diff --git a/ggml/src/ggml-vulkan/ggml-vulkan.cpp b/ggml/src/ggml-vulkan/ggml-vulkan.cpp
index 0a79310..7905c84 100644
--- a/ggml/src/ggml-vulkan/ggml-vulkan.cpp
+++ b/ggml/src/ggml-vulkan/ggml-vulkan.cpp
@@ -2612,8 +2612,14 @@ static void ggml_vk_command_pool_cleanup(vk_device& device, vk_command_pool& p)
 static void ggml_vk_queue_command_pools_cleanup(vk_device& device) {
     VK_LOG_DEBUG("ggml_vk_queue_command_pools_cleanup()");
 
-    // Arbitrary frequency to cleanup/reuse command buffers
-    static constexpr uint32_t cleanup_frequency = 10;
+    // Arbitrary frequency to cleanup/reuse command buffers.
+    // rocky-vulkan-llama: env-tunable. panvk's small (~4GB) priv VA heap OOMs when many
+    // cmdbufs (each retaining a large per-cmdbuf TLS/WLS BO) accumulate before reset;
+    // GGML_VK_CMD_CLEANUP_FREQ lowers the accumulation bound on Mali/panvk.
+    static const uint32_t cleanup_frequency = []() {
+        const char *e = getenv("GGML_VK_CMD_CLEANUP_FREQ");
+        return e ? (uint32_t)atoi(e) : 10u;
+    }();
 
     if (device->compute_queue.cmd_pool.buffers_in_use() >= cleanup_frequency) {
         ggml_vk_command_pool_cleanup(device, device->compute_queue.cmd_pool);
@@ -14684,11 +14690,14 @@ static ggml_status ggml_backend_vk_graph_compute(ggml_backend_t backend, ggml_cg
     // (and scaled down based on model size, so smaller models submit earlier).
     // Also submit at least every 100 nodes, in case there are workloads without as much matmul.
     int nodes_per_submit = 100;
+    if (const char* e = getenv("GGML_VK_NODES_PER_SUBMIT")) { nodes_per_submit = atoi(e); }
     int submitted_nodes = 0;
     int submit_count = 0;
     uint64_t mul_mat_bytes = 0;
     uint64_t total_mul_mat_bytes = 0;
-    uint64_t mul_mat_bytes_per_submit = std::min(uint64_t(100*1000*1000), ctx->last_total_mul_mat_bytes / 40u);
+    uint64_t mul_mat_bytes_cap = 100*1000*1000;
+    if (const char* e = getenv("GGML_VK_MAX_MUL_MAT_BYTES_PER_SUBMIT")) { mul_mat_bytes_cap = strtoull(e, nullptr, 10); }
+    uint64_t mul_mat_bytes_per_submit = std::min(mul_mat_bytes_cap, ctx->last_total_mul_mat_bytes / 40u);
     for (int i = 0; i < cgraph->n_nodes; i++) {
         if (first_node_in_batch) {
             submit_node_idx = i;
@@ -14925,7 +14934,7 @@ static ggml_status ggml_backend_vk_graph_compute(ggml_backend_t backend, ggml_cg
             submitted_nodes = 0;
             mul_mat_bytes = 0;
             if (submit_count < 3) {
-                mul_mat_bytes_per_submit *= 2;
+                mul_mat_bytes_per_submit = std::min(mul_mat_bytes_per_submit * 2, mul_mat_bytes_cap);
             }
             submit_count++;
         }