[PATCH] blkparse: add per-process stats for longest waits

diff --git a/blkparse.c b/blkparse.c
index ca4fea15e4c00c7e049bb12c85f64d79c8e1e016..77f6f5f6d7904d98bd6a85c78c1e78f5e12d2a56 100644 (file)
--- a/blkparse.c
+++ b/blkparse.c
@@ -61,6 +61,13 @@ struct per_process_info {
        __u32 pid;
        struct io_stats io_stats;
        struct per_process_info *hash_next, *list_next;
+
+       /*
+        * individual io stats
+        */
+       unsigned long long longest_allocation_wait;
+       unsigned long long longest_dispatch_wait;
+       unsigned long long longest_completion_wait;
 };
 
 #define PPI_HASH_SHIFT (8)
@@ -265,13 +272,14 @@ static struct io_track *__find_track(__u64 sector)
        return NULL;
 }
 
-static struct io_track *find_track(__u64 sector)
+static struct io_track *find_track(__u32 pid, __u64 sector)
 {
        struct io_track *iot = __find_track(sector);
 
        iot = __find_track(sector);
        if (!iot) {
                iot = malloc(sizeof(*iot));
+               iot->pid = pid;
                iot->sector = sector;
                track_rb_insert(iot);
        }
@@ -306,7 +314,7 @@ static void log_track_getrq(struct blk_io_trace *t)
        if (!track_ios)
                return;
 
-       iot = find_track(t->sector);
+       iot = find_track(t->pid, t->sector);
        iot->allocation_time = t->time;
 }
 
@@ -316,14 +324,24 @@ static void log_track_getrq(struct blk_io_trace *t)
  */
 static unsigned long long log_track_queue(struct blk_io_trace *t)
 {
+       unsigned long long elapsed;
        struct io_track *iot;
 
        if (!track_ios)
                return -1;
 
-       iot = find_track(t->sector);
+       iot = find_track(t->pid, t->sector);
        iot->queue_time = t->time;
-       return iot->queue_time - iot->allocation_time;
+       elapsed = iot->queue_time - iot->allocation_time;
+
+       if (per_process_stats) {
+               struct per_process_info *ppi = find_process_by_pid(iot->pid);
+
+               if (ppi && elapsed > ppi->longest_allocation_wait)
+                       ppi->longest_allocation_wait = elapsed;
+       }
+
+       return elapsed;
 }
 
 /*
@@ -331,6 +349,7 @@ static unsigned long long log_track_queue(struct blk_io_trace *t)
  */
 static unsigned long long log_track_issue(struct blk_io_trace *t)
 {
+       unsigned long long elapsed;
        struct io_track *iot;
 
        if (!track_ios)
@@ -345,7 +364,16 @@ static unsigned long long log_track_issue(struct blk_io_trace *t)
        }
 
        iot->dispatch_time = t->time;
-       return iot->dispatch_time - iot->queue_time;
+       elapsed = iot->dispatch_time - iot->queue_time;
+
+       if (per_process_stats) {
+               struct per_process_info *ppi = find_process_by_pid(iot->pid);
+
+               if (ppi && elapsed > ppi->longest_dispatch_wait)
+                       ppi->longest_dispatch_wait = elapsed;
+       }
+
+       return elapsed;
 }
 
 /*
@@ -370,6 +398,13 @@ static unsigned long long log_track_complete(struct blk_io_trace *t)
        iot->completion_time = t->time;
        elapsed = iot->completion_time - iot->dispatch_time;
 
+       if (per_process_stats) {
+               struct per_process_info *ppi = find_process_by_pid(iot->pid);
+
+               if (ppi && elapsed > ppi->longest_completion_wait)
+                       ppi->longest_completion_wait = elapsed;
+       }
+
        /*
         * kill the trace, we don't need it after completion
         */
@@ -774,6 +809,16 @@ static void dump_io_stats(struct io_stats *ios, char *msg)
        fprintf(ofp, " Write Merges:     %'8lu\n", ios->mwrites);
 }
 
+static void dump_wait_stats(struct per_process_info *ppi)
+{
+       double await = (double) ppi->longest_allocation_wait / 1000;
+       double dwait = (double) ppi->longest_dispatch_wait / 1000;
+       double cwait = (double) ppi->longest_completion_wait / 1000;
+
+       fprintf(ofp, " Wait: Alloc=%f, Dispatch=%f, Completion=%f\n",
+               await, dwait, cwait);
+}
+
 static void show_process_stats(void)
 {
        struct per_process_info *ppi;
@@ -781,6 +826,7 @@ static void show_process_stats(void)
        ppi = ppi_list;
        while (ppi) {
                dump_io_stats(&ppi->io_stats, ppi->name);
+               dump_wait_stats(ppi);
                ppi = ppi->list_next;
        }