The patch titled
Subject: mm: hugetlb_vmemmap: delete hugetlb_optimize_vmemmap_enabled()
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb_vmemmap-delete-hugetlb_optimize_vmemmap_enabled.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb_vmemmap-delete-hugetlb_optimize_vmemmap_enabled.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: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: hugetlb_vmemmap: delete hugetlb_optimize_vmemmap_enabled()
Date: Tue, 28 Jun 2022 17:22:28 +0800
Patch series "Simplify hugetlb vmemmap and improve its readability", v2.
This series aims to simplify hugetlb vmemmap and improve its readability.
This patch (of 8):
The name hugetlb_optimize_vmemmap_enabled() a bit confusing as it tests
two conditions (enabled and pages in use). Instead of coming up to an
appropriate name, we could just delete it. There is already a discussion
about deleting it in thread [1].
There is only one user of hugetlb_optimize_vmemmap_enabled() outside of
hugetlb_vmemmap, that is flush_dcache_page() in arch/arm64/mm/flush.c.
However, it does not need to call hugetlb_optimize_vmemmap_enabled() in
flush_dcache_page() since HugeTLB pages are always fully mapped and only
head page will be set PG_dcache_clean meaning only head page's flag may
need to be cleared (see commit cf5a501d985b). So it is easy to remove
hugetlb_optimize_vmemmap_enabled().
Link: https://lore.kernel.org/all/c77c61c8-8a5a-87e8-db89-d04d8aaab4cc@xxxxxxxxxx/ [1]
Link: https://lkml.kernel.org/r/20220628092235.91270-2-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/mm/flush.c | 13 +++----------
include/linux/page-flags.h | 14 ++------------
2 files changed, 5 insertions(+), 22 deletions(-)
--- a/arch/arm64/mm/flush.c~mm-hugetlb_vmemmap-delete-hugetlb_optimize_vmemmap_enabled
+++ a/arch/arm64/mm/flush.c
@@ -76,17 +76,10 @@ EXPORT_SYMBOL_GPL(__sync_icache_dcache);
void flush_dcache_page(struct page *page)
{
/*
- * Only the head page's flags of HugeTLB can be cleared since the tail
- * vmemmap pages associated with each HugeTLB page are mapped with
- * read-only when CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is enabled (more
- * details can refer to vmemmap_remap_pte()). Although
- * __sync_icache_dcache() only set PG_dcache_clean flag on the head
- * page struct, there is more than one page struct with PG_dcache_clean
- * associated with the HugeTLB page since the head vmemmap page frame
- * is reused (more details can refer to the comments above
- * page_fixed_fake_head()).
+ * HugeTLB pages are always fully mapped and only head page will be
+ * set PG_dcache_clean (see comments in __sync_icache_dcache()).
*/
- if (hugetlb_optimize_vmemmap_enabled() && PageHuge(page))
+ if (PageHuge(page))
page = compound_head(page);
if (test_bit(PG_dcache_clean, &page->flags))
--- a/include/linux/page-flags.h~mm-hugetlb_vmemmap-delete-hugetlb_optimize_vmemmap_enabled
+++ a/include/linux/page-flags.h
@@ -208,12 +208,6 @@ enum pageflags {
DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
hugetlb_optimize_vmemmap_key);
-static __always_inline bool hugetlb_optimize_vmemmap_enabled(void)
-{
- return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
- &hugetlb_optimize_vmemmap_key);
-}
-
/*
* If the feature of optimizing vmemmap pages associated with each HugeTLB
* page is enabled, the head vmemmap page frame is reused and all of the tail
@@ -232,7 +226,8 @@ static __always_inline bool hugetlb_opti
*/
static __always_inline const struct page *page_fixed_fake_head(const struct page *page)
{
- if (!hugetlb_optimize_vmemmap_enabled())
+ if (!static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
+ &hugetlb_optimize_vmemmap_key))
return page;
/*
@@ -260,11 +255,6 @@ static inline const struct page *page_fi
{
return page;
}
-
-static inline bool hugetlb_optimize_vmemmap_enabled(void)
-{
- return false;
-}
#endif
static __always_inline int page_is_fake_head(struct page *page)
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-sparsemem-fix-missing-higher-order-allocation-splitting.patch
mm-memory_hotplug-enumerate-all-supported-section-flags.patch
mm-memory_hotplug-enumerate-all-supported-section-flags-v5.patch
mm-memory_hotplug-make-hugetlb_optimize_vmemmap-compatible-with-memmap_on_memory.patch
mm-memory_hotplug-make-hugetlb_optimize_vmemmap-compatible-with-memmap_on_memory-v5.patch
mm-hugetlb-remove-minimum_order-variable.patch
mm-memcontrol-remove-dead-code-and-comments.patch
mm-rename-unlock_page_lruvec_irq-_irqrestore-to-lruvec_unlock_irq-_irqrestore.patch
mm-memcontrol-prepare-objcg-api-for-non-kmem-usage.patch
mm-memcontrol-make-lruvec-lock-safe-when-lru-pages-are-reparented.patch
mm-vmscan-rework-move_pages_to_lru.patch
mm-thp-make-split-queue-lock-safe-when-lru-pages-are-reparented.patch
mm-memcontrol-make-all-the-callers-of-foliopage_memcg-safe.patch
mm-memcontrol-introduce-memcg_reparent_ops.patch
mm-memcontrol-use-obj_cgroup-apis-to-charge-the-lru-pages.patch
mm-lru-add-vm_warn_on_once_folio-to-lru-maintenance-function.patch
mm-hugetlb_vmemmap-delete-hugetlb_optimize_vmemmap_enabled.patch
mm-hugetlb_vmemmap-optimize-vmemmap_optimize_mode-handling.patch
mm-hugetlb_vmemmap-introduce-the-name-hvo.patch
mm-hugetlb_vmemmap-move-vmemmap-code-related-to-hugetlb-to-hugetlb_vmemmapc.patch
mm-hugetlb_vmemmap-replace-early_param-with-core_param.patch
mm-hugetlb_vmemmap-improve-hugetlb_vmemmap-code-readability.patch
mm-hugetlb_vmemmap-move-code-comments-to-vmemmap_deduprst.patch
mm-hugetlb_vmemmap-use-ptrs_per_pte-instead-of-pmd_size-page_size.patch
