On Thu, Feb 15, 2024 at 08:47:59AM -0800, Suren Baghdasaryan wrote:

On Thu, Feb 15, 2024 at 8:45 AM Michal Hocko [off-list ref] wrote:

quoted

On Thu 15-02-24 06:58:42, Suren Baghdasaryan wrote:

quoted

On Thu, Feb 15, 2024 at 1:22 AM Michal Hocko [off-list ref] wrote:

quoted

On Mon 12-02-24 13:39:17, Suren Baghdasaryan wrote:
[...]

quoted

@@ -423,4 +424,18 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
 #ifdef CONFIG_MEMORY_FAILURE
      printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages));
 #endif
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+     {
+             struct seq_buf s;
+             char *buf = kmalloc(4096, GFP_ATOMIC);
+
+             if (buf) {
+                     printk("Memory allocations:\n");
+                     seq_buf_init(&s, buf, 4096);
+                     alloc_tags_show_mem_report(&s);
+                     printk("%s", buf);
+                     kfree(buf);
+             }
+     }
+#endif

I am pretty sure I have already objected to this. Memory allocations in
the oom path are simply no go unless there is absolutely no other way
around that. In this case the buffer could be preallocated.

Good point. We will change this to a smaller buffer allocated on the
stack and will print records one-by-one. Thanks!

__show_mem could be called with a very deep call chains. A single
pre-allocated buffer should just do ok.

Ack. Will do.

No, we're not going to permanently burn 4k here.

It's completely fine if the allocation fails, there's nothing "unsafe"
about doing a GFP_ATOMIC allocation here.