[PATCH] blkparse: maintain map of online CPUs instead of open files

The ->nopenfiles fix is not enough, since it doesn't tell us if
the right CPUs are online or not.

diff --git a/blkparse.c b/blkparse.c
index a834278be127bc9d11cb9635cf24f5ea65ecff1d..ca2f28f296985cb1001ab8bc80664998c4596048 100644 (file)
--- a/blkparse.c
+++ b/blkparse.c
@@ -55,8 +55,11 @@ struct per_dev_info {
        struct rb_root rb_track;
 
        int nfiles;
-       int nopenfiles;
        int ncpus;
+
+       unsigned long *cpu_map;
+       unsigned int cpu_map_max;
+
        struct per_cpu_info *cpus;
 };
 
@@ -249,6 +252,40 @@ static volatile int done;
 
 #define JHASH_RANDOM   (0x3af5f2ee)
 
+#define CPUS_PER_LONG  (8 * sizeof(unsigned long))
+#define CPU_IDX(cpu)   ((cpu) / CPUS_PER_LONG)
+#define CPU_BIT(cpu)   ((cpu) & (CPUS_PER_LONG - 1))
+
+static void cpu_mark_online(struct per_dev_info *pdi, unsigned int cpu)
+{
+       if (cpu >= pdi->cpu_map_max || !pdi->cpu_map) {
+               int new_max = (cpu + CPUS_PER_LONG) & ~(CPUS_PER_LONG - 1);
+               unsigned long *map = malloc(new_max / sizeof(long));
+
+               memset(map, 0, new_max / sizeof(long));
+
+               if (pdi->cpu_map) {
+                       memcpy(map, pdi->cpu_map, pdi->cpu_map_max / sizeof(long));
+                       free(pdi->cpu_map);
+               }
+
+               pdi->cpu_map = map;
+               pdi->cpu_map_max = new_max;
+       }
+
+       pdi->cpu_map[CPU_IDX(cpu)] |= (1UL << CPU_BIT(cpu));
+}
+
+static inline void cpu_mark_offline(struct per_dev_info *pdi, int cpu)
+{
+       pdi->cpu_map[CPU_IDX(cpu)] &= ~(1UL << CPU_BIT(cpu));
+}
+
+static inline int cpu_is_online(struct per_dev_info *pdi, int cpu)
+{
+       return (pdi->cpu_map[CPU_IDX(cpu)] & (1UL << CPU_BIT(cpu))) != 0;
+}
+
 static inline int ppi_hash_pid(__u32 pid)
 {
        return jhash_1word(pid, JHASH_RANDOM) & PPI_HASH_MASK;
@@ -1346,6 +1383,46 @@ static void put_trace(struct per_dev_info *pdi, struct trace *t)
        }
 }
 
+/*
+ * to continue, we must have traces from all online cpus in the tree
+ */
+static int check_cpu_map(struct per_dev_info *pdi)
+{
+       unsigned long *cpu_map;
+       struct rb_node *n;
+       struct trace *__t;
+       unsigned int i;
+       int ret, cpu;
+
+       /*
+        * create a map of the cpus we have traces for
+        */
+       cpu_map = malloc(pdi->cpu_map_max / sizeof(long));
+       n = rb_first(&rb_sort_root);
+       while (n) {
+               __t = rb_entry(n, struct trace, rb_node);
+               cpu = __t->bit->cpu;
+
+               cpu_map[CPU_IDX(cpu)] |= (1UL << CPU_BIT(cpu));
+               n = rb_next(n);
+       }
+
+       /*
+        * we can't continue of pdi->cpu_map has entries set that we don't.
+        * the opposite is not a problem, though
+        */
+       ret = 0;
+       for (i = 0; i < pdi->cpu_map_max / CPUS_PER_LONG; i++) {
+               if (pdi->cpu_map[i] & ~(cpu_map[i])) {
+                       ret = 1;
+                       break;
+               }
+       }
+
+       free(cpu_map);
+       return ret;
+}
+
 static int check_sequence(struct per_dev_info *pdi, struct trace *t, int force)
 {
        unsigned long expected_sequence = pdi->last_sequence + 1;
@@ -1353,35 +1430,13 @@ static int check_sequence(struct per_dev_info *pdi, struct trace *t, int force)
        struct trace *__t;
        
        if (!expected_sequence) {
-               struct rb_node *n;
-               char *cpu_seen;
-               int cpus;
-
                /*
                 * 1 should be the first entry, just allow it
                 */
                if (bit->sequence == 1)
                        return 0;
 
-               /*
-                * if we are starting somewhere else, check that we have
-                * entries from all cpus in the tree before dumping one
-                */
-               cpu_seen = malloc(pdi->nopenfiles);
-               n = rb_first(&rb_sort_root);
-               cpus = 0;
-               while (n) {
-                       __t = rb_entry(n, struct trace, rb_node);
-
-                       if (!cpu_seen[__t->bit->cpu]) {
-                               cpu_seen[__t->bit->cpu] = 1;
-                               cpus++;
-                       }
-                       n = rb_next(n);
-               }
-
-               free(cpu_seen);
-               return cpus != pdi->nopenfiles;
+               return check_cpu_map(pdi);
        }
 
        if (bit->sequence == expected_sequence)
@@ -1587,7 +1642,7 @@ static int do_file(void)
 
                        printf("Input file %s added\n", pci->fname);
                        pdi->nfiles++;
-                       pdi->nopenfiles++;
+                       cpu_mark_online(pdi, pci->cpu);
                }
        }
 
@@ -1613,9 +1668,9 @@ static int do_file(void)
 
                                events = read_events(pci->fd, 1);
                                if (!events) {
+                                       cpu_mark_offline(pdi, pci->cpu);
                                        close(pci->fd);
                                        pci->fd = -1;
-                                       pdi->nopenfiles--;
                                        continue;
                                }