The patch titled
mlock: backout locked_vm adjustment during mmap()
has been added to the -mm tree. Its filename is
mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap.patch
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------------------------------------------------------
Subject: mlock: backout locked_vm adjustment during mmap()
From: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Backout mmap() path locked_vm accounting adjustment from the "handle
mlocked pages during map/remap/unmap" patch. Will resubmit as separate
patch with its own description.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mlock.c | 19 ++++++-------------
mm/mmap.c | 19 ++++++++-----------
2 files changed, 14 insertions(+), 24 deletions(-)
diff -puN mm/mlock.c~mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap mm/mlock.c
--- a/mm/mlock.c~mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap
+++ a/mm/mlock.c
@@ -246,7 +246,7 @@ int mlock_vma_pages_range(struct vm_area
unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
- int nr_pages = (end - start) / PAGE_SIZE;
+ int error = 0;
BUG_ON(!(vma->vm_flags & VM_LOCKED));
/*
@@ -259,8 +259,7 @@ int mlock_vma_pages_range(struct vm_area
is_vm_hugetlb_page(vma) ||
vma == get_gate_vma(current))) {
downgrade_write(&mm->mmap_sem);
- nr_pages = __mlock_vma_pages_range(vma, start, end, 1);
-
+ error = __mlock_vma_pages_range(vma, start, end, 1);
up_read(&mm->mmap_sem);
/* vma can change or disappear */
down_write(&mm->mmap_sem);
@@ -268,22 +267,20 @@ int mlock_vma_pages_range(struct vm_area
/* non-NULL vma must contain @start, but need to check @end */
if (!vma || end > vma->vm_end)
return -EAGAIN;
- return nr_pages;
+ return error;
}
/*
* User mapped kernel pages or huge pages:
* make these pages present to populate the ptes, but
- * fall thru' to reset VM_LOCKED--no need to unlock, and
- * return nr_pages so these don't get counted against task's
- * locked limit. huge pages are already counted against
- * locked vm limit.
+ * fall thru' to reset VM_LOCKED so we don't try to munlock
+ * this vma during munmap()/munlock().
*/
make_pages_present(start, end);
no_mlock:
vma->vm_flags &= ~VM_LOCKED; /* and don't come back! */
- return nr_pages; /* pages NOT mlocked */
+ return error;
}
@@ -372,10 +369,6 @@ success:
downgrade_write(&mm->mmap_sem);
ret = __mlock_vma_pages_range(vma, start, end, 1);
- if (ret > 0) {
- mm->locked_vm -= ret;
- ret = 0;
- }
/*
* Need to reacquire mmap sem in write mode, as our callers
* expect this. We have no support for atomically upgrading
diff -puN mm/mmap.c~mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap mm/mmap.c
--- a/mm/mmap.c~mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap
+++ a/mm/mmap.c
@@ -1224,10 +1224,10 @@ out:
/*
* makes pages present; downgrades, drops, reacquires mmap_sem
*/
- int nr_pages = mlock_vma_pages_range(vma, addr, addr + len);
- if (nr_pages < 0)
- return nr_pages; /* vma gone! */
- mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages;
+ int error = mlock_vma_pages_range(vma, addr, addr + len);
+ if (error < 0)
+ return error; /* vma gone! */
+ mm->locked_vm += (len >> PAGE_SHIFT);
} else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
make_pages_present(addr, addr + len);
return addr;
@@ -1702,8 +1702,7 @@ find_extend_vma(struct mm_struct *mm, un
if (!prev || expand_stack(prev, addr))
return NULL;
if (prev->vm_flags & VM_LOCKED) {
- int nr_pages = mlock_vma_pages_range(prev, addr, prev->vm_end);
- if (nr_pages < 0)
+ if (mlock_vma_pages_range(prev, addr, prev->vm_end) < 0)
return NULL; /* vma gone! */
}
return prev;
@@ -1732,8 +1731,7 @@ find_extend_vma(struct mm_struct * mm, u
if (expand_stack(vma, addr))
return NULL;
if (vma->vm_flags & VM_LOCKED) {
- int nr_pages = mlock_vma_pages_range(vma, addr, start);
- if (nr_pages < 0)
+ if (mlock_vma_pages_range(vma, addr, start) < 0)
return NULL; /* vma gone! */
}
return vma;
@@ -2068,9 +2066,8 @@ unsigned long do_brk(unsigned long addr,
out:
mm->total_vm += len >> PAGE_SHIFT;
if (flags & VM_LOCKED) {
- int nr_pages = mlock_vma_pages_range(vma, addr, addr + len);
- if (nr_pages >= 0)
- mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages;
+ if (mlock_vma_pages_range(vma, addr, addr + len) >= 0)
+ mm->locked_vm += (len >> PAGE_SHIFT);
}
return addr;
}
_
Patches currently in -mm which might be from lee.schermerhorn@xxxxxx are
vmscan-use-an-indexed-array-for-lru-variables.patch
define-page_file_cache-function.patch
vmscan-split-lru-lists-into-anon-file-sets.patch
pageflag-helpers-for-configed-out-flags.patch
unevictable-lru-infrastructure.patch
unevictable-lru-infrastructure-nommu-fix.patch
unevictable-lru-infrastructure-remember-pages-active-state.patch
unevictable-lru-infrastructure-defer-vm-event-counting.patch
unevictable-infrastructure-lru-add-event-counting-with-statistics.patch
unevictable-lru-page-statistics.patch
ramfs-and-ram-disk-pages-are-unevictable.patch
shm_locked-pages-are-unevictable.patch
shm_locked-pages-are-unevictable-add-event-counts-to-list-scan.patch
mlock-mlocked-pages-are-unevictable.patch
mlock-mlocked-pages-are-unevictable-fix.patch
doc-unevictable-lru-and-mlocked-pages-documentation.patch
doc-unevictable-lru-and-mlocked-pages-documentation-update.patch
doc-unevictable-lru-and-mlocked-pages-documentation-update-2.patch
mlock-downgrade-mmap-sem-while-populating-mlocked-regions.patch
mmap-handle-mlocked-pages-during-map-remap-unmap.patch
mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-fix-__mlock_vma_pages_range-comment-block.patch
mmap-handle-mlocked-pages-during-map-remap-unmap-mlock-backout-locked_vm-adjustment-during-mmap.patch
vmstat-mlocked-pages-statistics.patch
vmstat-mlocked-pages-statistics-mlocked-pages-add-event-counting-with-statistics.patch
swap-cull-unevictable-pages-in-fault-path.patch
vmscan-unevictable-lru-scan-sysctl.patch
mlock-count-attempts-to-free-mlocked-page-2.patch
mlock-resubmit-locked_vm-adjustment-as-separate-patch.patch
mlock-fix-return-value-for-munmap-mlock-vma-race.patch
mlock-update-locked_vm-on-munmap-of-mlocked-region.patch
mlock-revert-mainline-handling-of-mlock-error-return.patch
mlock-make-mlock-error-return-posixly-correct.patch
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