oprofile: use new data sample format for ibs

The new ring buffer implementation allows the storage of samples with
different size. This patch implements the usage of the new sample
format to store ibs samples in the cpu buffer. Until now, writing to
the cpu buffer could lead to incomplete sampling sequences since IBS
samples were transfered in multiple samples. Due to a full buffer,
data could be lost at any time. This can't happen any more since the
complete data is reserved in advance and then stored in a single
sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>

1 files changed, 12 insertions, 41 deletions

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index f9031d31eeb7..d692fdc1a211 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -318,29 +318,18 @@ static void add_trace_begin(void)
 
 #ifdef CONFIG_OPROFILE_IBS
 
-#define IBS_FETCH_CODE_SIZE     2
-#define IBS_OP_CODE_SIZE        5
-
-/*
- * Add IBS fetch and op entries to event buffer
- */
-static void add_ibs_begin(int cpu, int code, struct mm_struct *mm)
+static void add_data(struct op_entry *entry, struct mm_struct *mm)
 {
-        unsigned long pc;
-        int i, count;
-        unsigned long cookie = 0;
+        unsigned long code, pc, val;
+        unsigned long cookie;
         off_t offset;
-        struct op_entry entry;
-        struct op_sample *sample;
 
-        sample = op_cpu_buffer_read_entry(&entry, cpu);
-        if (!sample)
+        if (!op_cpu_buffer_get_data(entry, &code))
+                return;
+        if (!op_cpu_buffer_get_data(entry, &pc))
+                return;
+        if (!op_cpu_buffer_get_size(entry))
                 return;
-        pc = sample->eip;
-
-#ifdef __LP64__
-        pc += sample->event << 32;
-#endif
 
         if (mm) {
                 cookie = lookup_dcookie(mm, pc, &offset);
@@ -362,24 +351,8 @@ static void add_ibs_begin(int cpu, int code, struct mm_struct *mm)
         add_event_entry(code);
         add_event_entry(offset);        /* Offset from Dcookie */
 
-        /* we send the Dcookie offset, but send the raw Linear Add also*/
-        add_event_entry(sample->eip);
-        add_event_entry(sample->event);
-
-        if (code == IBS_FETCH_CODE)
-                count = IBS_FETCH_CODE_SIZE;    /*IBS FETCH is 2 int64s*/
-        else
-                count = IBS_OP_CODE_SIZE;       /*IBS OP is 5 int64s*/
-
-        for (i = 0; i < count; i++) {
-                sample = op_cpu_buffer_read_entry(&entry, cpu);
-                if (!sample)
-                        return;
-                add_event_entry(sample->eip);
-                add_event_entry(sample->event);
-        }
-
-        return;
+        while (op_cpu_buffer_get_data(entry, &val))
+                add_event_entry(val);
 }
 
 #endif
@@ -572,10 +545,8 @@ void sync_buffer(int cpu)
                                 add_user_ctx_switch(new, cookie);
                         }
 #ifdef CONFIG_OPROFILE_IBS
-                        if (flags & IBS_FETCH_BEGIN)
-                                add_ibs_begin(cpu, IBS_FETCH_CODE, mm);
-                        if (flags & IBS_OP_BEGIN)
-                                add_ibs_begin(cpu, IBS_OP_CODE, mm);
+                        if (op_cpu_buffer_get_size(&entry))
+                                add_data(&entry, mm);
 #endif
                         continue;
                 }