[merged mm-stable] alloc_tag-expose-boot-time-compression-configuration.patch removed from -mm tree

[merged mm-stable] alloc_tag-expose-boot-time-compression-configuration.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: alloc_tag: expose boot-time compression configuration
has been removed from the -mm tree.  Its filename was
     alloc_tag-expose-boot-time-compression-configuration.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: Abhishek Bapat <abhishekbapat@google.com>
Subject: alloc_tag: expose boot-time compression configuration
Date: Wed, 5 Aug 2026 17:29:52 +0000

Currently, userspace has limited visibility into the exact active runtime
state of memory allocation profiling and its page extension compression
('sysctl.vm.mem_profiling={0|1|never}[,compressed]').

While reading the sysctl provides basic on/off status, it is currently
impossible for userspace to natively determine whether page-tag
compression was successfully enabled without scraping dmesg boot logs.

Add a new read-only sysctl representing how compression was configured
at boot time.

Link: https://lore.kernel.org/c795f8089f82841e8a6e00d7ca286da2b23aeb7b.1785950530.git.abhishekbapat@google.com
Signed-off-by: Abhishek Bapat <abhishekbapat@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Hao Ge <hao.ge@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/mm/allocation-profiling.rst |   11 +++++++++++
 mm/alloc_tag.c                            |    6 ++++++
 2 files changed, 17 insertions(+)

--- a/Documentation/mm/allocation-profiling.rst~alloc_tag-expose-boot-time-compression-configuration
+++ a/Documentation/mm/allocation-profiling.rst
@@ -43,6 +43,17 @@ sysctl:
   warnings produced by allocations made while profiling is disabled and freed
   when it's enabled.
 
+  /proc/sys/vm/mem_profiling_compressed
+
+  1: Page alloc tag compression is enabled.
+
+  0: Page alloc tag compression is disabled.
+
+  This reflects a static boot-time configuration of how page allocation tags are
+  stored (in page flags when compression is enabled and in page_ext when disabled).
+  Toggling ``mem_profiling`` at runtime does not change the state of
+  ``mem_profiling_compressed``.
+
 Runtime info:
   /proc/allocinfo
 
--- a/mm/alloc_tag.c~alloc_tag-expose-boot-time-compression-configuration
+++ a/mm/alloc_tag.c
@@ -961,6 +961,12 @@ static const struct ctl_table memory_all
 		.mode		= 0644,
 		.proc_handler	= proc_mem_profiling_handler,
 	},
+	{
+		.procname	= "mem_profiling_compressed",
+		.data		= &mem_profiling_compressed,
+		.mode		= 0444,
+		.proc_handler	= proc_do_static_key,
+	},
 };
 
 static void __init sysctl_init(void)
_

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