5.4-stable review patch. If anyone has any objections, please let me know.
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From: Carlos Galo carlosgalo@google.com
[ Upstream commit 72ba14deb40a9e9668ec5e66a341ed657e5215c2 ]
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/+/246dc8fc95b6d93a... Signed-off-by: Carlos Galo carlosgalo@google.com Reviewed-by: Steven Rostedt rostedt@goodmis.org Cc: Suren Baghdasaryan surenb@google.com Cc: Michal Hocko mhocko@suse.com Cc: "Masami Hiramatsu (Google)" mhiramat@kernel.org Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: ade81479c7dd ("memcg: fix soft lockup in the OOM process") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 26a11e4a2c361..b799f3bcba823 100644 --- a/include/trace/events/oom.h +++ b/include/trace/events/oom.h @@ -7,6 +7,8 @@ #include <linux/tracepoint.h> #include <trace/events/mmflags.h>
+#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 ee927ffeb718d..42b546c7b74b5 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -42,6 +42,7 @@ #include <linux/kthread.h> #include <linux/init.h> #include <linux/mmu_notifier.h> +#include <linux/cred.h>
#include <asm/tlb.h> #include "internal.h" @@ -721,6 +722,7 @@ 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); @@ -742,7 +744,9 @@ 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); }
/**