Merge commit 'tip/perfcounters/core' into perf-counters-for-linus

8 files changed, 304 insertions, 103 deletions

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 8aa3f8c88707..e72e93110782 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -24,6 +24,9 @@ OPTIONS
 --dsos=::
         Only consider symbols in these dsos. CSV that understands
         file://filename entries.
+-n
+--show-nr-samples
+        Show the number of samples for each symbol
 -C::
 --comms=::
         Only consider symbols in these comms. CSV that understands
@@ -33,6 +36,18 @@ OPTIONS
         Only consider these symbols. CSV that understands
         file://filename entries.
 
+-w::
+--field-width=::
+        Force each column width to the provided list, for large terminal
+        readability.
+
+-t::
+--field-separator=::
+
+        Use a special separator character and don't pad with spaces, replacing
+        all occurances of this separator in symbol names (and other output)
+        with a '.' character, that thus it's the only non valid separator.
+
 SEE ALSO
 --------
 linkperf:perf-stat[1]
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 4b980cce7055..a118bc77286d 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -33,8 +33,10 @@ static char		*vmlinux = NULL;
 
 static char             default_sort_order[] = "comm,dso";
 static char             *sort_order = default_sort_order;
-static char             *dso_list_str, *comm_list_str, *sym_list_str;
+static char             *dso_list_str, *comm_list_str, *sym_list_str,
+                        *col_width_list_str;
 static struct strlist   *dso_list, *comm_list, *sym_list;
+static char             *field_sep;
 
 static int              input;
 static int              show_mask = SHOW_KERNEL | SHOW_USER | SHOW_HV;
@@ -49,6 +51,7 @@ static int		verbose;
 static int              modules;
 
 static int              full_paths;
+static int              show_nr_samples;
 
 static unsigned long    page_size;
 static unsigned long    mmap_window = 32;
@@ -129,6 +132,33 @@ typedef union event_union {
         struct read_event               read;
 } event_t;
 
+static int repsep_fprintf(FILE *fp, const char *fmt, ...)
+{
+        int n;
+        va_list ap;
+
+        va_start(ap, fmt);
+        if (!field_sep)
+                n = vfprintf(fp, fmt, ap);
+        else {
+                char *bf = NULL;
+                n = vasprintf(&bf, fmt, ap);
+                if (n > 0) {
+                        char *sep = bf;
+                        while (1) {
+                                sep = strchr(sep, *field_sep);
+                                if (sep == NULL)
+                                        break;
+                                *sep = '.';
+                        }
+                }
+                fputs(bf, fp);
+                free(bf);
+        }
+        va_end(ap);
+        return n;
+}
+
 static LIST_HEAD(dsos);
 static struct dso *kernel_dso;
 static struct dso *vdso;
@@ -360,12 +390,28 @@ static struct thread *thread__new(pid_t pid)
         return self;
 }
 
+static unsigned int dsos__col_width,
+                    comms__col_width,
+                    threads__col_width;
+
 static int thread__set_comm(struct thread *self, const char *comm)
 {
         if (self->comm)
                 free(self->comm);
         self->comm = strdup(comm);
-        return self->comm ? 0 : -ENOMEM;
+        if (!self->comm)
+                return -ENOMEM;
+
+        if (!col_width_list_str && !field_sep &&
+            (!comm_list || strlist__has_entry(comm_list, comm))) {
+                unsigned int slen = strlen(comm);
+                if (slen > comms__col_width) {
+                        comms__col_width = slen;
+                        threads__col_width = slen + 6;
+                }
+        }
+
+        return 0;
 }
 
 static size_t thread__fprintf(struct thread *self, FILE *fp)
@@ -536,7 +582,9 @@ struct sort_entry {
 
         int64_t (*cmp)(struct hist_entry *, struct hist_entry *);
         int64_t (*collapse)(struct hist_entry *, struct hist_entry *);
-        size_t  (*print)(FILE *fp, struct hist_entry *);
+        size_t  (*print)(FILE *fp, struct hist_entry *, unsigned int width);
+        unsigned int *width;
+        bool    elide;
 };
 
 static int64_t cmp_null(void *l, void *r)
@@ -558,15 +606,17 @@ sort__thread_cmp(struct hist_entry *left, struct hist_entry *right)
 }
 
 static size_t
-sort__thread_print(FILE *fp, struct hist_entry *self)
+sort__thread_print(FILE *fp, struct hist_entry *self, unsigned int width)
 {
-        return fprintf(fp, "%16s:%5d", self->thread->comm ?: "", self->thread->pid);
+        return repsep_fprintf(fp, "%*s:%5d", width - 6,
+                              self->thread->comm ?: "", self->thread->pid);
 }
 
 static struct sort_entry sort_thread = {
-        .header = "         Command:  Pid",
+        .header = "Command:  Pid",
         .cmp    = sort__thread_cmp,
         .print  = sort__thread_print,
+        .width  = &threads__col_width,
 };
 
 /* --sort comm */
@@ -590,16 +640,17 @@ sort__comm_collapse(struct hist_entry *left, struct hist_entry *right)
 }
 
 static size_t
-sort__comm_print(FILE *fp, struct hist_entry *self)
+sort__comm_print(FILE *fp, struct hist_entry *self, unsigned int width)
 {
-        return fprintf(fp, "%16s", self->thread->comm);
+        return repsep_fprintf(fp, "%*s", width, self->thread->comm);
 }
 
 static struct sort_entry sort_comm = {
-        .header         = "         Command",
+        .header         = "Command",
         .cmp            = sort__comm_cmp,
         .collapse       = sort__comm_collapse,
         .print          = sort__comm_print,
+        .width          = &comms__col_width,
 };
 
 /* --sort dso */
@@ -617,18 +668,19 @@ sort__dso_cmp(struct hist_entry *left, struct hist_entry *right)
 }
 
 static size_t
-sort__dso_print(FILE *fp, struct hist_entry *self)
+sort__dso_print(FILE *fp, struct hist_entry *self, unsigned int width)
 {
         if (self->dso)
-                return fprintf(fp, "%-25s", self->dso->name);
+                return repsep_fprintf(fp, "%-*s", width, self->dso->name);
 
-        return fprintf(fp, "%016llx         ", (u64)self->ip);
+        return repsep_fprintf(fp, "%*llx", width, (u64)self->ip);
 }
 
 static struct sort_entry sort_dso = {
-        .header = "Shared Object            ",
+        .header = "Shared Object",
         .cmp    = sort__dso_cmp,
         .print  = sort__dso_print,
+        .width  = &dsos__col_width,
 };
 
 /* --sort symbol */
@@ -648,22 +700,22 @@ sort__sym_cmp(struct hist_entry *left, struct hist_entry *right)
 }
 
 static size_t
-sort__sym_print(FILE *fp, struct hist_entry *self)
+sort__sym_print(FILE *fp, struct hist_entry *self, unsigned int width __used)
 {
         size_t ret = 0;
 
         if (verbose)
-                ret += fprintf(fp, "%#018llx  ", (u64)self->ip);
+                ret += repsep_fprintf(fp, "%#018llx  ", (u64)self->ip);
 
+        ret += repsep_fprintf(fp, "[%c] ", self->level);
         if (self->sym) {
-                ret += fprintf(fp, "[%c] %s",
-                        self->dso == kernel_dso ? 'k' :
-                        self->dso == hypervisor_dso ? 'h' : '.', self->sym->name);
+                ret += repsep_fprintf(fp, "%s", self->sym->name);
 
                 if (self->sym->module)
-                        ret += fprintf(fp, "\t[%s]", self->sym->module->name);
+                        ret += repsep_fprintf(fp, "\t[%s]",
+                                             self->sym->module->name);
         } else {
-                ret += fprintf(fp, "%#016llx", (u64)self->ip);
+                ret += repsep_fprintf(fp, "%#016llx", (u64)self->ip);
         }
 
         return ret;
@@ -690,19 +742,19 @@ sort__parent_cmp(struct hist_entry *left, struct hist_entry *right)
 }
 
 static size_t
-sort__parent_print(FILE *fp, struct hist_entry *self)
+sort__parent_print(FILE *fp, struct hist_entry *self, unsigned int width)
 {
-        size_t ret = 0;
-
-        ret += fprintf(fp, "%-20s", self->parent ? self->parent->name : "[other]");
-
-        return ret;
+        return repsep_fprintf(fp, "%-*s", width,
+                              self->parent ? self->parent->name : "[other]");
 }
 
+static unsigned int parent_symbol__col_width;
+
 static struct sort_entry sort_parent = {
-        .header = "Parent symbol       ",
+        .header = "Parent symbol",
         .cmp    = sort__parent_cmp,
         .print  = sort__parent_print,
+        .width  = &parent_symbol__col_width,
 };
 
 static int sort__need_collapse = 0;
@@ -967,17 +1019,25 @@ hist_entry__fprintf(FILE *fp, struct hist_entry *self, u64 total_samples)
                 return 0;
 
         if (total_samples)
-                ret = percent_color_fprintf(fp, "   %6.2f%%",
-                                (self->count * 100.0) / total_samples);
+                ret = percent_color_fprintf(fp,
+                                            field_sep ? "%.2f" : "   %6.2f%%",
+                                        (self->count * 100.0) / total_samples);
         else
-                ret = fprintf(fp, "%12Ld ", self->count);
+                ret = fprintf(fp, field_sep ? "%lld" : "%12lld ", self->count);
+
+        if (show_nr_samples) {
+                if (field_sep)
+                        fprintf(fp, "%c%lld", *field_sep, self->count);
+                else
+                        fprintf(fp, "%11lld", self->count);
+        }
 
         list_for_each_entry(se, &hist_entry__sort_list, list) {
-                if (exclude_other && (se == &sort_parent))
+                if (se->elide)
                         continue;
 
-                fprintf(fp, "  ");
-                ret += se->print(fp, self);
+                fprintf(fp, "%s", field_sep ?: "  ");
+                ret += se->print(fp, self, se->width ? *se->width : 0);
         }
 
         ret += fprintf(fp, "\n");
@@ -992,6 +1052,18 @@ hist_entry__fprintf(FILE *fp, struct hist_entry *self, u64 total_samples)
  *
  */
 
+static void dso__calc_col_width(struct dso *self)
+{
+        if (!col_width_list_str && !field_sep &&
+            (!dso_list || strlist__has_entry(dso_list, self->name))) {
+                unsigned int slen = strlen(self->name);
+                if (slen > dsos__col_width)
+                        dsos__col_width = slen;
+        }
+
+        self->slen_calculated = 1;
+}
+
 static struct symbol *
 resolve_symbol(struct thread *thread, struct map **mapp,
                struct dso **dsop, u64 *ipp)
@@ -1011,6 +1083,14 @@ resolve_symbol(struct thread *thread, struct map **mapp,
 
         map = thread__find_map(thread, ip);
         if (map != NULL) {
+                /*
+                 * We have to do this here as we may have a dso
+                 * with no symbol hit that has a name longer than
+                 * the ones with symbols sampled.
+                 */
+                if (!sort_dso.elide && !map->dso->slen_calculated)
+                        dso__calc_col_width(map->dso);
+
                 if (mapp)
                         *mapp = map;
 got_map:
@@ -1282,35 +1362,67 @@ static size_t output__fprintf(FILE *fp, u64 total_samples)
         struct sort_entry *se;
         struct rb_node *nd;
         size_t ret = 0;
+        unsigned int width;
+        char *col_width = col_width_list_str;
 
-        fprintf(fp, "\n");
-        fprintf(fp, "#\n");
-        fprintf(fp, "# (%Ld samples)\n", (u64)total_samples);
+        fprintf(fp, "# Samples: %Ld\n", (u64)total_samples);
         fprintf(fp, "#\n");
 
         fprintf(fp, "# Overhead");
+        if (show_nr_samples) {
+                if (field_sep)
+                        fprintf(fp, "%cSamples", *field_sep);
+                else
+                        fputs("  Samples  ", fp);
+        }
         list_for_each_entry(se, &hist_entry__sort_list, list) {
-                if (exclude_other && (se == &sort_parent))
+                if (se->elide)
+                        continue;
+                if (field_sep) {
+                        fprintf(fp, "%c%s", *field_sep, se->header);
                         continue;
-                fprintf(fp, "  %s", se->header);
+                }
+                width = strlen(se->header);
+                if (se->width) {
+                        if (col_width_list_str) {
+                                if (col_width) {
+                                        *se->width = atoi(col_width);
+                                        col_width = strchr(col_width, ',');
+                                        if (col_width)
+                                                ++col_width;
+                                }
+                        }
+                        width = *se->width = max(*se->width, width);
+                }
+                fprintf(fp, "  %*s", width, se->header);
         }
         fprintf(fp, "\n");
 
+        if (field_sep)
+                goto print_entries;
+
         fprintf(fp, "# ........");
+        if (show_nr_samples)
+                fprintf(fp, " ..........");
         list_for_each_entry(se, &hist_entry__sort_list, list) {
                 unsigned int i;
 
-                if (exclude_other && (se == &sort_parent))
+                if (se->elide)
                         continue;
 
                 fprintf(fp, "  ");
-                for (i = 0; i < strlen(se->header); i++)
+                if (se->width)
+                        width = *se->width;
+                else
+                        width = strlen(se->header);
+                for (i = 0; i < width; i++)
                         fprintf(fp, ".");
         }
         fprintf(fp, "\n");
 
         fprintf(fp, "#\n");
 
+print_entries:
         for (nd = rb_first(&output_hists); nd; nd = rb_next(nd)) {
                 pos = rb_entry(nd, struct hist_entry, rb_node);
                 ret += hist_entry__fprintf(fp, pos, total_samples);
@@ -1883,6 +1995,8 @@ static const struct option options[] = {
         OPT_STRING('k', "vmlinux", &vmlinux, "file", "vmlinux pathname"),
         OPT_BOOLEAN('m', "modules", &modules,
                     "load module symbols - WARNING: use only with -k and LIVE kernel"),
+        OPT_BOOLEAN('n', "show-nr-samples", &show_nr_samples,
+                    "Show a column with the number of samples"),
         OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
                    "sort by key(s): pid, comm, dso, symbol, parent"),
         OPT_BOOLEAN('P', "full-paths", &full_paths,
@@ -1900,6 +2014,12 @@ static const struct option options[] = {
                    "only consider symbols in these comms"),
         OPT_STRING('S', "symbols", &sym_list_str, "symbol[,symbol...]",
                    "only consider these symbols"),
+        OPT_STRING('w', "column-widths", &col_width_list_str,
+                   "width[,width...]",
+                   "don't try to adjust column width, use these fixed values"),
+        OPT_STRING('t', "field-separator", &field_sep, "separator",
+                   "separator for columns, no spaces will be added between "
+                   "columns '.' is reserved."),
         OPT_END()
 };
 
@@ -1919,7 +2039,8 @@ static void setup_sorting(void)
 }
 
 static void setup_list(struct strlist **list, const char *list_str,
-                       const char *list_name)
+                       struct sort_entry *se, const char *list_name,
+                       FILE *fp)
 {
         if (list_str) {
                 *list = strlist__new(true, list_str);
@@ -1928,6 +2049,11 @@ static void setup_list(struct strlist **list, const char *list_str,
                                 list_name);
                         exit(129);
                 }
+                if (strlist__nr_entries(*list) == 1) {
+                        fprintf(fp, "# %s: %s\n", list_name,
+                                strlist__entry(*list, 0)->s);
+                        se->elide = true;
+                }
         }
 }
 
@@ -1941,9 +2067,10 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 
         setup_sorting();
 
-        if (parent_pattern != default_parent_pattern)
+        if (parent_pattern != default_parent_pattern) {
                 sort_dimension__add("parent");
-        else
+                sort_parent.elide = 1;
+        } else
                 exclude_other = 0;
 
         /*
@@ -1952,11 +2079,17 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
         if (argc)
                 usage_with_options(report_usage, options);
 
-        setup_list(&dso_list, dso_list_str, "dso");
-        setup_list(&comm_list, comm_list_str, "comm");
-        setup_list(&sym_list, sym_list_str, "symbol");
-
         setup_pager();
 
+        setup_list(&dso_list, dso_list_str, &sort_dso, "dso", stdout);
+        setup_list(&comm_list, comm_list_str, &sort_comm, "comm", stdout);
+        setup_list(&sym_list, sym_list_str, &sort_sym, "symbol", stdout);
+
+        if (field_sep && *field_sep == '.') {
+                fputs("'.' is the only non valid --field-separator argument\n",
+                      stderr);
+                exit(129);
+        }
+
         return __cmd_report();
 }
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 27887c916439..53bb9550def9 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -1,7 +1,13 @@
 #ifndef _PERF_PERF_H
 #define _PERF_PERF_H
 
-#if defined(__x86_64__) || defined(__i386__)
+#if defined(__i386__)
+#include "../../arch/x86/include/asm/unistd.h"
+#define rmb()           asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
+#define cpu_relax()     asm volatile("rep; nop" ::: "memory");
+#endif
+
+#if defined(__x86_64__)
 #include "../../arch/x86/include/asm/unistd.h"
 #define rmb()           asm volatile("lfence" ::: "memory")
 #define cpu_relax()     asm volatile("rep; nop" ::: "memory");
diff --git a/tools/perf/util/include/linux/kernel.h b/tools/perf/util/include/linux/kernel.h
index 99c1b3d1edd9..a6b87390cb52 100644
--- a/tools/perf/util/include/linux/kernel.h
+++ b/tools/perf/util/include/linux/kernel.h
@@ -18,4 +18,12 @@
         (type *)((char *)__mptr - offsetof(type, member)); })
 #endif
 
+#ifndef max
+#define max(x, y) ({                            \
+        typeof(x) _max1 = (x);                  \
+        typeof(y) _max2 = (y);                  \
+        (void) (&_max1 == &_max2);              \
+        _max1 > _max2 ? _max1 : _max2; })
+#endif
+
 #endif
diff --git a/tools/perf/util/strlist.c b/tools/perf/util/strlist.c
index 025a78edfffe..7ad38171dc2b 100644
--- a/tools/perf/util/strlist.c
+++ b/tools/perf/util/strlist.c
@@ -64,6 +64,7 @@ int strlist__add(struct strlist *self, const char *new_entry)
 
         rb_link_node(&sn->rb_node, parent, p);
         rb_insert_color(&sn->rb_node, &self->entries);
+        ++self->nr_entries;
 
         return 0;
 }
@@ -155,8 +156,9 @@ struct strlist *strlist__new(bool dupstr, const char *slist)
         struct strlist *self = malloc(sizeof(*self));
 
         if (self != NULL) {
-                self->entries = RB_ROOT;
-                self->dupstr = dupstr;
+                self->entries    = RB_ROOT;
+                self->dupstr     = dupstr;
+                self->nr_entries = 0;
                 if (slist && strlist__parse_list(self, slist) != 0)
                         goto out_error;
         }
@@ -182,3 +184,17 @@ void strlist__delete(struct strlist *self)
                 free(self);
         }
 }
+
+struct str_node *strlist__entry(const struct strlist *self, unsigned int idx)
+{
+        struct rb_node *nd;
+
+        for (nd = rb_first(&self->entries); nd; nd = rb_next(nd)) {
+                struct str_node *pos = rb_entry(nd, struct str_node, rb_node);
+
+                if (!idx--)
+                        return pos;
+        }
+
+        return NULL;
+}
diff --git a/tools/perf/util/strlist.h b/tools/perf/util/strlist.h
index 2fdcfee87586..921818e44a54 100644
--- a/tools/perf/util/strlist.h
+++ b/tools/perf/util/strlist.h
@@ -11,7 +11,8 @@ struct str_node {
 
 struct strlist {
         struct rb_root entries;
-        bool dupstr;
+        unsigned int   nr_entries;
+        bool           dupstr;
 };
 
 struct strlist *strlist__new(bool dupstr, const char *slist);
@@ -21,11 +22,17 @@ void strlist__remove(struct strlist *self, struct str_node *sn);
 int strlist__load(struct strlist *self, const char *filename);
 int strlist__add(struct strlist *self, const char *str);
 
+struct str_node *strlist__entry(const struct strlist *self, unsigned int idx);
 bool strlist__has_entry(struct strlist *self, const char *entry);
 
 static inline bool strlist__empty(const struct strlist *self)
 {
-        return rb_first(&self->entries) == NULL;
+        return self->nr_entries == 0;
+}
+
+static inline unsigned int strlist__nr_entries(const struct strlist *self)
+{
+        return self->nr_entries;
 }
 
 int strlist__parse_list(struct strlist *self, const char *s);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 4683b67b5ee4..f40266b4845d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -65,6 +65,7 @@ struct dso *dso__new(const char *name, unsigned int sym_priv_size)
                 self->syms = RB_ROOT;
                 self->sym_priv_size = sym_priv_size;
                 self->find_symbol = dso__find_symbol;
+                self->slen_calculated = 0;
         }
 
         return self;
@@ -373,36 +374,61 @@ static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
              idx < nr_entries; \
              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 
-static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
-                                       GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym,
-                                       GElf_Shdr *shdr_dynsym,
-                                       size_t dynsym_idx, int verbose)
+/*
+ * We need to check if we have a .dynsym, so that we can handle the
+ * .plt, synthesizing its symbols, that aren't on the symtabs (be it
+ * .dynsym or .symtab).
+ * And always look at the original dso, not at debuginfo packages, that
+ * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
+ */
+static int dso__synthesize_plt_symbols(struct  dso *self, int verbose)
 {
         uint32_t nr_rel_entries, idx;
         GElf_Sym sym;
         u64 plt_offset;
         GElf_Shdr shdr_plt;
         struct symbol *f;
-        GElf_Shdr shdr_rel_plt;
+        GElf_Shdr shdr_rel_plt, shdr_dynsym;
         Elf_Data *reldata, *syms, *symstrs;
-        Elf_Scn *scn_plt_rel, *scn_symstrs;
+        Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
+        size_t dynsym_idx;
+        GElf_Ehdr ehdr;
         char sympltname[1024];
-        int nr = 0, symidx;
+        Elf *elf;
+        int nr = 0, symidx, fd, err = 0;
+
+        fd = open(self->name, O_RDONLY);
+        if (fd < 0)
+                goto out;
+
+        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+        if (elf == NULL)
+                goto out_close;
+
+        if (gelf_getehdr(elf, &ehdr) == NULL)
+                goto out_elf_end;
+
+        scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
+                                         ".dynsym", &dynsym_idx);
+        if (scn_dynsym == NULL)
+                goto out_elf_end;
 
-        scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
+        scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
                                           ".rela.plt", NULL);
         if (scn_plt_rel == NULL) {
-                scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
+                scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
                                                   ".rel.plt", NULL);
                 if (scn_plt_rel == NULL)
-                        return 0;
+                        goto out_elf_end;
         }
 
+        err = -1;
+
         if (shdr_rel_plt.sh_link != dynsym_idx)
-                return 0;
+                goto out_elf_end;
 
-        if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL)
-                return 0;
+        if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
+                goto out_elf_end;
 
         /*
          * Fetch the relocation section to find the indexes to the GOT
@@ -410,19 +436,19 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
          */
         reldata = elf_getdata(scn_plt_rel, NULL);
         if (reldata == NULL)
-                return -1;
+                goto out_elf_end;
 
         syms = elf_getdata(scn_dynsym, NULL);
         if (syms == NULL)
-                return -1;
+                goto out_elf_end;
 
-        scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link);
+        scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
         if (scn_symstrs == NULL)
-                return -1;
+                goto out_elf_end;
 
         symstrs = elf_getdata(scn_symstrs, NULL);
         if (symstrs == NULL)
-                return -1;
+                goto out_elf_end;
 
         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
         plt_offset = shdr_plt.sh_offset;
@@ -441,7 +467,7 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                                         sympltname, self->sym_priv_size, 0, verbose);
                         if (!f)
-                                return -1;
+                                goto out_elf_end;
 
                         dso__insert_symbol(self, f);
                         ++nr;
@@ -459,19 +485,25 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                                         sympltname, self->sym_priv_size, 0, verbose);
                         if (!f)
-                                return -1;
+                                goto out_elf_end;
 
                         dso__insert_symbol(self, f);
                         ++nr;
                 }
-        } else {
-                /*
-                 * TODO: There are still one more shdr_rel_plt.sh_type
-                 * I have to investigate, but probably should be ignored.
-                 */
         }
 
-        return nr;
+        err = 0;
+out_elf_end:
+        elf_end(elf);
+out_close:
+        close(fd);
+
+        if (err == 0)
+                return nr;
+out:
+        fprintf(stderr, "%s: problems reading %s PLT info.\n",
+                __func__, self->name);
+        return 0;
 }
 
 static int dso__load_sym(struct dso *self, int fd, const char *name,
@@ -485,9 +517,8 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
         GElf_Shdr shdr;
         Elf_Data *syms;
         GElf_Sym sym;
-        Elf_Scn *sec, *sec_dynsym, *sec_strndx;
+        Elf_Scn *sec, *sec_strndx;
         Elf *elf;
-        size_t dynsym_idx;
         int nr = 0;
 
         elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
@@ -504,32 +535,11 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
                 goto out_elf_end;
         }
 
-        /*
-         * We need to check if we have a .dynsym, so that we can handle the
-         * .plt, synthesizing its symbols, that aren't on the symtabs (be it
-         * .dynsym or .symtab)
-         */
-        sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr,
-                                         ".dynsym", &dynsym_idx);
-        if (sec_dynsym != NULL) {
-                nr = dso__synthesize_plt_symbols(self, elf, &ehdr,
-                                                 sec_dynsym, &shdr,
-                                                 dynsym_idx, verbose);
-                if (nr < 0)
-                        goto out_elf_end;
-        }
-
-        /*
-         * But if we have a full .symtab (that is a superset of .dynsym) we
-         * should add the symbols not in the .dynsyn
-         */
         sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
         if (sec == NULL) {
-                if (sec_dynsym == NULL)
+                sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
+                if (sec == NULL)
                         goto out_elf_end;
-
-                sec = sec_dynsym;
-                gelf_getshdr(sec, &shdr);
         }
 
         syms = elf_getdata(sec, NULL);
@@ -668,6 +678,11 @@ more:
         if (!ret)
                 goto more;
 
+        if (ret > 0) {
+                int nr_plt = dso__synthesize_plt_symbols(self, verbose);
+                if (nr_plt > 0)
+                        ret += nr_plt;
+        }
 out:
         free(name);
         return ret;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 7918cffb23cd..2f92b21c712d 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -25,6 +25,7 @@ struct dso {
         struct symbol    *(*find_symbol)(struct dso *, u64 ip);
         unsigned int     sym_priv_size;
         unsigned char    adjust_symbols;
+        unsigned char    slen_calculated;
         char             name[0];
 };