[merged mm-stable] mm-update-mark_victim-tracepoints-fields.patch removed from -mm tree

[merged mm-stable] mm-update-mark_victim-tracepoints-fields.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: update mark_victim tracepoints fields
has been removed from the -mm tree.  Its filename was
     mm-update-mark_victim-tracepoints-fields.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Carlos Galo <carlosgalo@google.com>
Subject: mm: update mark_victim tracepoints fields
Date: Thu, 11 Jan 2024 21:05:30 +0000

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 that need additional information about the OOM victim.
The association between pid and the additional data may be lost after the
kill, making it difficult for userspace to correlate the OOM event with
the specific process.

In order to mitigate this limitation, add the following fields:

- 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
   Allows userspace to get additional insights of the relative kill
   priority of the OOM victim.

Link: https://lkml.kernel.org/r/20240111210539.636607-1-carlosgalo@google.com
Signed-off-by: Carlos Galo <carlosgalo@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/trace/events/oom.h |   19 +++++++++++++++----
 mm/oom_kill.c              |    6 +++++-
 2 files changed, 20 insertions(+), 5 deletions(-)

--- a/include/trace/events/oom.h~mm-update-mark_victim-tracepoints-fields
+++ a/include/trace/events/oom.h
@@ -72,19 +72,30 @@ 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)
+		__field(uid_t, uid)
+		__string(comm, task->comm)
+		__field(short, oom_score_adj)
 	),
 
 	TP_fast_assign(
-		__entry->pid = pid;
+		__entry->pid = task->pid;
+		__entry->uid = uid;
+		__assign_str(comm, task->comm);
+		__entry->oom_score_adj = task->signal->oom_score_adj;
 	),
 
-	TP_printk("pid=%d", __entry->pid)
+	TP_printk("pid=%d uid=%u comm=%s oom_score_adj=%hd",
+		__entry->pid,
+		__entry->uid,
+		__get_str(comm),
+		__entry->oom_score_adj
+	)
 );
 
 TRACE_EVENT(wake_reaper,
--- a/mm/oom_kill.c~mm-update-mark_victim-tracepoints-fields
+++ a/mm/oom_kill.c
@@ -44,6 +44,7 @@
 #include <linux/kthread.h>
 #include <linux/init.h>
 #include <linux/mmu_notifier.h>
+#include <linux/cred.h>
 
 #include <asm/tlb.h>
 #include "internal.h"
@@ -754,6 +755,7 @@ static inline void queue_oom_reaper(stru
  */
 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_
 	 */
 	__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);
 }
 
 /**
_

Patches currently in -mm which might be from carlosgalo@google.com are

[merged mm-stable] mm-update-mark_victim-tracepoints-fields.patch removed from -mm tree

[Andrew Morton]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 4968 bytes --]


The quilt patch titled
     Subject: mm: update mark_victim tracepoints fields
has been removed from the -mm tree.  Its filename was
     mm-update-mark_victim-tracepoints-fields.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Carlos Galo <carlosgalo@google.com>
Subject: mm: update mark_victim tracepoints fields
Date: Fri, 23 Feb 2024 17:32:49 +0000

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 <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>
---

 include/trace/events/oom.h |   36 +++++++++++++++++++++++++++++++----
 mm/oom_kill.c              |    6 ++++-
 2 files changed, 37 insertions(+), 5 deletions(-)

--- a/include/trace/events/oom.h~mm-update-mark_victim-tracepoints-fields
+++ a/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,
--- a/mm/oom_kill.c~mm-update-mark_victim-tracepoints-fields
+++ a/mm/oom_kill.c
@@ -44,6 +44,7 @@
 #include <linux/kthread.h>
 #include <linux/init.h>
 #include <linux/mmu_notifier.h>
+#include <linux/cred.h>
 
 #include <asm/tlb.h>
 #include "internal.h"
@@ -754,6 +755,7 @@ static inline void queue_oom_reaper(stru
  */
 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_
 	 */
 	__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);
 }
 
 /**
_

Patches currently in -mm which might be from carlosgalo@google.com are