subpage);
+
+        page = malloc(len);
+        if (!page)
+                return -ENOMEM;
+
+        sprintf(page, "cpupower");
+        if ((subpage != NULL) && strcmp(subpage, "help")) {
+                strcat(page, "-");
+                strcat(page, subpage);
+        }
+
+        execlp("man", "man", page, NULL);
+
+        /* should not be reached */
+        return -EINVAL;
+}
+
+static int cmd_help(int argc, const char **argv)
+{
+        if (argc > 1) {
+                print_man_page(argv[1]); /* exits within execlp() */
+                return EXIT_FAILURE;
+        }
+
+        print_help();
+        return EXIT_SUCCESS;
 }
 
 static void print_version(void)
diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index 592ee362b877..2747e738efb0 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -16,11 +16,20 @@
 #include "helpers/bitmask.h"
 
 /* Internationalization ****************************/
+#ifdef NLS
+
 #define _(String) gettext(String)
 #ifndef gettext_noop
 #define gettext_noop(String) String
 #endif
 #define N_(String) gettext_noop(String)
+
+#else /* !NLS */
+
+#define _(String) String
+#define N_(String) String
+
+#endif
 /* Internationalization ****************************/
 
 extern int run_as_root;
@@ -96,6 +105,9 @@ struct cpupower_topology {
                 int pkg;
                 int core;
                 int cpu;
+
+                /* flags */
+                unsigned int is_online:1;
         } *core_info;
 };
 
diff --git a/tools/power/cpupower/utils/helpers/sysfs.c b/tools/power/cpupower/utils/helpers/sysfs.c
index 55e2466674c6..c6343024a611 100644
--- a/tools/power/cpupower/utils/helpers/sysfs.c
+++ b/tools/power/cpupower/utils/helpers/sysfs.c
@@ -56,6 +56,56 @@ static unsigned int sysfs_write_file(const char *path,
         return (unsigned int) numwrite;
 }
 
+/*
+ * Detect whether a CPU is online
+ *
+ * Returns:
+ *     1 -> if CPU is online
+ *     0 -> if CPU is offline
+ *     negative errno values in error case
+ */
+int sysfs_is_cpu_online(unsigned int cpu)
+{
+        char path[SYSFS_PATH_MAX];
+        int fd;
+        ssize_t numread;
+        unsigned long long value;
+        char linebuf[MAX_LINE_LEN];
+        char *endp;
+        struct stat statbuf;
+
+        snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u", cpu);
+
+        if (stat(path, &statbuf) != 0)
+                return 0;
+
+        /*
+         * kernel without CONFIG_HOTPLUG_CPU
+         * -> cpuX directory exists, but not cpuX/online file
+         */
+        snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/online", cpu);
+        if (stat(path, &statbuf) != 0)
+                return 1;
+
+        fd = open(path, O_RDONLY);
+        if (fd == -1)
+                return -errno;
+
+        numread = read(fd, linebuf, MAX_LINE_LEN - 1);
+        if (numread < 1) {
+                close(fd);
+                return -EIO;
+        }
+        linebuf[numread] = '\0';
+        close(fd);
+
+        value = strtoull(linebuf, &endp, 0);
+        if (value > 1 || value < 0)
+                return -EINVAL;
+
+        return value;
+}
+
 /* CPUidle idlestate specific /sys/devices/system/cpu/cpuX/cpuidle/ access */
 
 /*
diff --git a/tools/power/cpupower/utils/helpers/sysfs.h b/tools/power/cpupower/utils/helpers/sysfs.h
index f9373e090637..8cb797bbceb0 100644
--- a/tools/power/cpupower/utils/helpers/sysfs.h
+++ b/tools/power/cpupower/utils/helpers/sysfs.h
@@ -7,6 +7,8 @@
 
 extern unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen);
 
+extern int sysfs_is_cpu_online(unsigned int cpu);
+
 extern unsigned long sysfs_get_idlestate_latency(unsigned int cpu,
                                                 unsigned int idlestate);
 extern unsigned long sysfs_get_idlestate_usage(unsigned int cpu,
diff --git a/tools/power/cpupower/utils/helpers/topology.c b/tools/power/cpupower/utils/helpers/topology.c
index 385ee5c7570c..4eae2c47ba48 100644
--- a/tools/power/cpupower/utils/helpers/topology.c
+++ b/tools/power/cpupower/utils/helpers/topology.c
@@ -41,6 +41,8 @@ struct cpuid_core_info {
         unsigned int pkg;
         unsigned int thread;
         unsigned int cpu;
+        /* flags */
+        unsigned int is_online:1;
 };
 
 static int __compare(const void *t1, const void *t2)
@@ -78,6 +80,8 @@ int get_cpu_topology(struct cpupower_topology *cpu_top)
                 return -ENOMEM;
         cpu_top->pkgs = cpu_top->cores = 0;
         for (cpu = 0; cpu < cpus; cpu++) {
+                cpu_top->core_info[cpu].cpu = cpu;
+                cpu_top->core_info[cpu].is_online = sysfs_is_cpu_online(cpu);
                 cpu_top->core_info[cpu].pkg =
                         sysfs_topology_read_file(cpu, "physical_package_id");
                 if ((int)cpu_top->core_info[cpu].pkg != -1 &&
@@ -85,7 +89,6 @@ int get_cpu_topology(struct cpupower_topology *cpu_top)
                         cpu_top->pkgs = cpu_top->core_info[cpu].pkg;
                 cpu_top->core_info[cpu].core =
                         sysfs_topology_read_file(cpu, "core_id");
-                cpu_top->core_info[cpu].cpu = cpu;
         }
         cpu_top->pkgs++;
 
diff --git a/tools/power/cpupower/utils/idle_monitor/cpuidle_sysfs.c b/tools/power/cpupower/utils/idle_monitor/cpuidle_sysfs.c
index d048b96a6155..bcd22a1a3970 100644
--- a/tools/power/cpupower/utils/idle_monitor/cpuidle_sysfs.c
+++ b/tools/power/cpupower/utils/idle_monitor/cpuidle_sysfs.c
@@ -134,7 +134,7 @@ static struct cpuidle_monitor *cpuidle_register(void)
         /* Assume idle state count is the same for all CPUs */
         cpuidle_sysfs_monitor.hw_states_num = sysfs_get_idlestate_count(0);
 
-        if (cpuidle_sysfs_monitor.hw_states_num == 0)
+        if (cpuidle_sysfs_monitor.hw_states_num <= 0)
                 return NULL;
 
         for (num = 0; num < cpuidle_sysfs_monitor.hw_states_num; num++) {
diff --git a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
index ba4bf068380d..0d6571e418db 100644
--- a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
+++ b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
@@ -43,6 +43,12 @@ static struct cpupower_topology cpu_top;
 /* ToDo: Document this in the manpage */
 static char range_abbr[RANGE_MAX] = { 'T', 'C', 'P', 'M', };
 
+static void print_wrong_arg_exit(void)
+{
+        printf(_("invalid or unknown argument\n"));
+        exit(EXIT_FAILURE);
+}
+
 long long timespec_diff_us(struct timespec start, struct timespec end)
 {
         struct timespec temp;
@@ -56,21 +62,6 @@ long long timespec_diff_us(struct timespec start, struct timespec end)
         return (temp.tv_sec * 1000000) + (temp.tv_nsec / 1000);
 }
 
-void monitor_help(void)
-{
-        printf(_("cpupower monitor: [-m <mon1>,[<mon2>],.. ] command\n"));
-        printf(_("cpupower monitor: [-m <mon1>,[<mon2>],.. ] [ -i interval_sec ]\n"));
-        printf(_("cpupower monitor: -l\n"));
-        printf(_("\t command: pass an arbitrary command to measure specific workload\n"));
-        printf(_("\t -i: time intervall to measure for in seconds (default 1)\n"));
-        printf(_("\t -l: list available CPU sleep monitors (for use with -m)\n"));
-        printf(_("\t -m: show specific CPU sleep monitors only (in same order)\n"));
-        printf(_("\t -h: print this help\n"));
-        printf("\n");
-        printf(_("only one of: -l, -m are allowed\nIf none of them is passed,"));
-        printf(_(" all supported monitors are shown\n"));
-}
-
 void print_n_spaces(int n)
 {
         int x;
@@ -149,6 +140,10 @@ void print_results(int topology_depth, int cpu)
         unsigned long long result;
         cstate_t s;
 
+        /* Be careful CPUs may got resorted for pkg value do not just use cpu */
+        if (!bitmask_isbitset(cpus_chosen, cpu_top.core_info[cpu].cpu))
+                return;
+
         if (topology_depth > 2)
                 printf("%4d|", cpu_top.core_info[cpu].pkg);
         if (topology_depth > 1)
@@ -190,9 +185,13 @@ void print_results(int topology_depth, int cpu)
                         }
                 }
         }
-        /* cpu offline */
-        if (cpu_top.core_info[cpu].pkg == -1 ||
-            cpu_top.core_info[cpu].core == -1) {
+        /*
+         * The monitor could still provide useful data, for example
+         * AMD HW counters partly sit in PCI config space.
+         * It's up to the monitor plug-in to check .is_online, this one
+         * is just for additional info.
+         */
+        if (!cpu_top.core_info[cpu].is_online) {
                 printf(_(" *is offline\n"));
                 return;
         } else
@@ -238,7 +237,6 @@ static void parse_monitor_param(char *param)
         if (hits == 0) {
                 printf(_("No matching monitor found in %s, "
                          "try -l option\n"), param);
-                monitor_help();
                 exit(EXIT_FAILURE);
         }
         /* Override detected/registerd monitors array with requested one */
@@ -335,37 +333,27 @@ static void cmdline(int argc, char *argv[])
         int opt;
         progname = basename(argv[0]);
 
-        while ((opt = getopt(argc, argv, "+hli:m:")) != -1) {
+        while ((opt = getopt(argc, argv, "+li:m:")) != -1) {
                 switch (opt) {
-                case 'h':
-                        monitor_help();
-                        exit(EXIT_SUCCESS);
                 case 'l':
-                        if (mode) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode)
+                                print_wrong_arg_exit();
                         mode = list;
                         break;
                 case 'i':
                         /* only allow -i with -m or no option */
-                        if (mode && mode != show) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode && mode != show)
+                                print_wrong_arg_exit();
                         interval = atoi(optarg);
                         break;
                 case 'm':
-                        if (mode) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode)
+                                print_wrong_arg_exit();
                         mode = show;
                         show_monitors_param = optarg;
                         break;
                 default:
-                        monitor_help();
-                        exit(EXIT_FAILURE);
+                        print_wrong_arg_exit();
                 }
         }
         if (!mode)
@@ -385,6 +373,10 @@ int cmd_monitor(int argc, char **argv)
                 return EXIT_FAILURE;
         }
 
+        /* Default is: monitor all CPUs */
+        if (bitmask_isallclear(cpus_chosen))
+                bitmask_setall(cpus_chosen);
+
         dprint("System has up to %d CPU cores\n", cpu_count);
 
         for (num = 0; all_monitors[num]; num++) {
diff --git a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
index 63ca87a05e5f..5650ab5a2c20 100644
--- a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
+++ b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c
@@ -22,12 +22,15 @@
 
 #define MSR_TSC 0x10
 
+#define MSR_AMD_HWCR 0xc0010015
+
 enum mperf_id { C0 = 0, Cx, AVG_FREQ, MPERF_CSTATE_COUNT };
 
 static int mperf_get_count_percent(unsigned int self_id, double *percent,
                                    unsigned int cpu);
 static int mperf_get_count_freq(unsigned int id, unsigned long long *count,
                                 unsigned int cpu);
+static struct timespec time_start, time_end;
 
 static cstate_t mperf_cstates[MPERF_CSTATE_COUNT] = {
         {
@@ -54,19 +57,33 @@ static cstate_t mperf_cstates[MPERF_CSTATE_COUNT] = {
         },
 };
 
+enum MAX_FREQ_MODE { MAX_FREQ_SYSFS, MAX_FREQ_TSC_REF };
+static int max_freq_mode;
+/*
+ * The max frequency mperf is ticking at (in C0), either retrieved via:
+ *   1) calculated after measurements if we know TSC ticks at mperf/P0 frequency
+ *   2) cpufreq /sys/devices/.../cpu0/cpufreq/cpuinfo_max_freq at init time
+ * 1. Is preferred as it also works without cpufreq subsystem (e.g. on Xen)
+ */
+static unsigned long max_frequency;
+
 static unsigned long long tsc_at_measure_start;
 static unsigned long long tsc_at_measure_end;
-static unsigned long max_frequency;
 static unsigned long long *mperf_previous_count;
 static unsigned long long *aperf_previous_count;
 static unsigned long long *mperf_current_count;
 static unsigned long long *aperf_current_count;
+
 /* valid flag for all CPUs. If a MSR read failed it will be zero */
 static int *is_valid;
 
 static int mperf_get_tsc(unsigned long long *tsc)
 {
-        return read_msr(0, MSR_TSC, tsc);
+        int ret;
+        ret = read_msr(0, MSR_TSC, tsc);
+        if (ret)
+                dprint("Reading TSC MSR failed, returning %llu\n", *tsc);
+        return ret;
 }
 
 static int mperf_init_stats(unsigned int cpu)
@@ -97,36 +114,11 @@ static int mperf_measure_stats(unsigned int cpu)
         return 0;
 }
 
-/*
- * get_average_perf()
- *
- * Returns the average performance (also considers boosted frequencies)
- *
- * Input:
- *   aperf_diff: Difference of the aperf register over a time period
- *   mperf_diff: Difference of the mperf register over the same time period
- *   max_freq:   Maximum frequency (P0)
- *
- * Returns:
- *   Average performance over the time period
- */
-static unsigned long get_average_perf(unsigned long long aperf_diff,
-                                      unsigned long long mperf_diff)
-{
-        unsigned int perf_percent = 0;
-        if (((unsigned long)(-1) / 100) < aperf_diff) {
-                int shift_count = 7;
-                aperf_diff >>= shift_count;
-                mperf_diff >>= shift_count;
-        }
-        perf_percent = (aperf_diff * 100) / mperf_diff;
-        return (max_frequency * perf_percent) / 100;
-}
-
 static int mperf_get_count_percent(unsigned int id, double *percent,
                                    unsigned int cpu)
 {
         unsigned long long aperf_diff, mperf_diff, tsc_diff;
+        unsigned long long timediff;
 
         if (!is_valid[cpu])
                 return -1;
@@ -136,11 +128,19 @@ static int mperf_get_count_percent(unsigned int id, double *percent,
 
         mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu];
         aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu];
-        tsc_diff = tsc_at_measure_end - tsc_at_measure_start;
 
-        *percent = 100.0 * mperf_diff / tsc_diff;
-        dprint("%s: mperf_diff: %llu, tsc_diff: %llu\n",
-               mperf_cstates[id].name, mperf_diff, tsc_diff);
+        if (max_freq_mode == MAX_FREQ_TSC_REF) {
+                tsc_diff = tsc_at_measure_end - tsc_at_measure_start;
+                *percent = 100.0 * mperf_diff / tsc_diff;
+                dprint("%s: TSC Ref - mperf_diff: %llu, tsc_diff: %llu\n",
+                       mperf_cstates[id].name, mperf_diff, tsc_diff);
+        } else if (max_freq_mode == MAX_FREQ_SYSFS) {
+                timediff = timespec_diff_us(time_start, time_end);
+                *percent = 100.0 * mperf_diff / timediff;
+                dprint("%s: MAXFREQ - mperf_diff: %llu, time_diff: %llu\n",
+                       mperf_cstates[id].name, mperf_diff, timediff);
+        } else
+                return -1;
 
         if (id == Cx)
                 *percent = 100.0 - *percent;
@@ -154,7 +154,7 @@ static int mperf_get_count_percent(unsigned int id, double *percent,
 static int mperf_get_count_freq(unsigned int id, unsigned long long *count,
                                 unsigned int cpu)
 {
-        unsigned long long aperf_diff, mperf_diff;
+        unsigned long long aperf_diff, mperf_diff, time_diff, tsc_diff;
 
         if (id != AVG_FREQ)
                 return 1;
@@ -165,11 +165,21 @@ static int mperf_get_count_freq(unsigned int id, unsigned long long *count,
         mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu];
         aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu];
 
-        /* Return MHz for now, might want to return KHz if column width is more
-           generic */
-        *count = get_average_perf(aperf_diff, mperf_diff) / 1000;
-        dprint("%s: %llu\n", mperf_cstates[id].name, *count);
+        if (max_freq_mode == MAX_FREQ_TSC_REF) {
+                /* Calculate max_freq from TSC count */
+                tsc_diff = tsc_at_measure_end - tsc_at_measure_start;
+                time_diff = timespec_diff_us(time_start, time_end);
+                max_frequency = tsc_diff / time_diff;
+        }
 
+        *count = max_frequency * ((double)aperf_diff / mperf_diff);
+        dprint("%s: Average freq based on %s maximum frequency:\n",
+               mperf_cstates[id].name,
+               (max_freq_mode == MAX_FREQ_TSC_REF) ? "TSC calculated" : "sysfs read");
+        dprint("%max_frequency: %lu", max_frequency);
+        dprint("aperf_diff: %llu\n", aperf_diff);
+        dprint("mperf_diff: %llu\n", mperf_diff);
+        dprint("avg freq:   %llu\n", *count);
         return 0;
 }
 
@@ -178,6 +188,7 @@ static int mperf_start(void)
         int cpu;
         unsigned long long dbg;
 
+        clock_gettime(CLOCK_REALTIME, &time_start);
         mperf_get_tsc(&tsc_at_measure_start);
 
         for (cpu = 0; cpu < cpu_count; cpu++)
@@ -193,32 +204,104 @@ static int mperf_stop(void)
         unsigned long long dbg;
         int cpu;
 
-        mperf_get_tsc(&tsc_at_measure_end);
-
         for (cpu = 0; cpu < cpu_count; cpu++)
                 mperf_measure_stats(cpu);
 
+        mperf_get_tsc(&tsc_at_measure_end);
+        clock_gettime(CLOCK_REALTIME, &time_end);
+
         mperf_get_tsc(&dbg);
         dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end);
 
         return 0;
 }
 
-struct cpuidle_monitor mperf_monitor;
-
-struct cpuidle_monitor *mperf_register(void)
+/*
+ * Mperf register is defined to tick at P0 (maximum) frequency
+ *
+ * Instead of reading out P0 which can be tricky to read out from HW,
+ * we use TSC counter if it reliably ticks at P0/mperf frequency.
+ *
+ * Still try to fall back to:
+ * /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
+ * on older Intel HW without invariant TSC feature.
+ * Or on AMD machines where TSC does not tick at P0 (do not exist yet, but
+ * it's still double checked (MSR_AMD_HWCR)).
+ *
+ * On these machines the user would still get useful mperf
+ * stats when acpi-cpufreq driver is loaded.
+ */
+static int init_maxfreq_mode(void)
 {
+        int ret;
+        unsigned long long hwcr;
         unsigned long min;
 
-        if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF))
-                return NULL;
-
-        /* Assume min/max all the same on all cores */
+        if (!cpupower_cpu_info.caps & CPUPOWER_CAP_INV_TSC)
+                goto use_sysfs;
+
+        if (cpupower_cpu_info.vendor == X86_VENDOR_AMD) {
+                /* MSR_AMD_HWCR tells us whether TSC runs at P0/mperf
+                 * freq.
+                 * A test whether hwcr is accessable/available would be:
+                 * (cpupower_cpu_info.family > 0x10 ||
+                 *   cpupower_cpu_info.family == 0x10 &&
+                 *   cpupower_cpu_info.model >= 0x2))
+                 * This should be the case for all aperf/mperf
+                 * capable AMD machines and is therefore safe to test here.
+                 * Compare with Linus kernel git commit: acf01734b1747b1ec4
+                 */
+                ret = read_msr(0, MSR_AMD_HWCR, &hwcr);
+                /*
+                 * If the MSR read failed, assume a Xen system that did
+                 * not explicitly provide access to it and assume TSC works
+                */
+                if (ret != 0) {
+                        dprint("TSC read 0x%x failed - assume TSC working\n",
+                               MSR_AMD_HWCR);
+                        return 0;
+                } else if (1 & (hwcr >> 24)) {
+                        max_freq_mode = MAX_FREQ_TSC_REF;
+                        return 0;
+                } else { /* Use sysfs max frequency if available */ }
+        } else if (cpupower_cpu_info.vendor == X86_VENDOR_INTEL) {
+                /*
+                 * On Intel we assume mperf (in C0) is ticking at same
+                 * rate than TSC
+                 */
+                max_freq_mode = MAX_FREQ_TSC_REF;
+                return 0;
+        }
+use_sysfs:
         if (cpufreq_get_hardware_limits(0, &min, &max_frequency)) {
                 dprint("Cannot retrieve max freq from cpufreq kernel "
                        "subsystem\n");
-                return NULL;
+                return -1;
         }
+        max_freq_mode = MAX_FREQ_SYSFS;
+        return 0;
+}
+
+/*
+ * This monitor provides:
+ *
+ * 1) Average frequency a CPU resided in
+ *    This always works if the CPU has aperf/mperf capabilities
+ *
+ * 2) C0 and Cx (any sleep state) time a CPU resided in
+ *    Works if mperf timer stops ticking in sleep states which
+ *    seem to be the case on all current HW.
+ * Both is directly retrieved from HW registers and is independent
+ * from kernel statistics.
+ */
+struct cpuidle_monitor mperf_monitor;
+struct cpuidle_monitor *mperf_register(void)
+{
+        if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF))
+                return NULL;
+
+        if (init_maxfreq_mode())
+                return NULL;
 
         /* Free this at program termination */
         is_valid = calloc(cpu_count, sizeof(int));