bcache: Better alloc tracepoints

Change the invalidate tracepoint to indicate how much data we're invalidating,
and change the alloc tracepoints to indicate what offset they're for.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

3 files changed, 46 insertions, 19 deletions

diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index c0d37d082443..a3e1427945f2 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -162,10 +162,15 @@ static bool can_invalidate_bucket(struct cache *ca, struct bucket *b)
 
 static void invalidate_one_bucket(struct cache *ca, struct bucket *b)
 {
+        size_t bucket = b - ca->buckets;
+
+        if (GC_SECTORS_USED(b))
+                trace_bcache_invalidate(ca, bucket);
+
         bch_inc_gen(ca, b);
         b->prio = INITIAL_PRIO;
         atomic_inc(&b->pin);
-        fifo_push(&ca->free_inc, b - ca->buckets);
+        fifo_push(&ca->free_inc, bucket);
 }
 
 /*
@@ -301,8 +306,6 @@ static void invalidate_buckets(struct cache *ca)
                 invalidate_buckets_random(ca);
                 break;
         }
-
-        trace_bcache_alloc_invalidate(ca);
 }
 
 #define allocator_wait(ca, cond)                                        \
@@ -408,8 +411,10 @@ long bch_bucket_alloc(struct cache *ca, unsigned reserve, bool wait)
             fifo_pop(&ca->free[reserve], r))
                 goto out;
 
-        if (!wait)
+        if (!wait) {
+                trace_bcache_alloc_fail(ca, reserve);
                 return -1;
+        }
 
         do {
                 prepare_to_wait(&ca->set->bucket_wait, &w,
@@ -425,6 +430,8 @@ long bch_bucket_alloc(struct cache *ca, unsigned reserve, bool wait)
 out:
         wake_up_process(ca->alloc_thread);
 
+        trace_bcache_alloc(ca, reserve);
+
         if (expensive_debug_checks(ca->set)) {
                 size_t iter;
                 long i;
diff --git a/drivers/md/bcache/trace.c b/drivers/md/bcache/trace.c
index adbc3df17a80..b7820b0d2621 100644
--- a/drivers/md/bcache/trace.c
+++ b/drivers/md/bcache/trace.c
@@ -45,7 +45,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_split);
 EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_compact);
 EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_set_root);
 
-EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_alloc_invalidate);
+EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_invalidate);
 EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_alloc_fail);
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writeback);
diff --git a/include/trace/events/bcache.h b/include/trace/events/bcache.h
index 7110897c3dfa..8fc2a7134d3c 100644
--- a/include/trace/events/bcache.h
+++ b/include/trace/events/bcache.h
@@ -399,26 +399,43 @@ TRACE_EVENT(bcache_keyscan,
 
 /* Allocator */
 
-TRACE_EVENT(bcache_alloc_invalidate,
-        TP_PROTO(struct cache *ca),
-        TP_ARGS(ca),
+TRACE_EVENT(bcache_invalidate,
+        TP_PROTO(struct cache *ca, size_t bucket),
+        TP_ARGS(ca, bucket),
 
         TP_STRUCT__entry(
-                __field(unsigned,       free                    )
-                __field(unsigned,       free_inc                )
-                __field(unsigned,       free_inc_size           )
-                __field(unsigned,       unused                  )
+                __field(unsigned,       sectors                 )
+                __field(dev_t,          dev                     )
+                __field(__u64,          offset                  )
         ),
 
         TP_fast_assign(
-                __entry->free           = fifo_used(&ca->free[RESERVE_NONE]);
-                __entry->free_inc       = fifo_used(&ca->free_inc);
-                __entry->free_inc_size  = ca->free_inc.size;
-                __entry->unused         = fifo_used(&ca->unused);
+                __entry->dev            = ca->bdev->bd_dev;
+                __entry->offset         = bucket << ca->set->bucket_bits;
+                __entry->sectors        = GC_SECTORS_USED(&ca->buckets[bucket]);
         ),
 
-        TP_printk("free %u free_inc %u/%u unused %u", __entry->free,
-                  __entry->free_inc, __entry->free_inc_size, __entry->unused)
+        TP_printk("invalidated %u sectors at %d,%d sector=%llu",
+                  __entry->sectors, MAJOR(__entry->dev),
+                  MINOR(__entry->dev), __entry->offset)
+);
+
+TRACE_EVENT(bcache_alloc,
+        TP_PROTO(struct cache *ca, size_t bucket),
+        TP_ARGS(ca, bucket),
+
+        TP_STRUCT__entry(
+                __field(dev_t,          dev                     )
+                __field(__u64,          offset                  )
+        ),
+
+        TP_fast_assign(
+                __entry->dev            = ca->bdev->bd_dev;
+                __entry->offset         = bucket << ca->set->bucket_bits;
+        ),
+
+        TP_printk("allocated %d,%d sector=%llu", MAJOR(__entry->dev),
+                  MINOR(__entry->dev), __entry->offset)
 );
 
 TRACE_EVENT(bcache_alloc_fail,
@@ -426,6 +443,7 @@ TRACE_EVENT(bcache_alloc_fail,
         TP_ARGS(ca, reserve),
 
         TP_STRUCT__entry(
+                __field(dev_t,          dev                     )
                 __field(unsigned,       free                    )
                 __field(unsigned,       free_inc                )
                 __field(unsigned,       unused                  )
@@ -433,13 +451,15 @@ TRACE_EVENT(bcache_alloc_fail,
         ),
 
         TP_fast_assign(
+                __entry->dev            = ca->bdev->bd_dev;
                 __entry->free           = fifo_used(&ca->free[reserve]);
                 __entry->free_inc       = fifo_used(&ca->free_inc);
                 __entry->unused         = fifo_used(&ca->unused);
                 __entry->blocked        = atomic_read(&ca->set->prio_blocked);
         ),
 
-        TP_printk("free %u free_inc %u unused %u blocked %u", __entry->free,
+        TP_printk("alloc fail %d,%d free %u free_inc %u unused %u blocked %u",
+                  MAJOR(__entry->dev), MINOR(__entry->dev), __entry->free,
                   __entry->free_inc, __entry->unused, __entry->blocked)
 );