This is a note to let you know that I've just added the patch titled
memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
memblock-free_unused_memmap-use-pageblock-units-instead-of-max_order.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Dec 15 03:01:20 PM CET 2021
From: Mark-PK Tsai <mark-pk.tsai@xxxxxxxxxxxx>
Date: Mon, 13 Dec 2021 17:41:31 +0800
Subject: memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
To: <stable@xxxxxxxxxxxxxxx>
Cc: <rppt@xxxxxxxxxx>, <akpm@xxxxxxxxxxxxxxxxxxxx>, <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <linux-mm@xxxxxxxxx>, <linux@xxxxxxxxxxxxxxx>, <rppt@xxxxxxxxxxxxx>, <tony@xxxxxxxxxxx>, <wangkefeng.wang@xxxxxxxxxx>, <mark-pk.tsai@xxxxxxxxxxxx>, <yj.chiang@xxxxxxxxxxxx>
Message-ID: <20211213094135.1798-2-mark-pk.tsai@xxxxxxxxxxxx>
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
[ Upstream commit e2a86800d58639b3acde7eaeb9eb393dca066e08 ]
The code that frees unused memory map uses rounds start and end of the
holes that are freed to MAX_ORDER_NR_PAGES to preserve continuity of the
memory map for MAX_ORDER regions.
Lots of core memory management functionality relies on homogeneity of the
memory map within each pageblock which size may differ from MAX_ORDER in
certain configurations.
Although currently, for the architectures that use free_unused_memmap(),
pageblock_order and MAX_ORDER are equivalent, it is cleaner to have common
notation thought mm code.
Replace MAX_ORDER_NR_PAGES with pageblock_nr_pages and update the comments
to make it more clear why the alignment to pageblock boundaries is
required.
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/20210630071211.21011-1-rppt@xxxxxxxxxx/
[backport upstream modification in mm/memblock.c to arch/arm/mm/init.c]
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mm/init.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -315,11 +315,11 @@ static void __init free_unused_memmap(vo
ALIGN(prev_end, PAGES_PER_SECTION));
#else
/*
- * Align down here since the VM subsystem insists that the
- * memmap entries are valid from the bank start aligned to
- * MAX_ORDER_NR_PAGES.
+ * Align down here since many operations in VM subsystem
+ * presume that there are no holes in the memory map inside
+ * a pageblock
*/
- start = round_down(start, MAX_ORDER_NR_PAGES);
+ start = round_down(start, pageblock_nr_pages);
#endif
/*
* If we had a previous bank, and there is a space
@@ -329,11 +329,11 @@ static void __init free_unused_memmap(vo
free_memmap(prev_end, start);
/*
- * Align up here since the VM subsystem insists that the
- * memmap entries are valid from the bank end aligned to
- * MAX_ORDER_NR_PAGES.
+ * Align up here since many operations in VM subsystem
+ * presume that there are no holes in the memory map inside
+ * a pageblock
*/
- prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);
+ prev_end = ALIGN(end, pageblock_nr_pages);
}
#ifdef CONFIG_SPARSEMEM
Patches currently in stable-queue which might be from mark-pk.tsai@xxxxxxxxxxxx are
queue-5.10/arm-extend-pfn_valid-to-take-into-account-freed-memory-map-alignment.patch
queue-5.10/arm-ioremap-don-t-abuse-pfn_valid-to-check-if-pfn-is-in-ram.patch
queue-5.10/memblock-free_unused_memmap-use-pageblock-units-instead-of-max_order.patch
queue-5.10/memblock-align-freed-memory-map-on-pageblock-boundaries-with-sparsemem.patch
queue-5.10/memblock-ensure-there-is-no-overflow-in-memblock_overlaps_region.patch
