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authorLinus Torvalds <torvalds@linux-foundation.org>2023-11-02 19:38:47 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2023-11-02 19:38:47 -1000
commitecae0bd5173b1014f95a14a8dfbe40ec10367dcf (patch)
treef571213ef1a35354ea79f0240a180fdb4111b290 /mm/rmap.c
parentbc3012f4e3a9765de81f454cb8f9bb16aafc6ff5 (diff)
parent9732336006764e2ee61225387e3c70eae9139035 (diff)
downloadlwn-ecae0bd5173b1014f95a14a8dfbe40ec10367dcf.tar.gz
lwn-ecae0bd5173b1014f95a14a8dfbe40ec10367dcf.zip
Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Kemeng Shi has contributed some compation maintenance work in the series 'Fixes and cleanups to compaction' - Joel Fernandes has a patchset ('Optimize mremap during mutual alignment within PMD') which fixes an obscure issue with mremap()'s pagetable handling during a subsequent exec(), based upon an implementation which Linus suggested - More DAMON/DAMOS maintenance and feature work from SeongJae Park i the following patch series: mm/damon: misc fixups for documents, comments and its tracepoint mm/damon: add a tracepoint for damos apply target regions mm/damon: provide pseudo-moving sum based access rate mm/damon: implement DAMOS apply intervals mm/damon/core-test: Fix memory leaks in core-test mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval - In the series 'Do not try to access unaccepted memory' Adrian Hunter provides some fixups for the recently-added 'unaccepted memory' feature. To increase the feature's checking coverage. 'Plug a few gaps where RAM is exposed without checking if it is unaccepted memory' - In the series 'cleanups for lockless slab shrink' Qi Zheng has done some maintenance work which is preparation for the lockless slab shrinking code - Qi Zheng has redone the earlier (and reverted) attempt to make slab shrinking lockless in the series 'use refcount+RCU method to implement lockless slab shrink' - David Hildenbrand contributes some maintenance work for the rmap code in the series 'Anon rmap cleanups' - Kefeng Wang does more folio conversions and some maintenance work in the migration code. Series 'mm: migrate: more folio conversion and unification' - Matthew Wilcox has fixed an issue in the buffer_head code which was causing long stalls under some heavy memory/IO loads. Some cleanups were added on the way. Series 'Add and use bdev_getblk()' - In the series 'Use nth_page() in place of direct struct page manipulation' Zi Yan has fixed a potential issue with the direct manipulation of hugetlb page frames - In the series 'mm: hugetlb: Skip initialization of gigantic tail struct pages if freed by HVO' has improved our handling of gigantic pages in the hugetlb vmmemmep optimizaton code. This provides significant boot time improvements when significant amounts of gigantic pages are in use - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code rationalization and folio conversions in the hugetlb code - Yin Fengwei has improved mlock()'s handling of large folios in the series 'support large folio for mlock' - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has added statistics for memcg v1 users which are available (and useful) under memcg v2 - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable) prctl so that userspace may direct the kernel to not automatically propagate the denial to child processes. The series is named 'MDWE without inheritance' - Kefeng Wang has provided the series 'mm: convert numa balancing functions to use a folio' which does what it says - In the series 'mm/ksm: add fork-exec support for prctl' Stefan Roesch makes is possible for a process to propagate KSM treatment across exec() - Huang Ying has enhanced memory tiering's calculation of memory distances. This is used to permit the dax/kmem driver to use 'high bandwidth memory' in addition to Optane Data Center Persistent Memory Modules (DCPMM). The series is named 'memory tiering: calculate abstract distance based on ACPI HMAT' - In the series 'Smart scanning mode for KSM' Stefan Roesch has optimized KSM by teaching it to retain and use some historical information from previous scans - Yosry Ahmed has fixed some inconsistencies in memcg statistics in the series 'mm: memcg: fix tracking of pending stats updates values' - In the series 'Implement IOCTL to get and optionally clear info about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap which permits us to atomically read-then-clear page softdirty state. This is mainly used by CRIU - Hugh Dickins contributed the series 'shmem,tmpfs: general maintenance', a bunch of relatively minor maintenance tweaks to this code - Matthew Wilcox has increased the use of the VMA lock over file-backed page faults in the series 'Handle more faults under the VMA lock'. Some rationalizations of the fault path became possible as a result - In the series 'mm/rmap: convert page_move_anon_rmap() to folio_move_anon_rmap()' David Hildenbrand has implemented some cleanups and folio conversions - In the series 'various improvements to the GUP interface' Lorenzo Stoakes has simplified and improved the GUP interface with an eye to providing groundwork for future improvements - Andrey Konovalov has sent along the series 'kasan: assorted fixes and improvements' which does those things - Some page allocator maintenance work from Kemeng Shi in the series 'Two minor cleanups to break_down_buddy_pages' - In thes series 'New selftest for mm' Breno Leitao has developed another MM self test which tickles a race we had between madvise() and page faults - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups and an optimization to the core pagecache code - Nhat Pham has added memcg accounting for hugetlb memory in the series 'hugetlb memcg accounting' - Cleanups and rationalizations to the pagemap code from Lorenzo Stoakes, in the series 'Abstract vma_merge() and split_vma()' - Audra Mitchell has fixed issues in the procfs page_owner code's new timestamping feature which was causing some misbehaviours. In the series 'Fix page_owner's use of free timestamps' - Lorenzo Stoakes has fixed the handling of new mappings of sealed files in the series 'permit write-sealed memfd read-only shared mappings' - Mike Kravetz has optimized the hugetlb vmemmap optimization in the series 'Batch hugetlb vmemmap modification operations' - Some buffer_head folio conversions and cleanups from Matthew Wilcox in the series 'Finish the create_empty_buffers() transition' - As a page allocator performance optimization Huang Ying has added automatic tuning to the allocator's per-cpu-pages feature, in the series 'mm: PCP high auto-tuning' - Roman Gushchin has contributed the patchset 'mm: improve performance of accounted kernel memory allocations' which improves their performance by ~30% as measured by a micro-benchmark - folio conversions from Kefeng Wang in the series 'mm: convert page cpupid functions to folios' - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about kmemleak' - Qi Zheng has improved our handling of memoryless nodes by keeping them off the allocation fallback list. This is done in the series 'handle memoryless nodes more appropriately' - khugepaged conversions from Vishal Moola in the series 'Some khugepaged folio conversions'" [ bcachefs conflicts with the dynamically allocated shrinkers have been resolved as per Stephen Rothwell in https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/ with help from Qi Zheng. The clone3 test filtering conflict was half-arsed by yours truly ] * tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits) mm/damon/sysfs: update monitoring target regions for online input commit mm/damon/sysfs: remove requested targets when online-commit inputs selftests: add a sanity check for zswap Documentation: maple_tree: fix word spelling error mm/vmalloc: fix the unchecked dereference warning in vread_iter() zswap: export compression failure stats Documentation: ubsan: drop "the" from article title mempolicy: migration attempt to match interleave nodes mempolicy: mmap_lock is not needed while migrating folios mempolicy: alloc_pages_mpol() for NUMA policy without vma mm: add page_rmappable_folio() wrapper mempolicy: remove confusing MPOL_MF_LAZY dead code mempolicy: mpol_shared_policy_init() without pseudo-vma mempolicy trivia: use pgoff_t in shared mempolicy tree mempolicy trivia: slightly more consistent naming mempolicy trivia: delete those ancient pr_debug()s mempolicy: fix migrate_pages(2) syscall return nr_failed kernfs: drop shared NUMA mempolicy hooks hugetlbfs: drop shared NUMA mempolicy pretence mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets() ...
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c164
1 files changed, 101 insertions, 63 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 9f795b93cf40..7a27a2b41802 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -798,6 +798,7 @@ struct folio_referenced_arg {
unsigned long vm_flags;
struct mem_cgroup *memcg;
};
+
/*
* arg: folio_referenced_arg will be passed
*/
@@ -807,17 +808,33 @@ static bool folio_referenced_one(struct folio *folio,
struct folio_referenced_arg *pra = arg;
DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, 0);
int referenced = 0;
+ unsigned long start = address, ptes = 0;
while (page_vma_mapped_walk(&pvmw)) {
address = pvmw.address;
- if ((vma->vm_flags & VM_LOCKED) &&
- (!folio_test_large(folio) || !pvmw.pte)) {
- /* Restore the mlock which got missed */
- mlock_vma_folio(folio, vma, !pvmw.pte);
- page_vma_mapped_walk_done(&pvmw);
- pra->vm_flags |= VM_LOCKED;
- return false; /* To break the loop */
+ if (vma->vm_flags & VM_LOCKED) {
+ if (!folio_test_large(folio) || !pvmw.pte) {
+ /* Restore the mlock which got missed */
+ mlock_vma_folio(folio, vma);
+ page_vma_mapped_walk_done(&pvmw);
+ pra->vm_flags |= VM_LOCKED;
+ return false; /* To break the loop */
+ }
+ /*
+ * For large folio fully mapped to VMA, will
+ * be handled after the pvmw loop.
+ *
+ * For large folio cross VMA boundaries, it's
+ * expected to be picked by page reclaim. But
+ * should skip reference of pages which are in
+ * the range of VM_LOCKED vma. As page reclaim
+ * should just count the reference of pages out
+ * the range of VM_LOCKED vma.
+ */
+ ptes++;
+ pra->mapcount--;
+ continue;
}
if (pvmw.pte) {
@@ -842,6 +859,23 @@ static bool folio_referenced_one(struct folio *folio,
pra->mapcount--;
}
+ if ((vma->vm_flags & VM_LOCKED) &&
+ folio_test_large(folio) &&
+ folio_within_vma(folio, vma)) {
+ unsigned long s_align, e_align;
+
+ s_align = ALIGN_DOWN(start, PMD_SIZE);
+ e_align = ALIGN_DOWN(start + folio_size(folio) - 1, PMD_SIZE);
+
+ /* folio doesn't cross page table boundary and fully mapped */
+ if ((s_align == e_align) && (ptes == folio_nr_pages(folio))) {
+ /* Restore the mlock which got missed */
+ mlock_vma_folio(folio, vma);
+ pra->vm_flags |= VM_LOCKED;
+ return false; /* To break the loop */
+ }
+ }
+
if (referenced)
folio_clear_idle(folio);
if (folio_test_clear_young(folio))
@@ -1094,19 +1128,17 @@ int folio_total_mapcount(struct folio *folio)
}
/**
- * page_move_anon_rmap - move a page to our anon_vma
- * @page: the page to move to our anon_vma
- * @vma: the vma the page belongs to
+ * folio_move_anon_rmap - move a folio to our anon_vma
+ * @folio: The folio to move to our anon_vma
+ * @vma: The vma the folio belongs to
*
- * When a page belongs exclusively to one process after a COW event,
- * that page can be moved into the anon_vma that belongs to just that
- * process, so the rmap code will not search the parent or sibling
- * processes.
+ * When a folio belongs exclusively to one process after a COW event,
+ * that folio can be moved into the anon_vma that belongs to just that
+ * process, so the rmap code will not search the parent or sibling processes.
*/
-void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
+void folio_move_anon_rmap(struct folio *folio, struct vm_area_struct *vma)
{
void *anon_vma = vma->anon_vma;
- struct folio *folio = page_folio(page);
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
VM_BUG_ON_VMA(!anon_vma, vma);
@@ -1118,31 +1150,25 @@ void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
* folio_test_anon()) will not see one without the other.
*/
WRITE_ONCE(folio->mapping, anon_vma);
- SetPageAnonExclusive(page);
}
/**
- * __page_set_anon_rmap - set up new anonymous rmap
- * @folio: Folio which contains page.
- * @page: Page to add to rmap.
- * @vma: VM area to add page to.
+ * __folio_set_anon - set up a new anonymous rmap for a folio
+ * @folio: The folio to set up the new anonymous rmap for.
+ * @vma: VM area to add the folio to.
* @address: User virtual address of the mapping
- * @exclusive: the page is exclusively owned by the current process
+ * @exclusive: Whether the folio is exclusive to the process.
*/
-static void __page_set_anon_rmap(struct folio *folio, struct page *page,
- struct vm_area_struct *vma, unsigned long address, int exclusive)
+static void __folio_set_anon(struct folio *folio, struct vm_area_struct *vma,
+ unsigned long address, bool exclusive)
{
struct anon_vma *anon_vma = vma->anon_vma;
BUG_ON(!anon_vma);
- if (folio_test_anon(folio))
- goto out;
-
/*
- * If the page isn't exclusively mapped into this vma,
- * we must use the _oldest_ possible anon_vma for the
- * page mapping!
+ * If the folio isn't exclusive to this vma, we must use the _oldest_
+ * possible anon_vma for the folio mapping!
*/
if (!exclusive)
anon_vma = anon_vma->root;
@@ -1156,9 +1182,6 @@ static void __page_set_anon_rmap(struct folio *folio, struct page *page,
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
WRITE_ONCE(folio->mapping, (struct address_space *) anon_vma);
folio->index = linear_page_index(vma, address);
-out:
- if (exclusive)
- SetPageAnonExclusive(page);
}
/**
@@ -1207,7 +1230,7 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
atomic_t *mapped = &folio->_nr_pages_mapped;
int nr = 0, nr_pmdmapped = 0;
bool compound = flags & RMAP_COMPOUND;
- bool first = true;
+ bool first;
/* Is page being mapped by PTE? Is this its first map to be added? */
if (likely(!compound)) {
@@ -1236,24 +1259,40 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
}
}
- VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
- VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
-
if (nr_pmdmapped)
__lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr_pmdmapped);
if (nr)
__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
- if (likely(!folio_test_ksm(folio))) {
- /* address might be in next vma when migration races vma_merge */
- if (first)
- __page_set_anon_rmap(folio, page, vma, address,
- !!(flags & RMAP_EXCLUSIVE));
- else
- __page_check_anon_rmap(folio, page, vma, address);
+ if (unlikely(!folio_test_anon(folio))) {
+ VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
+ /*
+ * For a PTE-mapped large folio, we only know that the single
+ * PTE is exclusive. Further, __folio_set_anon() might not get
+ * folio->index right when not given the address of the head
+ * page.
+ */
+ VM_WARN_ON_FOLIO(folio_test_large(folio) && !compound, folio);
+ __folio_set_anon(folio, vma, address,
+ !!(flags & RMAP_EXCLUSIVE));
+ } else if (likely(!folio_test_ksm(folio))) {
+ __page_check_anon_rmap(folio, page, vma, address);
}
+ if (flags & RMAP_EXCLUSIVE)
+ SetPageAnonExclusive(page);
+ /* While PTE-mapping a THP we have a PMD and a PTE mapping. */
+ VM_WARN_ON_FOLIO((atomic_read(&page->_mapcount) > 0 ||
+ (folio_test_large(folio) && folio_entire_mapcount(folio) > 1)) &&
+ PageAnonExclusive(page), folio);
- mlock_vma_folio(folio, vma, compound);
+ /*
+ * For large folio, only mlock it if it's fully mapped to VMA. It's
+ * not easy to check whether the large folio is fully mapped to VMA
+ * here. Only mlock normal 4K folio and leave page reclaim to handle
+ * large folio.
+ */
+ if (!folio_test_large(folio))
+ mlock_vma_folio(folio, vma);
}
/**
@@ -1290,7 +1329,8 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
}
__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
- __page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+ __folio_set_anon(folio, vma, address, true);
+ SetPageAnonExclusive(&folio->page);
}
/**
@@ -1352,7 +1392,9 @@ void folio_add_file_rmap_range(struct folio *folio, struct page *page,
if (nr)
__lruvec_stat_mod_folio(folio, NR_FILE_MAPPED, nr);
- mlock_vma_folio(folio, vma, compound);
+ /* See comments in page_add_anon_rmap() */
+ if (!folio_test_large(folio))
+ mlock_vma_folio(folio, vma);
}
/**
@@ -1463,7 +1505,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
* it's only reliable while mapped.
*/
- munlock_vma_folio(folio, vma, compound);
+ munlock_vma_folio(folio, vma);
}
/*
@@ -1528,7 +1570,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
if (!(flags & TTU_IGNORE_MLOCK) &&
(vma->vm_flags & VM_LOCKED)) {
/* Restore the mlock which got missed */
- mlock_vma_folio(folio, vma, false);
+ if (!folio_test_large(folio))
+ mlock_vma_folio(folio, vma);
page_vma_mapped_walk_done(&pvmw);
ret = false;
break;
@@ -2540,22 +2583,16 @@ void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc)
*
* RMAP_COMPOUND is ignored.
*/
-void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
+void hugepage_add_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
unsigned long address, rmap_t flags)
{
- struct folio *folio = page_folio(page);
- struct anon_vma *anon_vma = vma->anon_vma;
- int first;
+ VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
- BUG_ON(!folio_test_locked(folio));
- BUG_ON(!anon_vma);
- /* address might be in next vma when migration races vma_merge */
- first = atomic_inc_and_test(&folio->_entire_mapcount);
- VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
- VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
- if (first)
- __page_set_anon_rmap(folio, page, vma, address,
- !!(flags & RMAP_EXCLUSIVE));
+ atomic_inc(&folio->_entire_mapcount);
+ if (flags & RMAP_EXCLUSIVE)
+ SetPageAnonExclusive(&folio->page);
+ VM_WARN_ON_FOLIO(folio_entire_mapcount(folio) > 1 &&
+ PageAnonExclusive(&folio->page), folio);
}
void hugepage_add_new_anon_rmap(struct folio *folio,
@@ -2565,6 +2602,7 @@ void hugepage_add_new_anon_rmap(struct folio *folio,
/* increment count (starts at -1) */
atomic_set(&folio->_entire_mapcount, 0);
folio_clear_hugetlb_restore_reserve(folio);
- __page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+ __folio_set_anon(folio, vma, address, true);
+ SetPageAnonExclusive(&folio->page);
}
#endif /* CONFIG_HUGETLB_PAGE */