From 72ba14deb40a9e9668ec5e66a341ed657e5215c2 Mon Sep 17 00:00:00 2001 From: Carlos Galo Date: Fri, 23 Feb 2024 17:32:49 +0000 Subject: [PATCH] mm: update mark_victim tracepoints fields MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current implementation of the mark_victim tracepoint provides only the process ID (pid) of the victim process. This limitation poses challenges for userspace tools requiring real-time OOM analysis and intervention. Although this information is available from the kernel logs, it’s not the appropriate format to provide OOM notifications. In Android, BPF programs are used with the mark_victim trace events to notify userspace of an OOM kill. For consistency, update the trace event to include the same information about the OOMed victim as the kernel logs. - UID In Android each installed application has a unique UID. Including the `uid` assists in correlating OOM events with specific apps. - Process Name (comm) Enables identification of the affected process. - OOM Score Will allow userspace to get additional insight of the relative kill priority of the OOM victim. In Android, the oom_score_adj is used to categorize app state (foreground, background, etc.), which aids in analyzing user-perceptible impacts of OOM events [1]. - Total VM, RSS Stats, and pgtables Amount of memory used by the victim that will, potentially, be freed up by killing it. [1] https://cs.android.com/android/platform/superproject/main/+/246dc8fc95b6d93afcba5c6d6c133307abb3ac2e:frameworks/base/services/core/java/com/android/server/am/ProcessList.java;l=188-283 Signed-off-by: Carlos Galo Reviewed-by: Steven Rostedt Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Signed-off-by: Andrew Morton --- include/trace/events/oom.h | 36 ++++++++++++++++++++++++++++++++---- mm/oom_kill.c | 6 +++++- 2 files changed, 37 insertions(+), 5 deletions(-) diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h index 26a11e4a2c36..b799f3bcba82 100644 --- a/include/trace/events/oom.h +++ b/include/trace/events/oom.h @@ -7,6 +7,8 @@ #include #include +#define PG_COUNT_TO_KB(x) ((x) << (PAGE_SHIFT - 10)) + TRACE_EVENT(oom_score_adj_update, TP_PROTO(struct task_struct *task), @@ -72,19 +74,45 @@ TRACE_EVENT(reclaim_retry_zone, ); TRACE_EVENT(mark_victim, - TP_PROTO(int pid), + TP_PROTO(struct task_struct *task, uid_t uid), - TP_ARGS(pid), + TP_ARGS(task, uid), TP_STRUCT__entry( __field(int, pid) + __string(comm, task->comm) + __field(unsigned long, total_vm) + __field(unsigned long, anon_rss) + __field(unsigned long, file_rss) + __field(unsigned long, shmem_rss) + __field(uid_t, uid) + __field(unsigned long, pgtables) + __field(short, oom_score_adj) ), TP_fast_assign( - __entry->pid = pid; + __entry->pid = task->pid; + __assign_str(comm, task->comm); + __entry->total_vm = PG_COUNT_TO_KB(task->mm->total_vm); + __entry->anon_rss = PG_COUNT_TO_KB(get_mm_counter(task->mm, MM_ANONPAGES)); + __entry->file_rss = PG_COUNT_TO_KB(get_mm_counter(task->mm, MM_FILEPAGES)); + __entry->shmem_rss = PG_COUNT_TO_KB(get_mm_counter(task->mm, MM_SHMEMPAGES)); + __entry->uid = uid; + __entry->pgtables = mm_pgtables_bytes(task->mm) >> 10; + __entry->oom_score_adj = task->signal->oom_score_adj; ), - TP_printk("pid=%d", __entry->pid) + TP_printk("pid=%d comm=%s total-vm=%lukB anon-rss=%lukB file-rss:%lukB shmem-rss:%lukB uid=%u pgtables=%lukB oom_score_adj=%hd", + __entry->pid, + __get_str(comm), + __entry->total_vm, + __entry->anon_rss, + __entry->file_rss, + __entry->shmem_rss, + __entry->uid, + __entry->pgtables, + __entry->oom_score_adj + ) ); TRACE_EVENT(wake_reaper, diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 91ccd82097c2..8d6a207c3c59 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -44,6 +44,7 @@ #include #include #include +#include #include #include "internal.h" @@ -754,6 +755,7 @@ static inline void queue_oom_reaper(struct task_struct *tsk) */ static void mark_oom_victim(struct task_struct *tsk) { + const struct cred *cred; struct mm_struct *mm = tsk->mm; WARN_ON(oom_killer_disabled); @@ -773,7 +775,9 @@ static void mark_oom_victim(struct task_struct *tsk) */ __thaw_task(tsk); atomic_inc(&oom_victims); - trace_mark_victim(tsk->pid); + cred = get_task_cred(tsk); + trace_mark_victim(tsk, cred->uid.val); + put_cred(cred); } /**