target: increase the maximum number of buckets

[openocd.git] / src / target / target.c

diff --git a/src/target/target.c b/src/target/target.c
index d34e14418ff608b2dfe805edcc136b6cf6a684f2..ab35d6abe1903663958f39b19e966c0f69cb7ceb 100644 (file)
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -3387,24 +3387,30 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam
                        max = samples[i];
        }
 
-       int addressSpace = (max - min + 1);
+       /* max should be (largest sample + 1)
+        * Refer to binutils/gprof/hist.c (find_histogram_for_pc) */
+       max++;
+
+       int addressSpace = max - min;
        assert(addressSpace >= 2);
 
-       static const uint32_t maxBuckets = 16 * 1024; /* maximum buckets. */
-       uint32_t length = addressSpace;
-       if (length > maxBuckets)
-               length = maxBuckets;
-       int *buckets = malloc(sizeof(int)*length);
+       /* FIXME: What is the reasonable number of buckets?
+        * The profiling result will be more accurate if there are enough buckets. */
+       static const uint32_t maxBuckets = 128 * 1024; /* maximum buckets. */
+       uint32_t numBuckets = addressSpace;
+       if (numBuckets > maxBuckets)
+               numBuckets = maxBuckets;
+       int *buckets = malloc(sizeof(int) * numBuckets);
        if (buckets == NULL) {
                fclose(f);
                return;
        }
-       memset(buckets, 0, sizeof(int) * length);
+       memset(buckets, 0, sizeof(int) * numBuckets);
        for (i = 0; i < sampleNum; i++) {
                uint32_t address = samples[i];
                long long a = address - min;
-               long long b = length - 1;
-               long long c = addressSpace - 1;
+               long long b = numBuckets;
+               long long c = addressSpace;
                int index_t = (a * b) / c; /* danger!!!! int32 overflows */
                buckets[index_t]++;
        }
@@ -3412,7 +3418,7 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam
        /* append binary memory gmon.out &profile_hist_hdr ((char*)&profile_hist_hdr + sizeof(struct gmon_hist_hdr)) */
        writeLong(f, min);                      /* low_pc */
        writeLong(f, max);                      /* high_pc */
-       writeLong(f, length);           /* # of samples */
+       writeLong(f, numBuckets);       /* # of buckets */
        writeLong(f, 100);                      /* KLUDGE! We lie, ca. 100Hz best case. */
        writeString(f, "seconds");
        for (i = 0; i < (15-strlen("seconds")); i++)
@@ -3421,9 +3427,9 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam
 
        /*append binary memory gmon.out profile_hist_data (profile_hist_data + profile_hist_hdr.hist_size) */
 
-       char *data = malloc(2 * length);
+       char *data = malloc(2 * numBuckets);
        if (data != NULL) {
-               for (i = 0; i < length; i++) {
+               for (i = 0; i < numBuckets; i++) {
                        int val;
                        val = buckets[i];
                        if (val > 65535)
@@ -3432,7 +3438,7 @@ static void writeGmon(uint32_t *samples, uint32_t sampleNum, const char *filenam
                        data[i * 2 + 1] = (val >> 8) & 0xff;
                }
                free(buckets);
-               writeData(f, data, length * 2);
+               writeData(f, data, numBuckets * 2);
                free(data);
        } else
                free(buckets);