mem-pool: add tracking of mem_pool that requested the allocation

This renames the current 'struct mem_pool' to 'struct mem_pool_shared'.
The mem_pool_shared is globally allocated and not specific for
particular objects.

A new 'struct mem_pool' gets allocated when mem_pool_new() is called. It
points to the mem_pool_shared that handles the actual allocation
requests. The 'struct mem_pool' is only used for accounting of the
objects that the caller requested and free'd.

All of these changes will be used to collect all the memory pools a
glusterfs_ctx_t is consuming, so that statedumps can be collected per
context.

Updates: #307
Change-Id: I6355d3f0251c928e0bbfc71be3431307c6f3a3da
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: https://review.gluster.org/18073
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>

1 files changed, 17 insertions, 3 deletions

diff --git a/libglusterfs/src/mem-pool.h b/libglusterfs/src/mem-pool.h
index 1272ad4d5fc..cc7df0b77c8 100644
--- a/libglusterfs/src/mem-pool.h
+++ b/libglusterfs/src/mem-pool.h
@@ -203,18 +203,31 @@ out:
         return dup_mem;
 }
 
+/* kind of 'header' for the actual mem_pool_shared structure, this might make
+ * it possible to dump some more details in a statedump */
+struct mem_pool {
+        unsigned long           sizeof_type;
+        unsigned long           count;
+        char                    *name;
+
+        struct mem_pool_shared  *pool;
+};
+
 typedef struct pooled_obj_hdr {
         unsigned long                   magic;
         struct pooled_obj_hdr           *next;
         struct per_thread_pool_list     *pool_list;
         unsigned int                    power_of_two;
+
+        /* track the pool that was used to request this object */
+        struct mem_pool                 *pool;
 } pooled_obj_hdr_t;
 
 #define AVAILABLE_SIZE(p2)      ((1 << (p2)) - sizeof(pooled_obj_hdr_t))
 
 typedef struct per_thread_pool {
-        /* This never changes, so doesn't need a lock. */
-        struct mem_pool         *parent;
+        /* the pool that was used to request this allocation */
+        struct mem_pool_shared  *parent;
         /* Everything else is protected by our own lock. */
         pooled_obj_hdr_t        *hot_list;
         pooled_obj_hdr_t        *cold_list;
@@ -242,7 +255,8 @@ typedef struct per_thread_pool_list {
         per_thread_pool_t       pools[1];
 } per_thread_pool_list_t;
 
-struct mem_pool {
+/* actual pool structure, shared between different mem_pools */
+struct mem_pool_shared {
         unsigned int            power_of_two;
         /*
          * Updates to these are *not* protected by a global lock, so races