[merged mm-stable] perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker.patch removed from -mm tree

[merged mm-stable] perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: perf/ring_buffer: stop using PG_private as AUX page high-order marker
has been removed from the -mm tree.  Its filename was
     perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker.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: Zi Yan <ziy@nvidia.com>
Subject: perf/ring_buffer: stop using PG_private as AUX page high-order marker
Date: Sun, 20 Sep 2026 22:27:58 -0400

A high-order AUX page sets PG_private on its first page and stores the
order in first_page->private.  Stop using PG_private and check
first_page->private for AUX page order only in the ring buffer and its
users.  This is fine because page->private is 0 for order-0 AUX pages,
matching the page order.

It prepares for a future commit that remove PG_private.

No functional change intended.

Link: https://lore.kernel.org/20260920-remove-pg_private-v5-2-bb68b6a21869@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---

 arch/x86/events/intel/bts.c |    3 ---
 arch/x86/events/intel/pt.c  |    6 ++----
 kernel/events/ring_buffer.c |    7 +++----
 3 files changed, 5 insertions(+), 11 deletions(-)

--- a/arch/x86/events/intel/bts.c~perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker
+++ a/arch/x86/events/intel/bts.c
@@ -66,9 +66,6 @@ static struct pmu bts_pmu;
 
 static int buf_nr_pages(struct page *page)
 {
-	if (!PagePrivate(page))
-		return 1;
-
 	return 1 << page_private(page);
 }
 
--- a/arch/x86/events/intel/pt.c~perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker
+++ a/arch/x86/events/intel/pt.c
@@ -781,8 +781,7 @@ static int topa_insert_pages(struct pt_b
 	struct page *p;
 
 	p = virt_to_page(buf->data_pages[buf->nr_pages]);
-	if (PagePrivate(p))
-		order = page_private(p);
+	order = page_private(p);
 
 	if (topa_table_full(topa)) {
 		topa = topa_alloc(cpu, gfp);
@@ -1296,8 +1295,7 @@ static int pt_buffer_try_single(struct p
 	if (!intel_pt_validate_hw_cap(PT_CAP_single_range_output))
 		goto out;
 
-	if (PagePrivate(p))
-		order = page_private(p);
+	order = page_private(p);
 
 	if (1 << order != nr_pages)
 		goto out;
--- a/kernel/events/ring_buffer.c~perf-ring_buffer-stop-using-pg_private-as-aux-page-high-order-marker
+++ a/kernel/events/ring_buffer.c
@@ -635,11 +635,10 @@ static struct page *rb_alloc_aux_page(in
 		/*
 		 * Communicate the allocation size to the driver:
 		 * if we managed to secure a high-order allocation,
-		 * set its first page's private to this order;
-		 * !PagePrivate(page) means it's just a normal page.
+		 * set its first page's private to this order, otherwise page's
+		 * private remains zero.
 		 */
 		split_page(page, order);
-		SetPagePrivate(page);
 		set_page_private(page, order);
 	}
 
@@ -650,7 +649,7 @@ static void rb_free_aux_page(struct perf
 {
 	struct page *page = virt_to_page(rb->aux_pages[idx]);
 
-	ClearPagePrivate(page);
+	set_page_private(page, 0);
 	__free_page(page);
 }
 
_

Patches currently in -mm which might be from ziy@nvidia.com are