6.9-stable patches

added patches:
	mm-page_alloc-separate-thp-pcp-into-movable-and-non-movable-categories.patch

diff --git a/queue-6.9/mm-page_alloc-separate-thp-pcp-into-movable-and-non-movable-categories.patch b/queue-6.9/mm-page_alloc-separate-thp-pcp-into-movable-and-non-movable-categories.patch
new file mode 100644 (file)
index 0000000..06131bb
--- /dev/null
+++ b/queue-6.9/mm-page_alloc-separate-thp-pcp-into-movable-and-non-movable-categories.patch
@@ -0,0 +1,109 @@
+From bf14ed81f571f8dba31cd72ab2e50fbcc877cc31 Mon Sep 17 00:00:00 2001
+From: yangge <yangge1116@126.com>
+Date: Thu, 20 Jun 2024 08:59:50 +0800
+Subject: mm/page_alloc: Separate THP PCP into movable and non-movable categories
+
+From: yangge <yangge1116@126.com>
+
+commit bf14ed81f571f8dba31cd72ab2e50fbcc877cc31 upstream.
+
+Since commit 5d0a661d808f ("mm/page_alloc: use only one PCP list for
+THP-sized allocations") no longer differentiates the migration type of
+pages in THP-sized PCP list, it's possible that non-movable allocation
+requests may get a CMA page from the list, in some cases, it's not
+acceptable.
+
+If a large number of CMA memory are configured in system (for example, the
+CMA memory accounts for 50% of the system memory), starting a virtual
+machine with device passthrough will get stuck.  During starting the
+virtual machine, it will call pin_user_pages_remote(..., FOLL_LONGTERM,
+...) to pin memory.  Normally if a page is present and in CMA area,
+pin_user_pages_remote() will migrate the page from CMA area to non-CMA
+area because of FOLL_LONGTERM flag.  But if non-movable allocation
+requests return CMA memory, migrate_longterm_unpinnable_pages() will
+migrate a CMA page to another CMA page, which will fail to pass the check
+in check_and_migrate_movable_pages() and cause migration endless.
+
+Call trace:
+pin_user_pages_remote
+--__gup_longterm_locked // endless loops in this function
+----_get_user_pages_locked
+----check_and_migrate_movable_pages
+------migrate_longterm_unpinnable_pages
+--------alloc_migration_target
+
+This problem will also have a negative impact on CMA itself.  For example,
+when CMA is borrowed by THP, and we need to reclaim it through cma_alloc()
+or dma_alloc_coherent(), we must move those pages out to ensure CMA's
+users can retrieve that contigous memory.  Currently, CMA's memory is
+occupied by non-movable pages, meaning we can't relocate them.  As a
+result, cma_alloc() is more likely to fail.
+
+To fix the problem above, we add one PCP list for THP, which will not
+introduce a new cacheline for struct per_cpu_pages.  THP will have 2 PCP
+lists, one PCP list is used by MOVABLE allocation, and the other PCP list
+is used by UNMOVABLE allocation.  MOVABLE allocation contains GPF_MOVABLE,
+and UNMOVABLE allocation contains GFP_UNMOVABLE and GFP_RECLAIMABLE.
+
+Link: https://lkml.kernel.org/r/1718845190-4456-1-git-send-email-yangge1116@126.com
+Fixes: 5d0a661d808f ("mm/page_alloc: use only one PCP list for THP-sized allocations")
+Signed-off-by: yangge <yangge1116@126.com>
+Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
+Cc: Barry Song <21cnbao@gmail.com>
+Cc: Mel Gorman <mgorman@techsingularity.net>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/linux/mmzone.h |    9 ++++-----
+ mm/page_alloc.c        |    9 +++++++--
+ 2 files changed, 11 insertions(+), 7 deletions(-)
+
+--- a/include/linux/mmzone.h
++++ b/include/linux/mmzone.h
+@@ -651,13 +651,12 @@ enum zone_watermarks {
+ };
+ 
+ /*
+- * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
+- * for THP which will usually be GFP_MOVABLE. Even if it is another type,
+- * it should not contribute to serious fragmentation causing THP allocation
+- * failures.
++ * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. Two additional lists
++ * are added for THP. One PCP list is used by GPF_MOVABLE, and the other PCP list
++ * is used by GFP_UNMOVABLE and GFP_RECLAIMABLE.
+  */
+ #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+-#define NR_PCP_THP 1
++#define NR_PCP_THP 2
+ #else
+ #define NR_PCP_THP 0
+ #endif
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -521,10 +521,15 @@ out:
+ 
+ static inline unsigned int order_to_pindex(int migratetype, int order)
+ {
++      bool __maybe_unused movable;
++
+ #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       if (order > PAGE_ALLOC_COSTLY_ORDER) {
+               VM_BUG_ON(order != pageblock_order);
+-              return NR_LOWORDER_PCP_LISTS;
++
++              movable = migratetype == MIGRATE_MOVABLE;
++
++              return NR_LOWORDER_PCP_LISTS + movable;
+       }
+ #else
+       VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
+@@ -538,7 +543,7 @@ static inline int pindex_to_order(unsign
+       int order = pindex / MIGRATE_PCPTYPES;
+ 
+ #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+-      if (pindex == NR_LOWORDER_PCP_LISTS)
++      if (pindex >= NR_LOWORDER_PCP_LISTS)
+               order = pageblock_order;
+ #else
+       VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);

diff --git a/queue-6.9/series b/queue-6.9/series
index 35ccbcba8c9ff21f86ae7f82005a37edbd99a1d9..b96f2c62beee4cd7e78ee4751367c35b09e32b2c 100644 (file)
--- a/queue-6.9/series
+++ b/queue-6.9/series
@@ -199,3 +199,4 @@ bcachefs-fix-bch2_sb_downgrade_update.patch
 bcachefs-fix-setting-of-downgrade-recovery-passes-errors.patch
 bcachefs-btree_gc-can-now-handle-unknown-btrees.patch
 revert-net-sfp-enhance-quirk-for-fibrestore-2.5g-copper-sfp-module.patch
+mm-page_alloc-separate-thp-pcp-into-movable-and-non-movable-categories.patch