+ mm-zsmalloc-convert-reset_page-to-reset_zpdesc.patch added to mm-unstable branch

+ mm-zsmalloc-convert-reset_page-to-reset_zpdesc.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/zsmalloc: convert reset_page to reset_zpdesc
has been added to the -mm mm-unstable branch.  Its filename is
     mm-zsmalloc-convert-reset_page-to-reset_zpdesc.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zsmalloc-convert-reset_page-to-reset_zpdesc.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Alex Shi <alexs@kernel.org>
Subject: mm/zsmalloc: convert reset_page to reset_zpdesc
Date: Tue, 17 Dec 2024 00:04:42 +0900

zpdesc.zspage matches with page.private, zpdesc.next matches with
page.index.  They will be reset in reset_page() which is called prior to
free base pages of a zspage.

Since the fields that need to be initialized are independent of the order
in struct zpdesc, Keep it to use struct page to ensure robustness against
potential rearrangements of struct zpdesc fields in the future.

[42.hyeyoo@gmail.com: keep reset_zpdesc() to use struct page fields]
Link: https://lkml.kernel.org/r/20241216150450.1228021-12-42.hyeyoo@gmail.com
Signed-off-by: Alex Shi <alexs@kernel.org>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zsmalloc.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/mm/zsmalloc.c~mm-zsmalloc-convert-reset_page-to-reset_zpdesc
+++ a/mm/zsmalloc.c
@@ -843,8 +843,10 @@ static inline bool obj_allocated(struct
 	return true;
 }
 
-static void reset_page(struct page *page)
+static void reset_zpdesc(struct zpdesc *zpdesc)
 {
+	struct page *page = zpdesc_page(zpdesc);
+
 	__ClearPageMovable(page);
 	ClearPagePrivate(page);
 	set_page_private(page, 0);
@@ -887,7 +889,7 @@ static void __free_zspage(struct zs_pool
 	do {
 		VM_BUG_ON_PAGE(!PageLocked(page), page);
 		next = get_next_page(page);
-		reset_page(page);
+		reset_zpdesc(page_zpdesc(page));
 		unlock_page(page);
 		dec_zone_page_state(page, NR_ZSPAGES);
 		put_page(page);
@@ -1865,7 +1867,7 @@ static int zs_page_migrate(struct page *
 		zpdesc_inc_zone_page_state(newzpdesc);
 	}
 
-	reset_page(page);
+	reset_zpdesc(zpdesc);
 	zpdesc_put(zpdesc);
 
 	return MIGRATEPAGE_SUCCESS;
_

Patches currently in -mm which might be from alexs@kernel.org are

mm-zsmalloc-add-zpdesc-memory-descriptor-for-zswapzpool.patch
mm-zsmalloc-use-zpdesc-in-trylock_zspage-lock_zspage.patch
mm-zsmalloc-convert-create_page_chain-and-its-users-to-use-zpdesc.patch
mm-zsmalloc-convert-reset_page-to-reset_zpdesc.patch
mm-zsmalloc-convert-setzspagemovable-and-remove-unused-funcs.patch
mm-zsmalloc-convert-get-set_first_obj_offset-to-take-zpdesc.patch
mm-zsmalloc-introduce-__zpdesc_clear-set_zsmalloc.patch