1 files changed, 125 insertions, 3 deletions

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 03b7bc70eb66..d1eece70b84d 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -473,17 +473,73 @@ int symbol__alloc_hist(struct symbol *sym)
         return 0;
 }
 
+/* The cycles histogram is lazily allocated. */
+static int symbol__alloc_hist_cycles(struct symbol *sym)
+{
+        struct annotation *notes = symbol__annotation(sym);
+        const size_t size = symbol__size(sym);
+
+        notes->src->cycles_hist = calloc(size, sizeof(struct cyc_hist));
+        if (notes->src->cycles_hist == NULL)
+                return -1;
+        return 0;
+}
+
 void symbol__annotate_zero_histograms(struct symbol *sym)
 {
         struct annotation *notes = symbol__annotation(sym);
 
         pthread_mutex_lock(&notes->lock);
-        if (notes->src != NULL)
+        if (notes->src != NULL) {
                 memset(notes->src->histograms, 0,
                        notes->src->nr_histograms * notes->src->sizeof_sym_hist);
+                if (notes->src->cycles_hist)
+                        memset(notes->src->cycles_hist, 0,
+                                symbol__size(sym) * sizeof(struct cyc_hist));
+        }
         pthread_mutex_unlock(&notes->lock);
 }
 
+static int __symbol__account_cycles(struct annotation *notes,
+                                    u64 start,
+                                    unsigned offset, unsigned cycles,
+                                    unsigned have_start)
+{
+        struct cyc_hist *ch;
+
+        ch = notes->src->cycles_hist;
+        /*
+         * For now we can only account one basic block per
+         * final jump. But multiple could be overlapping.
+         * Always account the longest one. So when
+         * a shorter one has been already seen throw it away.
+         *
+         * We separately always account the full cycles.
+         */
+        ch[offset].num_aggr++;
+        ch[offset].cycles_aggr += cycles;
+
+        if (!have_start && ch[offset].have_start)
+                return 0;
+        if (ch[offset].num) {
+                if (have_start && (!ch[offset].have_start ||
+                                   ch[offset].start > start)) {
+                        ch[offset].have_start = 0;
+                        ch[offset].cycles = 0;
+                        ch[offset].num = 0;
+                        if (ch[offset].reset < 0xffff)
+                                ch[offset].reset++;
+                } else if (have_start &&
+                           ch[offset].start < start)
+                        return 0;
+        }
+        ch[offset].have_start = have_start;
+        ch[offset].start = start;
+        ch[offset].cycles += cycles;
+        ch[offset].num++;
+        return 0;
+}
+
 static int __symbol__inc_addr_samples(struct symbol *sym, struct map *map,
                                       struct annotation *notes, int evidx, u64 addr)
 {
@@ -506,7 +562,7 @@ static int __symbol__inc_addr_samples(struct symbol *sym, struct map *map,
         return 0;
 }
 
-static struct annotation *symbol__get_annotation(struct symbol *sym)
+static struct annotation *symbol__get_annotation(struct symbol *sym, bool cycles)
 {
         struct annotation *notes = symbol__annotation(sym);
 
@@ -514,6 +570,10 @@ static struct annotation *symbol__get_annotation(struct symbol *sym)
                 if (symbol__alloc_hist(sym) < 0)
                         return NULL;
         }
+        if (!notes->src->cycles_hist && cycles) {
+                if (symbol__alloc_hist_cycles(sym) < 0)
+                        return NULL;
+        }
         return notes;
 }
 
@@ -524,12 +584,73 @@ static int symbol__inc_addr_samples(struct symbol *sym, struct map *map,
 
         if (sym == NULL)
                 return 0;
-        notes = symbol__get_annotation(sym);
+        notes = symbol__get_annotation(sym, false);
         if (notes == NULL)
                 return -ENOMEM;
         return __symbol__inc_addr_samples(sym, map, notes, evidx, addr);
 }
 
+static int symbol__account_cycles(u64 addr, u64 start,
+                                  struct symbol *sym, unsigned cycles)
+{
+        struct annotation *notes;
+        unsigned offset;
+
+        if (sym == NULL)
+                return 0;
+        notes = symbol__get_annotation(sym, true);
+        if (notes == NULL)
+                return -ENOMEM;
+        if (addr < sym->start || addr >= sym->end)
+                return -ERANGE;
+
+        if (start) {
+                if (start < sym->start || start >= sym->end)
+                        return -ERANGE;
+                if (start >= addr)
+                        start = 0;
+        }
+        offset = addr - sym->start;
+        return __symbol__account_cycles(notes,
+                                        start ? start - sym->start : 0,
+                                        offset, cycles,
+                                        !!start);
+}
+
+int addr_map_symbol__account_cycles(struct addr_map_symbol *ams,
+                                    struct addr_map_symbol *start,
+                                    unsigned cycles)
+{
+        u64 saddr = 0;
+        int err;
+
+        if (!cycles)
+                return 0;
+
+        /*
+         * Only set start when IPC can be computed. We can only
+         * compute it when the basic block is completely in a single
+         * function.
+         * Special case the case when the jump is elsewhere, but
+         * it starts on the function start.
+         */
+        if (start &&
+                (start->sym == ams->sym ||
+                 (ams->sym &&
+                   start->addr == ams->sym->start + ams->map->start)))
+                saddr = start->al_addr;
+        if (saddr == 0)
+                pr_debug2("BB with bad start: addr %"PRIx64" start %"PRIx64" sym %"PRIx64" saddr %"PRIx64"\n",
+                        ams->addr,
+                        start ? start->addr : 0,
+                        ams->sym ? ams->sym->start + ams->map->start : 0,
+                        saddr);
+        err = symbol__account_cycles(ams->al_addr, saddr, ams->sym, cycles);
+        if (err)
+                pr_debug2("account_cycles failed %d\n", err);
+        return err;
+}
+
 int addr_map_symbol__inc_samples(struct addr_map_symbol *ams, int evidx)
 {
         return symbol__inc_addr_samples(ams->sym, ams->map, evidx, ams->al_addr);
@@ -1005,6 +1126,7 @@ fallback:
                 dso->annotate_warned = 1;
                 pr_err("Can't annotate %s:\n\n"
                        "No vmlinux file%s\nwas found in the path.\n\n"
+                       "Note that annotation using /proc/kcore requires CAP_SYS_RAWIO capability.\n\n"
                        "Please use:\n\n"
                        "  perf buildid-cache -vu vmlinux\n\n"
                        "or:\n\n"