GPU Memory: add bpf c program for gpu_mem/gpu_mem_total tracepoint
This change implements the bpf map and program to be attached to
gpu_mem/gpu_mem_total tracepoint. Access groups of both the map and the
program are setup properly for gpuservice.
Bug: 154524735
Test: After requiring gpu_mem.o, the below should exist
1. /system/etc/bpf/gpu_mem.o
2. /sys/fs/bpf/map_gpu_mem_gpu_mem_total_map
3. /sys/fs/bpf/prog_gpu_mem_tracepoint_gpu_mem_gpu_mem_total
Change-Id: Ic09cdfbbbd5de82920cba7b96045891b81a2ecf1
diff --git a/services/gpuservice/bpfprogs/Android.bp b/services/gpuservice/bpfprogs/Android.bp
new file mode 100644
index 0000000..b875814
--- /dev/null
+++ b/services/gpuservice/bpfprogs/Android.bp
@@ -0,0 +1,22 @@
+// Copyright 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+bpf {
+ name: "gpu_mem.o",
+ srcs: ["gpu_mem.c"],
+ cflags: [
+ "-Wall",
+ "-Werror",
+ ],
+}
diff --git a/services/gpuservice/bpfprogs/gpu_mem.c b/services/gpuservice/bpfprogs/gpu_mem.c
new file mode 100644
index 0000000..c75213b
--- /dev/null
+++ b/services/gpuservice/bpfprogs/gpu_mem.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <bpf_helpers.h>
+
+/*
+ * On Android the number of active processes using gpu is limited.
+ * So this is assumed to be true: SUM(num_procs_using_gpu[i]) <= 1024
+ */
+#define GPU_MEM_TOTAL_MAP_SIZE 1024
+
+/*
+ * This map maintains the global and per process gpu memory total counters.
+ *
+ * The KEY is ((gpu_id << 32) | pid) while VAL is the size in bytes.
+ * Use HASH type here since key is not int.
+ * Pass AID_GRAPHICS as gid since gpuservice is in the graphics group.
+ */
+DEFINE_BPF_MAP_GRO(gpu_mem_total_map, HASH, uint64_t, uint64_t, GPU_MEM_TOTAL_MAP_SIZE,
+ AID_GRAPHICS);
+
+/* This struct aligns with the fields offsets of the raw tracepoint format */
+struct gpu_mem_total_args {
+ uint64_t ignore;
+ /* Actual fields start at offset 8 */
+ uint32_t gpu_id;
+ uint32_t pid;
+ uint64_t size;
+};
+
+/*
+ * This program parses the gpu_mem/gpu_mem_total tracepoint's data into
+ * {KEY, VAL} pair used to update the corresponding bpf map.
+ *
+ * Pass AID_GRAPHICS as gid since gpuservice is in the graphics group.
+ * Upon seeing size 0, the corresponding KEY needs to be cleaned up.
+ */
+DEFINE_BPF_PROG("tracepoint/gpu_mem/gpu_mem_total", AID_ROOT, AID_GRAPHICS, tp_gpu_mem_total)
+(struct gpu_mem_total_args* args) {
+ uint64_t key = 0;
+ uint64_t cur_val = 0;
+ uint64_t* prev_val = NULL;
+
+ /* The upper 32 bits are for gpu_id while the lower is the pid */
+ key = ((uint64_t)args->gpu_id << 32) | args->pid;
+ cur_val = args->size;
+
+ if (!cur_val) {
+ bpf_gpu_mem_total_map_delete_elem(&key);
+ return 0;
+ }
+
+ prev_val = bpf_gpu_mem_total_map_lookup_elem(&key);
+ if (prev_val) {
+ *prev_val = cur_val;
+ } else {
+ bpf_gpu_mem_total_map_update_elem(&key, &cur_val, BPF_NOEXIST);
+ }
+ return 0;
+}
+
+char _license[] SEC("license") = "Apache 2.0";