[Qemu-devel] [PATCH V2 1/3] block/accounting: rename struct BlockLatencyHistogram

[zhenwei pi <pizhenwei@bytedance.com>]

Rename struct BlockLatencyHistogram to BlockHistogram, and rename
related functions.
Make this struct and functions be common, they can be used widely.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/accounting.c         | 44 +++++++++++++++++++++++++++-----------------
 block/qapi.c               | 23 +++++++++++------------
 include/block/accounting.h |  8 ++++----
 3 files changed, 42 insertions(+), 33 deletions(-)

diff --git a/block/accounting.c b/block/accounting.c
index 70a3d9a426..d210a73fe9 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -94,13 +94,14 @@ void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
     cookie->type = type;
 }
 
-/* block_latency_histogram_compare_func:
+/**
+ * block_histogram_compare_func:
  * Compare @key with interval [@it[0], @it[1]).
  * Return: -1 if @key < @it[0]
  *          0 if @key in [@it[0], @it[1])
  *         +1 if @key >= @it[1]
  */
-static int block_latency_histogram_compare_func(const void *key, const void *it)
+static int block_histogram_compare_func(const void *key, const void *it)
 {
     uint64_t k = *(uint64_t *)key;
     uint64_t a = ((uint64_t *)it)[0];
@@ -109,8 +110,7 @@ static int block_latency_histogram_compare_func(const void *key, const void *it)
     return k < a ? -1 : (k < b ? 0 : 1);
 }
 
-static void block_latency_histogram_account(BlockLatencyHistogram *hist,
-                                            int64_t latency_ns)
+static void block_histogram_account(BlockHistogram *hist, int64_t val)
 {
     uint64_t *pos;
 
@@ -120,28 +120,26 @@ static void block_latency_histogram_account(BlockLatencyHistogram *hist,
     }
 
 
-    if (latency_ns < hist->boundaries[0]) {
+    if (val < hist->boundaries[0]) {
         hist->bins[0]++;
         return;
     }
 
-    if (latency_ns >= hist->boundaries[hist->nbins - 2]) {
+    if (val >= hist->boundaries[hist->nbins - 2]) {
         hist->bins[hist->nbins - 1]++;
         return;
     }
 
-    pos = bsearch(&latency_ns, hist->boundaries, hist->nbins - 2,
+    pos = bsearch(&val, hist->boundaries, hist->nbins - 2,
                   sizeof(hist->boundaries[0]),
-                  block_latency_histogram_compare_func);
+                  block_histogram_compare_func);
     assert(pos != NULL);
 
     hist->bins[pos - hist->boundaries + 1]++;
 }
 
-int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
-                                uint64List *boundaries)
+static int block_histogram_set(BlockHistogram *hist, uint64List *boundaries)
 {
-    BlockLatencyHistogram *hist = &stats->latency_histogram[type];
     uint64List *entry;
     uint64_t *ptr;
     uint64_t prev = 0;
@@ -170,15 +168,27 @@ int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
     return 0;
 }
 
+static void block_histogram_clear(BlockHistogram *hist)
+{
+    g_free(hist->bins);
+    g_free(hist->boundaries);
+    memset(hist, 0, sizeof(*hist));
+}
+
+int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
+                                uint64List *boundaries)
+{
+    BlockHistogram *hist = &stats->latency_histogram[type];
+
+    return block_histogram_set(hist, boundaries);
+}
+
 void block_latency_histograms_clear(BlockAcctStats *stats)
 {
     int i;
 
     for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
-        BlockLatencyHistogram *hist = &stats->latency_histogram[i];
-        g_free(hist->bins);
-        g_free(hist->boundaries);
-        memset(hist, 0, sizeof(*hist));
+        block_histogram_clear(&stats->latency_histogram[i]);
     }
 }
 
@@ -204,8 +214,8 @@ static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
         stats->nr_ops[cookie->type]++;
     }
 
-    block_latency_histogram_account(&stats->latency_histogram[cookie->type],
-                                    latency_ns);
+    block_histogram_account(&stats->latency_histogram[cookie->type],
+                            latency_ns);
 
     if (!failed || stats->account_failed) {
         stats->total_time_ns[cookie->type] += latency_ns;
diff --git a/block/qapi.c b/block/qapi.c
index 917435f022..9d9b2f1927 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -415,9 +415,8 @@ static uint64List *uint64_list(uint64_t *list, int size)
     return out_list;
 }
 
-static void bdrv_latency_histogram_stats(BlockLatencyHistogram *hist,
-                                         bool *not_null,
-                                         BlockLatencyHistogramInfo **info)
+static void bdrv_histogram_stats(BlockHistogram *hist, bool *not_null,
+                                 BlockLatencyHistogramInfo **info)
 {
     *not_null = hist->bins != NULL;
     if (*not_null) {
@@ -494,15 +493,15 @@ static void bdrv_query_blk_stats(BlockDeviceStats *ds, BlockBackend *blk)
             block_acct_queue_depth(ts, BLOCK_ACCT_WRITE);
     }
 
-    bdrv_latency_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_READ],
-                                 &ds->has_rd_latency_histogram,
-                                 &ds->rd_latency_histogram);
-    bdrv_latency_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_WRITE],
-                                 &ds->has_wr_latency_histogram,
-                                 &ds->wr_latency_histogram);
-    bdrv_latency_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_FLUSH],
-                                 &ds->has_flush_latency_histogram,
-                                 &ds->flush_latency_histogram);
+    bdrv_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_READ],
+                         &ds->has_rd_latency_histogram,
+                         &ds->rd_latency_histogram);
+    bdrv_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_WRITE],
+                         &ds->has_wr_latency_histogram,
+                         &ds->wr_latency_histogram);
+    bdrv_histogram_stats(&stats->latency_histogram[BLOCK_ACCT_FLUSH],
+                         &ds->has_flush_latency_histogram,
+                         &ds->flush_latency_histogram);
 }
 
 static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs,
diff --git a/include/block/accounting.h b/include/block/accounting.h
index d1f67b10dd..270fddb69c 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -46,7 +46,7 @@ struct BlockAcctTimedStats {
     QSLIST_ENTRY(BlockAcctTimedStats) entries;
 };
 
-typedef struct BlockLatencyHistogram {
+typedef struct BlockHistogram {
     /* The following histogram is represented like this:
      *
      * 5|           *
@@ -57,7 +57,7 @@ typedef struct BlockLatencyHistogram {
      *  +------------------
      *      10   50   100
      *
-     * BlockLatencyHistogram histogram = {
+     * BlockHistogram histogram = {
      *     .nbins = 4,
      *     .boundaries = {10, 50, 100},
      *     .bins = {3, 1, 5, 2},
@@ -74,7 +74,7 @@ typedef struct BlockLatencyHistogram {
     uint64_t *boundaries; /* @nbins-1 numbers here
                              (all boundaries, except 0 and +inf) */
     uint64_t *bins;
-} BlockLatencyHistogram;
+} BlockHistogram;
 
 struct BlockAcctStats {
     QemuMutex lock;
@@ -88,7 +88,7 @@ struct BlockAcctStats {
     QSLIST_HEAD(, BlockAcctTimedStats) intervals;
     bool account_invalid;
     bool account_failed;
-    BlockLatencyHistogram latency_histogram[BLOCK_MAX_IOTYPE];
+    BlockHistogram latency_histogram[BLOCK_MAX_IOTYPE];
 };
 
 typedef struct BlockAcctCookie {
-- 
2.11.0