--- zzzz-none-000/linux-5.4.213/drivers/block/zram/zram_drv.c	2022-09-15 10:04:56.000000000 +0000
+++ miami-7690-761/linux-5.4.213/drivers/block/zram/zram_drv.c	2024-05-29 11:19:50.000000000 +0000
@@ -33,6 +33,8 @@
 #include <linux/sysfs.h>
 #include <linux/debugfs.h>
 #include <linux/cpuhotplug.h>
+#include <avm/sammel/debug.h>
+#include <avm/enh/semi_seq.h>
 
 #include "zram_drv.h"
 
@@ -1873,6 +1875,44 @@
 	NULL,
 };
 
+static int oom_info_callback(struct notifier_block *block, unsigned long event, void *_data)
+{
+	struct zram *zram = container_of(block, struct zram, oom_info_block);
+	struct seq_file *file = _data;
+	struct zs_pool_stats pool_stats;
+	u64 orig_size, mem_used = 0;
+	long max_used;
+
+	memset(&pool_stats, 0x00, sizeof(struct zs_pool_stats));
+
+	// Unlik mm_stat we don't use semaphores to lock the access here. This is needed as the
+	// info_callback is called in an atomic context.
+	//
+	// All of the calls made here are either normal reads or atomic reads. Which can be done
+	// unguarded. The worst is, that we get inconsistent data, which should be easily detectable
+	// by inspecting the output.
+	if (init_done(zram)) {
+		mem_used = zs_get_total_pages(zram->mem_pool);
+		zs_pool_stats(zram->mem_pool, &pool_stats);
+	}
+
+	orig_size = atomic64_read(&zram->stats.pages_stored);
+	max_used = atomic_long_read(&zram->stats.max_used_pages);
+
+	sseq_printf(file,
+			"%s: orig:%lluKiB compr:%lluKiB used:%lluKiB limit:%luKiB max:%ldKiB same:%llu compact:%lu\n",
+			zram->disk->disk_name,
+			orig_size << (PAGE_SHIFT - 10),
+			(u64)atomic64_read(&zram->stats.compr_data_size) >> 10,
+			mem_used << (PAGE_SHIFT - 10),
+			zram->limit_pages << (PAGE_SHIFT - 10),
+			max_used << (PAGE_SHIFT - 10),
+			(u64)atomic64_read(&zram->stats.same_pages),
+			atomic_long_read(&pool_stats.pages_compacted));
+
+	return NOTIFY_DONE;
+}
+
 /*
  * Allocate and initialize new zram device. the function returns
  * '>= 0' device_id upon success, and negative value otherwise.
@@ -1960,6 +2000,9 @@
 	strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));
 
 	zram_debugfs_register(zram);
+	zram->oom_info_block.notifier_call = oom_info_callback;
+	avm_oom_info_chain_register(&zram->oom_info_block);
+
 	pr_info("Added device: %s\n", zram->disk->disk_name);
 	return device_id;
 
@@ -1990,6 +2033,8 @@
 	zram->claim = true;
 	mutex_unlock(&bdev->bd_mutex);
 
+	avm_oom_info_chain_unregister(&zram->oom_info_block);
+
 	zram_debugfs_unregister(zram);
 
 	/* Make sure all the pending I/O are finished */