Commit 473b7322 authored by Dev Jain's avatar Dev Jain Committed by Andrew Morton
Browse files

mm: drop all references of writable and SCAN_PAGE_RO 

Now that all actionable outcomes from checking pte_write() are gone, drop
the related references.

Link: https://lkml.kernel.org/r/20250908075028.38431-3-dev.jain@arm.com


Signed-off-by: default avatarDev Jain <dev.jain@arm.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarZi Yan <ziy@nvidia.com>
Reviewed-by: default avatarKiryl Shutsemau <kas@kernel.org>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: default avatarZach O'Keefe <zokeefe@google.com>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 62b98015

include/trace/events/huge_memory.h

+6 −13
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ 
	EM( SCAN_PTE_NON_PRESENT,	"pte_non_present")		\

	EM( SCAN_PTE_UFFD_WP,		"pte_uffd_wp")			\

	EM( SCAN_PTE_MAPPED_HUGEPAGE,	"pte_mapped_hugepage")		\

	EM( SCAN_PAGE_RO,		"no_writable_page")		\

	EM( SCAN_LACK_REFERENCED_PAGE,	"lack_referenced_page")		\

	EM( SCAN_PAGE_NULL,		"page_null")			\

	EM( SCAN_SCAN_ABORT,		"scan_aborted")			\
@@ -55,15 +54,14 @@ SCAN_STATUS 


TRACE_EVENT(mm_khugepaged_scan_pmd,



	TP_PROTO(struct mm_struct *mm, struct folio *folio, bool writable,

	TP_PROTO(struct mm_struct *mm, struct folio *folio,

		 int referenced, int none_or_zero, int status, int unmapped),



	TP_ARGS(mm, folio, writable, referenced, none_or_zero, status, unmapped),

	TP_ARGS(mm, folio, referenced, none_or_zero, status, unmapped),



	TP_STRUCT__entry(

		__field(struct mm_struct *, mm)

		__field(unsigned long, pfn)

		__field(bool, writable)

		__field(int, referenced)

		__field(int, none_or_zero)

		__field(int, status)
@@ -73,17 +71,15 @@ TRACE_EVENT(mm_khugepaged_scan_pmd, 
	TP_fast_assign(

		__entry->mm = mm;

		__entry->pfn = folio ? folio_pfn(folio) : -1;

		__entry->writable = writable;

		__entry->referenced = referenced;

		__entry->none_or_zero = none_or_zero;

		__entry->status = status;

		__entry->unmapped = unmapped;

	),



	TP_printk("mm=%p, scan_pfn=0x%lx, writable=%d, referenced=%d, none_or_zero=%d, status=%s, unmapped=%d",

	TP_printk("mm=%p, scan_pfn=0x%lx, referenced=%d, none_or_zero=%d, status=%s, unmapped=%d",

		__entry->mm,

		__entry->pfn,

		__entry->writable,

		__entry->referenced,

		__entry->none_or_zero,

		__print_symbolic(__entry->status, SCAN_STATUS),
@@ -117,15 +113,14 @@ TRACE_EVENT(mm_collapse_huge_page, 
TRACE_EVENT(mm_collapse_huge_page_isolate,



	TP_PROTO(struct folio *folio, int none_or_zero,

		 int referenced, bool  writable, int status),

		 int referenced, int status),



	TP_ARGS(folio, none_or_zero, referenced, writable, status),

	TP_ARGS(folio, none_or_zero, referenced, status),



	TP_STRUCT__entry(

		__field(unsigned long, pfn)

		__field(int, none_or_zero)

		__field(int, referenced)

		__field(bool, writable)

		__field(int, status)

	),
@@ -133,15 +128,13 @@ TRACE_EVENT(mm_collapse_huge_page_isolate, 
		__entry->pfn = folio ? folio_pfn(folio) : -1;

		__entry->none_or_zero = none_or_zero;

		__entry->referenced = referenced;

		__entry->writable = writable;

		__entry->status = status;

	),



	TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, writable=%d, status=%s",

	TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, status=%s",

		__entry->pfn,

		__entry->none_or_zero,

		__entry->referenced,

		__entry->writable,

		__print_symbolic(__entry->status, SCAN_STATUS))

);

mm/khugepaged.c

+3 −11
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ enum scan_result { 
	SCAN_PTE_NON_PRESENT,

	SCAN_PTE_UFFD_WP,

	SCAN_PTE_MAPPED_HUGEPAGE,

	SCAN_PAGE_RO,

	SCAN_LACK_REFERENCED_PAGE,

	SCAN_PAGE_NULL,

	SCAN_SCAN_ABORT,
@@ -557,7 +556,6 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, 
	struct folio *folio = NULL;

	pte_t *_pte;

	int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0;

	bool writable = false;



	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;

	     _pte++, address += PAGE_SIZE) {
@@ -671,9 +669,6 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, 
		     folio_test_referenced(folio) || mmu_notifier_test_young(vma->vm_mm,

								     address)))

			referenced++;



		if (pte_write(pteval))

			writable = true;

	}



	if (unlikely(cc->is_khugepaged && !referenced)) {
@@ -681,13 +676,13 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, 
	} else {

		result = SCAN_SUCCEED;

		trace_mm_collapse_huge_page_isolate(folio, none_or_zero,

						    referenced, writable, result);

						    referenced, result);

		return result;

	}

out:

	release_pte_pages(pte, _pte, compound_pagelist);

	trace_mm_collapse_huge_page_isolate(folio, none_or_zero,

					    referenced, writable, result);

					    referenced, result);

	return result;

}
@@ -1280,7 +1275,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, 
	unsigned long _address;

	spinlock_t *ptl;

	int node = NUMA_NO_NODE, unmapped = 0;

	bool writable = false;



	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
@@ -1344,8 +1338,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, 
			result = SCAN_PTE_UFFD_WP;

			goto out_unmap;

		}

		if (pte_write(pteval))

			writable = true;



		page = vm_normal_page(vma, _address, pteval);

		if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
@@ -1435,7 +1427,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, 
		*mmap_locked = false;

	}

out:

	trace_mm_khugepaged_scan_pmd(mm, folio, writable, referenced,

	trace_mm_khugepaged_scan_pmd(mm, folio, referenced,

				     none_or_zero, result, unmapped);

	return result;

}