From 940e7cf8bd9162310d6c621d3caa77ec407f80ef Mon Sep 17 00:00:00 2001
From: Suren Baghdasaryan <surenb@google.com>
Date: Thu, 27 May 2021 18:15:44 -0700
Subject: [PATCH] lmkd: Include total GPU memory usage in killinfo reports

/sys/fs/bpf/map_gpu_mem_gpu_mem_total_map BPF map exposes total GPU
allocations size. Include this value into killinfo reports to track GPU
allocation size at the time of the kill.

Bug: 189366037
Test: lmkd_unit_test
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: Icc1ed8ab2593530fa293ff9c82f6c8dc400485f5
---
 Android.bp    |  3 +++
 event.logtags |  2 +-
 lmkd.cpp      | 21 +++++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/Android.bp b/Android.bp
index fcf26ca..4f53ded 100644
--- a/Android.bp
+++ b/Android.bp
@@ -23,6 +23,9 @@ cc_binary {
         "libstatslogc",
         "liblmkd_utils",
     ],
+    header_libs: [
+        "bpf_syscall_wrappers",
+    ],
     local_include_dirs: ["include"],
     cflags: [
         "-Wall",
diff --git a/event.logtags b/event.logtags
index 0de32b7..5382b49 100644
--- a/event.logtags
+++ b/event.logtags
@@ -35,4 +35,4 @@
 # TODO: generate ".java" and ".h" files with integer constants from this file.
 
 # for killinfo logs
-10195355 killinfo (Pid|1|5),(Uid|1|5),(OomAdj|1),(MinOomAdj|1),(TaskSize|1),(enum kill_reasons|1|5),(MemFree|1),(Cached|1),(SwapCached|1),(Buffers|1),(Shmem|1),(Unevictable|1),(SwapTotal|1),(SwapFree|1),(ActiveAnon|1),(InactiveAnon|1),(ActiveFile|1),(InactiveFile|1),(SReclaimable|1),(SUnreclaim|1),(KernelStack|1),(PageTables|1),(IonHeap|1),(IonHeapPool|1),(CmaFree|1),(MsSinceEvent|1),(MsSincePrevWakeup|1),(WakeupsSinceEvent|1),(SkippedWakeups|1),(TaskSwapSize|1)
+10195355 killinfo (Pid|1|5),(Uid|1|5),(OomAdj|1),(MinOomAdj|1),(TaskSize|1),(enum kill_reasons|1|5),(MemFree|1),(Cached|1),(SwapCached|1),(Buffers|1),(Shmem|1),(Unevictable|1),(SwapTotal|1),(SwapFree|1),(ActiveAnon|1),(InactiveAnon|1),(ActiveFile|1),(InactiveFile|1),(SReclaimable|1),(SUnreclaim|1),(KernelStack|1),(PageTables|1),(IonHeap|1),(IonHeapPool|1),(CmaFree|1),(MsSinceEvent|1),(MsSincePrevWakeup|1),(WakeupsSinceEvent|1),(SkippedWakeups|1),(TaskSwapSize|1),(GPU|1)
diff --git a/lmkd.cpp b/lmkd.cpp
index dc93ac4..0afcf2f 100644
--- a/lmkd.cpp
+++ b/lmkd.cpp
@@ -53,6 +53,9 @@
 
 #include "statslog.h"
 
+#define BPF_FD_JUST_USE_INT
+#include "BpfSyscallWrappers.h"
+
 /*
  * Define LMKD_TRACE_KILLS to record lmkd kills in kernel traces
  * to profile and correlate with OOM kills
@@ -431,6 +434,7 @@ union meminfo {
         int64_t cma_free;
         /* fields below are calculated rather than read from the file */
         int64_t nr_file_pages;
+        int64_t total_gpu_kb;
     } field;
     int64_t arr[MI_FIELD_COUNT];
 };
@@ -1785,6 +1789,21 @@ static bool meminfo_parse_line(char *line, union meminfo *mi) {
     return (match_res != PARSE_FAIL);
 }
 
+static int64_t read_gpu_total_kb() {
+    static int fd = android::bpf::bpfFdGet(
+            "/sys/fs/bpf/map_gpu_mem_gpu_mem_total_map", BPF_F_RDONLY);
+    static constexpr uint64_t kBpfKeyGpuTotalUsage = 0;
+    uint64_t value;
+
+    if (fd < 0) {
+        return 0;
+    }
+
+    return android::bpf::findMapEntry(fd, &kBpfKeyGpuTotalUsage, &value)
+            ? 0
+            : (int32_t)(value / 1024);
+}
+
 static int meminfo_parse(union meminfo *mi) {
     static struct reread_data file_data = {
         .filename = MEMINFO_PATH,
@@ -1809,6 +1828,7 @@ static int meminfo_parse(union meminfo *mi) {
     }
     mi->field.nr_file_pages = mi->field.cached + mi->field.swap_cached +
         mi->field.buffers;
+    mi->field.total_gpu_kb = read_gpu_total_kb();
 
     return 0;
 }
@@ -1923,6 +1943,7 @@ static void killinfo_log(struct proc* procp, int min_oom_score, int rss_kb,
     android_log_write_int32(ctx, wi->wakeups_since_event);
     android_log_write_int32(ctx, wi->skipped_wakeups);
     android_log_write_int32(ctx, (int32_t)min(swap_kb, INT32_MAX));
+    android_log_write_int32(ctx, (int32_t)mi->field.total_gpu_kb);
 
     android_log_write_list(ctx, LOG_ID_EVENTS);
     android_log_reset(ctx);