A mechanical rename of the mm_struct->map_count.
While at it update the vma_count BUG_ON() in exit_mmap() to a WARN_ON_ONCE; no other functional change is intended.
The name "map_count" is ambiguous within the memory management subsystem, as it can be confused with the folio/page->_mapcount field, which tracks PTE references.
The new name, vma_count, is more precise as this field has always counted the number of vm_area_structs associated with an mm_struct.
Cc: Andrew Morton akpm@linux-foundation.org Cc: David Hildenbrand david@redhat.com Cc: "Liam R. Howlett" Liam.Howlett@oracle.com Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com Cc: Mike Rapoport rppt@kernel.org Cc: Minchan Kim minchan@kernel.org Cc: Pedro Falcato pfalcato@suse.de Reviewed-by: Pedro Falcato pfalcato@suse.de Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com Signed-off-by: Kalesh Singh kaleshsingh@google.com
---
Changes in v3: - Change vma_count BUG_ON() in exit_mmap() to WARN_ON_ONCE, per David and Lorenzo - Collect Reviewed-by tags
fs/binfmt_elf.c | 2 +- fs/coredump.c | 2 +- include/linux/mm_types.h | 2 +- kernel/fork.c | 2 +- mm/debug.c | 2 +- mm/mmap.c | 10 +++++----- mm/nommu.c | 6 +++--- mm/vma.c | 24 ++++++++++++------------ tools/testing/vma/vma.c | 32 ++++++++++++++++---------------- tools/testing/vma/vma_internal.h | 6 +++--- 10 files changed, 44 insertions(+), 44 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index e4653bb99946..a5acfe97612d 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1660,7 +1660,7 @@ static int fill_files_note(struct memelfnote *note, struct coredump_params *cprm data[0] = count; data[1] = PAGE_SIZE; /* - * Count usually is less than mm->map_count, + * Count usually is less than mm->vma_count, * we need to move filenames down. */ n = cprm->vma_count - count; diff --git a/fs/coredump.c b/fs/coredump.c index b5fc06a092a4..5e0859813141 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -1733,7 +1733,7 @@ static bool dump_vma_snapshot(struct coredump_params *cprm)
cprm->vma_data_size = 0; gate_vma = get_gate_vma(mm); - cprm->vma_count = mm->map_count + (gate_vma ? 1 : 0); + cprm->vma_count = mm->vma_count + (gate_vma ? 1 : 0);
cprm->vma_meta = kvmalloc_array(cprm->vma_count, sizeof(*cprm->vma_meta), GFP_KERNEL); if (!cprm->vma_meta) { diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4e5d59997e4a..97e0541cd415 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1078,7 +1078,7 @@ struct mm_struct { #ifdef CONFIG_MMU atomic_long_t pgtables_bytes; /* size of all page tables */ #endif - int map_count; /* number of VMAs */ + int vma_count; /* number of VMAs */
spinlock_t page_table_lock; /* Protects page tables and some * counters diff --git a/kernel/fork.c b/kernel/fork.c index 3da0f08615a9..c8d59042b34f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1038,7 +1038,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mmap_init_lock(mm); INIT_LIST_HEAD(&mm->mmlist); mm_pgtables_bytes_init(mm); - mm->map_count = 0; + mm->vma_count = 0; mm->locked_vm = 0; atomic64_set(&mm->pinned_vm, 0); memset(&mm->rss_stat, 0, sizeof(mm->rss_stat)); diff --git a/mm/debug.c b/mm/debug.c index 64ddb0c4b4be..a35e2912ae53 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -204,7 +204,7 @@ void dump_mm(const struct mm_struct *mm) mm->pgd, atomic_read(&mm->mm_users), atomic_read(&mm->mm_count), mm_pgtables_bytes(mm), - mm->map_count, + mm->vma_count, mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm, (u64)atomic64_read(&mm->pinned_vm), mm->data_vm, mm->exec_vm, mm->stack_vm, diff --git a/mm/mmap.c b/mm/mmap.c index d9ea029cd018..b4eda47b88d8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1305,7 +1305,7 @@ void exit_mmap(struct mm_struct *mm) vma = vma_next(&vmi); } while (vma && likely(!xa_is_zero(vma)));
- BUG_ON(count != mm->map_count); + WARN_ON_ONCE(count != mm->vma_count);
trace_exit_mmap(mm); destroy: @@ -1508,13 +1508,13 @@ static int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; */ int vma_count_remaining(const struct mm_struct *mm) { - const int map_count = mm->map_count; + const int vma_count = mm->vma_count; const int max_count = READ_ONCE(sysctl_max_map_count);
- if (map_count >= max_count) + if (vma_count >= max_count) return 0;
- return max_count - map_count; + return max_count - vma_count; }
#ifdef CONFIG_SYSCTL @@ -1828,7 +1828,7 @@ __latent_entropy int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) */ vma_iter_bulk_store(&vmi, tmp);
- mm->map_count++; + mm->vma_count++;
if (tmp->vm_ops && tmp->vm_ops->open) tmp->vm_ops->open(tmp); diff --git a/mm/nommu.c b/mm/nommu.c index 22e55e7c69c4..b375d3e00d0c 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -577,7 +577,7 @@ static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm)
static void cleanup_vma_from_mm(struct vm_area_struct *vma) { - vma->vm_mm->map_count--; + vma->vm_mm->vma_count--; /* remove the VMA from the mapping */ if (vma->vm_file) { struct address_space *mapping; @@ -1199,7 +1199,7 @@ unsigned long do_mmap(struct file *file, goto error_just_free;
setup_vma_to_mm(vma, current->mm); - current->mm->map_count++; + current->mm->vma_count++; /* add the VMA to the tree */ vma_iter_store_new(&vmi, vma);
@@ -1367,7 +1367,7 @@ static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, setup_vma_to_mm(vma, mm); setup_vma_to_mm(new, mm); vma_iter_store_new(vmi, new); - mm->map_count++; + mm->vma_count++; return 0;
err_vmi_preallocate: diff --git a/mm/vma.c b/mm/vma.c index 96ba37721002..b35a4607cde4 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -352,7 +352,7 @@ static void vma_complete(struct vma_prepare *vp, struct vma_iterator *vmi, * (it may either follow vma or precede it). */ vma_iter_store_new(vmi, vp->insert); - mm->map_count++; + mm->vma_count++; }
if (vp->anon_vma) { @@ -383,7 +383,7 @@ static void vma_complete(struct vma_prepare *vp, struct vma_iterator *vmi, } if (vp->remove->anon_vma) anon_vma_merge(vp->vma, vp->remove); - mm->map_count--; + mm->vma_count--; mpol_put(vma_policy(vp->remove)); if (!vp->remove2) WARN_ON_ONCE(vp->vma->vm_end < vp->remove->vm_end); @@ -683,13 +683,13 @@ void validate_mm(struct mm_struct *mm) } #endif /* Check for a infinite loop */ - if (++i > mm->map_count + 10) { + if (++i > mm->vma_count + 10) { i = -1; break; } } - if (i != mm->map_count) { - pr_emerg("map_count %d vma iterator %d\n", mm->map_count, i); + if (i != mm->vma_count) { + pr_emerg("vma_count %d vma iterator %d\n", mm->vma_count, i); bug = 1; } VM_BUG_ON_MM(bug, mm); @@ -1266,7 +1266,7 @@ static void vms_complete_munmap_vmas(struct vma_munmap_struct *vms, struct mm_struct *mm;
mm = current->mm; - mm->map_count -= vms->vma_count; + mm->vma_count -= vms->vma_count; mm->locked_vm -= vms->locked_vm; if (vms->unlock) mmap_write_downgrade(mm); @@ -1340,14 +1340,14 @@ static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, if (vms->start > vms->vma->vm_start) {
/* - * Make sure that map_count on return from munmap() will + * Make sure that vma_count on return from munmap() will * not exceed its limit; but let map_count go just above * its limit temporarily, to help free resources as expected. */ if (vms->end < vms->vma->vm_end && !vma_count_remaining(vms->vma->vm_mm)) { error = -ENOMEM; - goto map_count_exceeded; + goto vma_count_exceeded; }
/* Don't bother splitting the VMA if we can't unmap it anyway */ @@ -1461,7 +1461,7 @@ static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, modify_vma_failed: reattach_vmas(mas_detach); start_split_failed: -map_count_exceeded: +vma_count_exceeded: return error; }
@@ -1795,7 +1795,7 @@ int vma_link(struct mm_struct *mm, struct vm_area_struct *vma) vma_start_write(vma); vma_iter_store_new(&vmi, vma); vma_link_file(vma); - mm->map_count++; + mm->vma_count++; validate_mm(mm); return 0; } @@ -2512,7 +2512,7 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap) /* Lock the VMA since it is modified after insertion into VMA tree */ vma_start_write(vma); vma_iter_store_new(vmi, vma); - map->mm->map_count++; + map->mm->vma_count++; vma_link_file(vma);
/* @@ -2835,7 +2835,7 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) goto mas_store_fail;
- mm->map_count++; + mm->vma_count++; validate_mm(mm); out: perf_event_mmap(vma); diff --git a/tools/testing/vma/vma.c b/tools/testing/vma/vma.c index 656e1c75b711..69fa7d14a6c2 100644 --- a/tools/testing/vma/vma.c +++ b/tools/testing/vma/vma.c @@ -261,7 +261,7 @@ static int cleanup_mm(struct mm_struct *mm, struct vma_iterator *vmi) }
mtree_destroy(&mm->mm_mt); - mm->map_count = 0; + mm->vma_count = 0; return count; }
@@ -500,7 +500,7 @@ static bool test_merge_new(void) INIT_LIST_HEAD(&vma_d->anon_vma_chain); list_add(&dummy_anon_vma_chain_d.same_vma, &vma_d->anon_vma_chain); ASSERT_FALSE(merged); - ASSERT_EQ(mm.map_count, 4); + ASSERT_EQ(mm.vma_count, 4);
/* * Merge BOTH sides. @@ -519,7 +519,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 3); + ASSERT_EQ(mm.vma_count, 3);
/* * Merge to PREVIOUS VMA. @@ -536,7 +536,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 3); + ASSERT_EQ(mm.vma_count, 3);
/* * Merge to NEXT VMA. @@ -555,7 +555,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 6); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 3); + ASSERT_EQ(mm.vma_count, 3);
/* * Merge BOTH sides. @@ -573,7 +573,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
/* * Merge to NEXT VMA. @@ -591,7 +591,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 0xa); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
/* * Merge BOTH sides. @@ -608,7 +608,7 @@ static bool test_merge_new(void) ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_EQ(vma->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 1); + ASSERT_EQ(mm.vma_count, 1);
/* * Final state. @@ -967,7 +967,7 @@ static bool test_vma_merge_new_with_close(void) ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_EQ(vma->vm_ops, &vm_ops); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
cleanup_mm(&mm, &vmi); return true; @@ -1017,7 +1017,7 @@ static bool test_merge_existing(void) ASSERT_EQ(vma->vm_pgoff, 2); ASSERT_TRUE(vma_write_started(vma)); ASSERT_TRUE(vma_write_started(vma_next)); - ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
/* Clear down and reset. */ ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); @@ -1045,7 +1045,7 @@ static bool test_merge_existing(void) ASSERT_EQ(vma_next->vm_pgoff, 2); ASSERT_EQ(vma_next->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma_next)); - ASSERT_EQ(mm.map_count, 1); + ASSERT_EQ(mm.vma_count, 1);
/* Clear down and reset. We should have deleted vma. */ ASSERT_EQ(cleanup_mm(&mm, &vmi), 1); @@ -1079,7 +1079,7 @@ static bool test_merge_existing(void) ASSERT_EQ(vma->vm_pgoff, 6); ASSERT_TRUE(vma_write_started(vma_prev)); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
/* Clear down and reset. */ ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); @@ -1108,7 +1108,7 @@ static bool test_merge_existing(void) ASSERT_EQ(vma_prev->vm_pgoff, 0); ASSERT_EQ(vma_prev->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma_prev)); - ASSERT_EQ(mm.map_count, 1); + ASSERT_EQ(mm.vma_count, 1);
/* Clear down and reset. We should have deleted vma. */ ASSERT_EQ(cleanup_mm(&mm, &vmi), 1); @@ -1138,7 +1138,7 @@ static bool test_merge_existing(void) ASSERT_EQ(vma_prev->vm_pgoff, 0); ASSERT_EQ(vma_prev->anon_vma, &dummy_anon_vma); ASSERT_TRUE(vma_write_started(vma_prev)); - ASSERT_EQ(mm.map_count, 1); + ASSERT_EQ(mm.vma_count, 1);
/* Clear down and reset. We should have deleted prev and next. */ ASSERT_EQ(cleanup_mm(&mm, &vmi), 1); @@ -1540,7 +1540,7 @@ static bool test_merge_extend(void) ASSERT_EQ(vma->vm_end, 0x4000); ASSERT_EQ(vma->vm_pgoff, 0); ASSERT_TRUE(vma_write_started(vma)); - ASSERT_EQ(mm.map_count, 1); + ASSERT_EQ(mm.vma_count, 1);
cleanup_mm(&mm, &vmi); return true; @@ -1652,7 +1652,7 @@ static bool test_mmap_region_basic(void) 0x24d, NULL); ASSERT_EQ(addr, 0x24d000);
- ASSERT_EQ(mm.map_count, 2); + ASSERT_EQ(mm.vma_count, 2);
for_each_vma(vmi, vma) { if (vma->vm_start == 0x300000) { diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h index 70f11163ab72..84760d901656 100644 --- a/tools/testing/vma/vma_internal.h +++ b/tools/testing/vma/vma_internal.h @@ -261,7 +261,7 @@ typedef struct {
struct mm_struct { struct maple_tree mm_mt; - int map_count; /* number of VMAs */ + int vma_count; /* number of VMAs */ unsigned long total_vm; /* Total pages mapped */ unsigned long locked_vm; /* Pages that have PG_mlocked set */ unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ @@ -1487,10 +1487,10 @@ static inline int do_munmap(struct mm_struct *, unsigned long, size_t, /* Helper to get VMA count capacity */ static int vma_count_remaining(const struct mm_struct *mm) { - const int map_count = mm->map_count; + const int vma_count = mm->vma_count; const int max_count = sysctl_max_map_count;
- return (max_count > map_count) ? (max_count - map_count) : 0; + return (max_count > vma_count) ? (max_count - vma_count) : 0; }
#endif /* __MM_VMA_INTERNAL_H */