implement umfPoolTrimMemory

Author: bratpiorka

include/umf/memory_pool.h

@@ -196,6 +196,24 @@ umf_result_t umfPoolSetTag(umf_memory_pool_handle_t hPool, void *tag,
 /// @return UMF_RESULT_SUCCESS on success.
 umf_result_t umfPoolGetTag(umf_memory_pool_handle_t hPool, void **tag);
 
+///
+/// @brief Trims memory of the pool, removing resources that are not needed
+///        to keep the pool operational.
+/// \details
+///        The minBytesToKeep parameter is a hint to the pool implementation
+///        that it should try to keep at least this number of bytes of
+///        memory in the pool. The pool implementation may also ignore this
+///        parameter and not trim memory at all, in which case it should
+///        return UMF_RESULT_SUCCESS. The pool implementation may also return
+///        UMF_RESULT_ERROR_NOT_SUPPORTED if it does not support trimming
+///        memory.
+/// @param pool pointer to the memory pool
+/// @param minBytesToKeep minimum number of bytes to keep in the pool (if
+///        possible - see details)
+/// @return UMF_RESULT_SUCCESS on success or appropriate error code on failure.
+umf_result_t umfPoolTrimMemory(umf_memory_pool_handle_t hPool,
+                               size_t minBytesToKeep);
+
 #ifdef __cplusplus
 }
 #endif

include/umf/memory_pool_ops.h

@@ -22,7 +22,7 @@ extern "C" {
 /// @brief Version of the Memory Pool ops structure.
 /// NOTE: This is equal to the latest UMF version, in which the ops structure
 /// has been modified.
-#define UMF_POOL_OPS_VERSION_CURRENT UMF_MAKE_VERSION(1, 0)
+#define UMF_POOL_OPS_VERSION_CURRENT UMF_MAKE_VERSION(1, 1)
 
 ///
 /// @brief This structure comprises function pointers used by corresponding umfPool*
@@ -166,6 +166,26 @@ typedef struct umf_memory_pool_ops_t {
                             const char *name, void *arg, size_t size,
                             umf_ctl_query_type_t queryType, va_list args);
 
+    // The following operations were added in ops version 1.1
+
+    ///
+    /// @brief Trims memory of the pool, removing resources that are not needed
+    ///        to keep the pool operational.
+    /// \details
+    ///        The minBytesToKeep parameter is a hint to the pool implementation
+    ///        that it should try to keep at least this number of bytes of
+    ///        memory in the pool. The pool implementation may also ignore this
+    ///        parameter and not trim memory at all, in which case it should
+    ///        return UMF_RESULT_SUCCESS. The pool implementation may also return
+    ///        UMF_RESULT_ERROR_NOT_SUPPORTED if it does not support trimming
+    ///        memory.
+    /// @param pool pointer to the memory pool
+    /// @param minBytesToKeep minimum number of bytes to keep in the pool (if
+    ///        possible - see details)
+    /// @return UMF_RESULT_SUCCESS on success or appropriate error code on
+    ///         failure.
+    ///
+    umf_result_t (*ext_trim_memory)(void *pool, size_t minBytesToKeep);
 } umf_memory_pool_ops_t;
 
 #ifdef __cplusplus

src/libumf.def

@@ -152,4 +152,5 @@ EXPORTS
     umfJemallocPoolParamsSetName
     umfLevelZeroMemoryProviderParamsSetName
     umfOsMemoryProviderParamsSetName
+    umfPoolTrimMemory
     umfScalablePoolParamsSetName

src/libumf.map

@@ -150,5 +150,6 @@ UMF_1.1 {
     umfJemallocPoolParamsSetName;
     umfLevelZeroMemoryProviderParamsSetName;
     umfOsMemoryProviderParamsSetName;
+    umfPoolTrimMemory;
     umfScalablePoolParamsSetName;
 } UMF_1.0;

src/memory_pool.c

@@ -212,6 +212,13 @@ umfDefaultCtlPoolHandle(void *hPool, umf_ctl_query_source_t operationType,
     return UMF_RESULT_ERROR_NOT_SUPPORTED;
 }
 
+static umf_result_t umfDefaultTrimMemory(void *provider,
+                                         size_t minBytesToKeep) {
+    (void)provider;
+    (void)minBytesToKeep;
+    return UMF_RESULT_ERROR_NOT_SUPPORTED;
+}
+
 // logical sum (OR) of all umf_pool_create_flags_t flags
 static const umf_pool_create_flags_t UMF_POOL_CREATE_FLAG_ALL =
     UMF_POOL_CREATE_FLAG_OWN_PROVIDER | UMF_POOL_CREATE_FLAG_DISABLE_TRACKING;
@@ -233,9 +240,9 @@ static umf_result_t umfPoolCreateInternal(const umf_memory_pool_ops_t *ops,
                                           const void *params,
                                           umf_pool_create_flags_t flags,
                                           umf_memory_pool_handle_t *hPool) {
-    if (!ops || !provider || !hPool) {
-        return UMF_RESULT_ERROR_INVALID_ARGUMENT;
-    }
+    UMF_CHECK((ops != NULL), UMF_RESULT_ERROR_INVALID_ARGUMENT);
+    UMF_CHECK((provider != NULL), UMF_RESULT_ERROR_INVALID_ARGUMENT);
+    UMF_CHECK((hPool != NULL), UMF_RESULT_ERROR_INVALID_ARGUMENT);
 
     // validate flags
     if (flags & ~UMF_POOL_CREATE_FLAG_ALL) {
@@ -245,10 +252,26 @@ static umf_result_t umfPoolCreateInternal(const umf_memory_pool_ops_t *ops,
 
     umf_result_t ret = UMF_RESULT_SUCCESS;
 
+    umf_memory_pool_ops_t compatible_ops;
     if (ops->version != UMF_POOL_OPS_VERSION_CURRENT) {
         LOG_WARN("Memory Pool ops version \"%d\" is different than the current "
                  "version \"%d\"",
                  ops->version, UMF_POOL_OPS_VERSION_CURRENT);
+
+        // Create a new ops compatible structure with the current version
+        memset(&compatible_ops, 0, sizeof(compatible_ops));
+        if (UMF_MINOR_VERSION(ops->version) == 0) {
+            LOG_INFO("Detected 1.0 version of Memory Pool ops, "
+                     "upgrading to current version");
+            memcpy(&compatible_ops, ops,
+                   offsetof(umf_memory_pool_ops_t, ext_trim_memory));
+        } else {
+            LOG_ERR("Memory Pool ops unknown version, which \"%d\" is not "
+                    "supported",
+                    ops->version);
+            return UMF_RESULT_ERROR_NOT_SUPPORTED;
+        }
+        ops = &compatible_ops;
     }
 
     umf_memory_pool_handle_t pool =
@@ -278,6 +301,10 @@ static umf_result_t umfPoolCreateInternal(const umf_memory_pool_ops_t *ops,
         pool->ops.ext_ctl = umfDefaultCtlPoolHandle;
     }
 
+    if (NULL == pool->ops.ext_trim_memory) {
+        pool->ops.ext_trim_memory = umfDefaultTrimMemory;
+    }
+
     if (NULL == utils_mutex_init(&pool->lock)) {
         LOG_ERR("Failed to initialize mutex for pool");
         ret = UMF_RESULT_ERROR_UNKNOWN;
@@ -326,10 +353,7 @@ static umf_result_t umfPoolCreateInternal(const umf_memory_pool_ops_t *ops,
 }
 
 umf_result_t umfPoolDestroy(umf_memory_pool_handle_t hPool) {
-    if (hPool == NULL) {
-        LOG_ERR("memory pool handle is NULL");
-        return UMF_RESULT_ERROR_INVALID_ARGUMENT;
-    }
+    UMF_CHECK((hPool != NULL), UMF_RESULT_ERROR_INVALID_ARGUMENT);
 
     if (umf_ba_global_is_destroyed()) {
         return UMF_RESULT_ERROR_UNKNOWN;
@@ -509,6 +533,13 @@ umf_result_t umfPoolGetTag(umf_memory_pool_handle_t hPool, void **tag) {
     return UMF_RESULT_SUCCESS;
 }
 
+umf_result_t umfPoolTrimMemory(umf_memory_pool_handle_t hPool,
+                               size_t minBytesToKeep) {
+    UMF_CHECK((hPool != NULL), UMF_RESULT_ERROR_INVALID_ARGUMENT);
+
+    return hPool->ops.ext_trim_memory(hPool->pool_priv, minBytesToKeep);
+}
+
 void umfPoolCtlDefaultsDestroy(void) {
     utils_init_once(&mem_pool_ctl_initialized, pool_ctl_init);
 

src/pool/pool_disjoint.c

@@ -444,11 +444,11 @@ static void bucket_free_chunk(bucket_t *bucket, void *ptr, slab_t *slab,
             // remove slab
             slab_list_item_t *slab_it = &slab->iter;
             assert(slab_it->val != NULL);
-            pool_unregister_slab(bucket->pool, slab_it->val);
+            destroy_slab(slab_it->val);
             DL_DELETE(bucket->available_slabs, slab_it);
             assert(bucket->available_slabs_num > 0);
             bucket->available_slabs_num--;
-            destroy_slab(slab_it->val);
+            pool_unregister_slab(bucket->pool, slab_it->val);
         }
     } else {
         // return this chunk to the pool
@@ -1133,6 +1133,43 @@ static umf_result_t disjoint_pool_get_name(void *pool, const char **name) {
     return UMF_RESULT_SUCCESS;
 }
 
+umf_result_t disjoint_pool_trim_memory(void *pool, size_t minBytesToKeep) {
+    assert(pool != NULL);
+    disjoint_pool_t *hPool = (disjoint_pool_t *)pool;
+
+    for (size_t i = 0; i < hPool->buckets_num; i++) {
+        bucket_t *bucket = hPool->buckets[i];
+        utils_mutex_lock(&bucket->bucket_lock);
+
+        // remove empty slabs from the pool
+        slab_list_item_t *it = NULL, *tmp = NULL;
+        LL_FOREACH_SAFE(bucket->available_slabs, it, tmp) {
+            slab_t *slab = it->val;
+            if (slab->num_chunks_allocated == 0) {
+                if (minBytesToKeep >= slab->slab_size) {
+                    // if we still have bytes to keep, do not remove slab
+                    minBytesToKeep -= slab->slab_size;
+                    continue;
+                }
+
+                // remove slab
+                destroy_slab(slab);
+                DL_DELETE(bucket->available_slabs, it);
+                assert(bucket->available_slabs_num > 0);
+                bucket->available_slabs_num--;
+                pool_unregister_slab(hPool, slab);
+
+                // update stats
+                bucket_update_stats(bucket, 0, -1);
+            }
+        }
+
+        utils_mutex_unlock(&bucket->bucket_lock);
+    }
+
+    return UMF_RESULT_SUCCESS;
+}
+
 static umf_memory_pool_ops_t UMF_DISJOINT_POOL_OPS = {
     .version = UMF_POOL_OPS_VERSION_CURRENT,
     .initialize = disjoint_pool_initialize,
@@ -1146,6 +1183,7 @@ static umf_memory_pool_ops_t UMF_DISJOINT_POOL_OPS = {
     .get_last_allocation_error = disjoint_pool_get_last_allocation_error,
     .get_name = disjoint_pool_get_name,
     .ext_ctl = disjoint_pool_ctl,
+    .ext_trim_memory = disjoint_pool_trim_memory,
 };
 
 const umf_memory_pool_ops_t *umfDisjointPoolOps(void) {

src/pool/pool_jemalloc.c

@@ -588,6 +588,28 @@ static umf_result_t op_get_name(void *pool, const char **name) {
     return UMF_RESULT_SUCCESS;
 }
 
+static umf_result_t op_trim_memory(void *pool, size_t minBytesToKeep) {
+    // there is no way to tell jemalloc to keep a minimum number of bytes
+    // so we just purge all arenas
+    if (minBytesToKeep > 0) {
+        LOG_WARN("Ignoring minBytesToKeep (%zu) in jemalloc pool",
+                 minBytesToKeep);
+    }
+
+    jemalloc_memory_pool_t *je_pool = (jemalloc_memory_pool_t *)pool;
+    for (size_t i = 0; i < je_pool->n_arenas; i++) {
+        char cmd[64];
+        unsigned arena = je_pool->arena_index[i];
+        snprintf(cmd, sizeof(cmd), "arena.%u.purge", arena);
+        if (je_mallctl(cmd, NULL, NULL, NULL, 0)) {
+            LOG_ERR("Could not purge jemalloc arena %u", arena);
+            return UMF_RESULT_ERROR_UNKNOWN;
+        }
+    }
+
+    return UMF_RESULT_SUCCESS;
+}
+
 static umf_memory_pool_ops_t UMF_JEMALLOC_POOL_OPS = {
     .version = UMF_POOL_OPS_VERSION_CURRENT,
     .initialize = op_initialize,
@@ -600,6 +622,7 @@ static umf_memory_pool_ops_t UMF_JEMALLOC_POOL_OPS = {
     .free = op_free,
     .get_last_allocation_error = op_get_last_allocation_error,
     .get_name = op_get_name,
+    .ext_trim_memory = op_trim_memory,
 };
 
 const umf_memory_pool_ops_t *umfJemallocPoolOps(void) {

src/pool/pool_proxy.c

@@ -147,7 +147,9 @@ static umf_memory_pool_ops_t UMF_PROXY_POOL_OPS = {
     .malloc_usable_size = proxy_malloc_usable_size,
     .free = proxy_free,
     .get_last_allocation_error = proxy_get_last_allocation_error,
-    .get_name = proxy_get_name};
+    .get_name = proxy_get_name,
+    .ext_trim_memory = NULL, // not supported
+};
 
 const umf_memory_pool_ops_t *umfProxyPoolOps(void) {
     return &UMF_PROXY_POOL_OPS;

src/pool/pool_scalable.c

@@ -450,12 +450,14 @@ static umf_result_t tbb_get_last_allocation_error(void *pool) {
     return TLS_last_allocation_error;
 }
 
+static void initialize_pool_ctl(void) {}
+
 static umf_result_t pool_ctl(void *hPool, umf_ctl_query_source_t operationType,
                              const char *name, void *arg, size_t size,
                              umf_ctl_query_type_t query_type, va_list args) {
     (void)operationType; // unused
     umf_memory_pool_handle_t pool_provider = (umf_memory_pool_handle_t)hPool;
-    utils_init_once(&ctl_initialized, NULL);
+    utils_init_once(&ctl_initialized, initialize_pool_ctl);
     return ctl_query(&pool_scallable_ctl_root, pool_provider->pool_priv,
                      CTL_QUERY_PROGRAMMATIC, name, query_type, arg, size, args);
 }
@@ -486,6 +488,7 @@ static umf_memory_pool_ops_t UMF_SCALABLE_POOL_OPS = {
     .get_last_allocation_error = tbb_get_last_allocation_error,
     .ext_ctl = pool_ctl,
     .get_name = scalable_get_name,
+    .ext_trim_memory = NULL, // not supported
 };
 
 const umf_memory_pool_ops_t *umfScalablePoolOps(void) {

src/utils/utils_posix_concurrency.c

@@ -38,6 +38,11 @@ int utils_mutex_unlock(utils_mutex_t *m) {
 }
 
 void utils_init_once(UTIL_ONCE_FLAG *flag, void (*oneCb)(void)) {
+    if (oneCb == NULL) {
+        LOG_FATAL("utils_init_once: callback is NULL");
+        return;
+    }
+
     pthread_once(flag, oneCb);
 }