perf_counter: Rework the sample ABI

The PERF_EVENT_READ implementation made me realize we don't
actually need the sample_type int the output sample, since
we already have that in the perf_counter_attr information.

Therefore, remove the PERF_EVENT_MISC_OVERFLOW bit and the
event->type overloading, and imply put counter overflow
samples in a PERF_EVENT_SAMPLE type.

This also fixes the issue that event->type was only 32-bit
and sample_type had 64 usable bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 49 insertions, 48 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index de70a10b5ec8..3078e23c91eb 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -262,7 +262,6 @@ struct perf_counter_mmap_page {
 #define PERF_EVENT_MISC_KERNEL                  (1 << 0)
 #define PERF_EVENT_MISC_USER                    (2 << 0)
 #define PERF_EVENT_MISC_HYPERVISOR              (3 << 0)
-#define PERF_EVENT_MISC_OVERFLOW                (1 << 2)
 
 struct perf_event_header {
         __u32   type;
@@ -348,9 +347,6 @@ enum perf_event_type {
         PERF_EVENT_READ                 = 8,
 
         /*
-         * When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
-         * will be PERF_SAMPLE_*
-         *
          * struct {
          *      struct perf_event_header        header;
          *
@@ -358,8 +354,9 @@ enum perf_event_type {
          *      { u32                   pid, tid; } && PERF_SAMPLE_TID
          *      { u64                   time;     } && PERF_SAMPLE_TIME
          *      { u64                   addr;     } && PERF_SAMPLE_ADDR
-         *      { u64                   config;   } && PERF_SAMPLE_CONFIG
+         *      { u64                   id;       } && PERF_SAMPLE_ID
          *      { u32                   cpu, res; } && PERF_SAMPLE_CPU
+         *      { u64                   period;   } && PERF_SAMPLE_PERIOD
          *
          *      { u64                   nr;
          *        { u64 id, val; }      cnt[nr];  } && PERF_SAMPLE_GROUP
@@ -368,6 +365,9 @@ enum perf_event_type {
          *        u64                   ips[nr];  } && PERF_SAMPLE_CALLCHAIN
          * };
          */
+        PERF_EVENT_SAMPLE               = 9,
+
+        PERF_EVENT_MAX,                 /* non-ABI */
 };
 
 enum perf_callchain_context {
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 385ca51c6e60..f2f232696587 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -2575,15 +2575,14 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                 u32 cpu, reserved;
         } cpu_entry;
 
-        header.type = 0;
+        header.type = PERF_EVENT_SAMPLE;
         header.size = sizeof(header);
 
-        header.misc = PERF_EVENT_MISC_OVERFLOW;
+        header.misc = 0;
         header.misc |= perf_misc_flags(data->regs);
 
         if (sample_type & PERF_SAMPLE_IP) {
                 ip = perf_instruction_pointer(data->regs);
-                header.type |= PERF_SAMPLE_IP;
                 header.size += sizeof(ip);
         }
 
@@ -2592,7 +2591,6 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                 tid_entry.pid = perf_counter_pid(counter, current);
                 tid_entry.tid = perf_counter_tid(counter, current);
 
-                header.type |= PERF_SAMPLE_TID;
                 header.size += sizeof(tid_entry);
         }
 
@@ -2602,34 +2600,25 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                  */
                 time = sched_clock();
 
-                header.type |= PERF_SAMPLE_TIME;
                 header.size += sizeof(u64);
         }
 
-        if (sample_type & PERF_SAMPLE_ADDR) {
-                header.type |= PERF_SAMPLE_ADDR;
+        if (sample_type & PERF_SAMPLE_ADDR)
                 header.size += sizeof(u64);
-        }
 
-        if (sample_type & PERF_SAMPLE_ID) {
-                header.type |= PERF_SAMPLE_ID;
+        if (sample_type & PERF_SAMPLE_ID)
                 header.size += sizeof(u64);
-        }
 
         if (sample_type & PERF_SAMPLE_CPU) {
-                header.type |= PERF_SAMPLE_CPU;
                 header.size += sizeof(cpu_entry);
 
                 cpu_entry.cpu = raw_smp_processor_id();
         }
 
-        if (sample_type & PERF_SAMPLE_PERIOD) {
-                header.type |= PERF_SAMPLE_PERIOD;
+        if (sample_type & PERF_SAMPLE_PERIOD)
                 header.size += sizeof(u64);
-        }
 
         if (sample_type & PERF_SAMPLE_GROUP) {
-                header.type |= PERF_SAMPLE_GROUP;
                 header.size += sizeof(u64) +
                         counter->nr_siblings * sizeof(group_entry);
         }
@@ -2639,10 +2628,9 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 
                 if (callchain) {
                         callchain_size = (1 + callchain->nr) * sizeof(u64);
-
-                        header.type |= PERF_SAMPLE_CALLCHAIN;
                         header.size += callchain_size;
-                }
+                } else
+                        header.size += sizeof(u64);
         }
 
         ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
@@ -2693,8 +2681,14 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
                 }
         }
 
-        if (callchain)
-                perf_output_copy(&handle, callchain, callchain_size);
+        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+                if (callchain)
+                        perf_output_copy(&handle, callchain, callchain_size);
+                else {
+                        u64 nr = 0;
+                        perf_output_put(&handle, nr);
+                }
+        }
 
         perf_output_end(&handle);
 }
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 7e58e3ad1508..722c0f54e549 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -855,7 +855,7 @@ static unsigned long total = 0,
                      total_unknown = 0;
 
 static int
-process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
+process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 {
         char level;
         int show = 0;
@@ -1013,10 +1013,10 @@ process_period_event(event_t *event, unsigned long offset, unsigned long head)
 static int
 process_event(event_t *event, unsigned long offset, unsigned long head)
 {
-        if (event->header.misc & PERF_EVENT_MISC_OVERFLOW)
-                return process_overflow_event(event, offset, head);
-
         switch (event->header.type) {
+        case PERF_EVENT_SAMPLE:
+                return process_sample_event(event, offset, head);
+
         case PERF_EVENT_MMAP:
                 return process_mmap_event(event, offset, head);
 
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index e575f3039766..ec5361c67bf5 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -53,6 +53,8 @@ static regex_t		parent_regex;
 
 static int              exclude_other = 1;
 
+static u64              sample_type;
+
 struct ip_event {
         struct perf_event_header header;
         u64 ip;
@@ -1135,7 +1137,7 @@ static int validate_chain(struct ip_callchain *chain, event_t *event)
 }
 
 static int
-process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
+process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 {
         char level;
         int show = 0;
@@ -1147,12 +1149,12 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
         void *more_data = event->ip.__more_data;
         struct ip_callchain *chain = NULL;
 
-        if (event->header.type & PERF_SAMPLE_PERIOD) {
+        if (sample_type & PERF_SAMPLE_PERIOD) {
                 period = *(u64 *)more_data;
                 more_data += sizeof(u64);
         }
 
-        dprintf("%p [%p]: PERF_EVENT (IP, %d): %d: %p period: %Ld\n",
+        dprintf("%p [%p]: PERF_EVENT_SAMPLE (IP, %d): %d: %p period: %Ld\n",
                 (void *)(offset + head),
                 (void *)(long)(event->header.size),
                 event->header.misc,
@@ -1160,7 +1162,7 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
                 (void *)(long)ip,
                 (long long)period);
 
-        if (event->header.type & PERF_SAMPLE_CALLCHAIN) {
+        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
                 int i;
 
                 chain = (void *)more_data;
@@ -1352,10 +1354,10 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
 {
         trace_event(event);
 
-        if (event->header.misc & PERF_EVENT_MISC_OVERFLOW)
-                return process_overflow_event(event, offset, head);
-
         switch (event->header.type) {
+        case PERF_EVENT_SAMPLE:
+                return process_sample_event(event, offset, head);
+
         case PERF_EVENT_MMAP:
                 return process_mmap_event(event, offset, head);
 
@@ -1388,18 +1390,21 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
 
 static struct perf_header       *header;
 
-static int perf_header__has_sample(u64 sample_mask)
+static u64 perf_header__sample_type(void)
 {
+        u64 sample_type = 0;
         int i;
 
         for (i = 0; i < header->attrs; i++) {
                 struct perf_header_attr *attr = header->attr[i];
 
-                if (!(attr->attr.sample_type & sample_mask))
-                        return 0;
+                if (!sample_type)
+                        sample_type = attr->attr.sample_type;
+                else if (sample_type != attr->attr.sample_type)
+                        die("non matching sample_type");
         }
 
-        return 1;
+        return sample_type;
 }
 
 static int __cmd_report(void)
@@ -1437,8 +1442,9 @@ static int __cmd_report(void)
         header = perf_header__read(input);
         head = header->data_offset;
 
-        if (sort__has_parent &&
-            !perf_header__has_sample(PERF_SAMPLE_CALLCHAIN)) {
+        sample_type = perf_header__sample_type();
+
+        if (sort__has_parent && !(sample_type & PERF_SAMPLE_CALLCHAIN)) {
                 fprintf(stderr, "selected --sort parent, but no callchain data\n");
                 exit(-1);
         }
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5352b5e352ed..cf0d21f1ae10 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -392,11 +392,11 @@ static void record_ip(u64 ip, int counter)
         samples--;
 }
 
-static void process_event(u64 ip, int counter)
+static void process_event(u64 ip, int counter, int user)
 {
         samples++;
 
-        if (ip < min_ip || ip > max_ip) {
+        if (user) {
                 userspace_samples++;
                 return;
         }
@@ -509,9 +509,10 @@ static void mmap_read_counter(struct mmap_data *md)
 
                 old += size;
 
-                if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
-                        if (event->header.type & PERF_SAMPLE_IP)
-                                process_event(event->ip.ip, md->counter);
+                if (event->header.type == PERF_EVENT_SAMPLE) {
+                        int user =
+        (event->header.misc & PERF_EVENT_MISC_CPUMODE_MASK) == PERF_EVENT_MISC_USER;
+                        process_event(event->ip.ip, md->counter, user);
                 }
         }