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mm/rmap: factor nonlinear handling out of try_to_unmap_file()

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To merge all kinds of rmap traverse functions, try_to_unmap(),
try_to_munlock(), page_referenced() and page_mkclean(), we need to
extract common parts and separate out non-common parts.

Nonlinear handling is handled just in try_to_unmap_file() and other rmap
traverse functions doesn't care of it.  Therfore it is better to factor
nonlinear handling out of try_to_unmap_file() in order to merge all
kinds of rmap traverse functions easily.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joonsoo Kim 2014-01-21 15:49:45 -08:00 committed by Linus Torvalds
parent b854f711f6
commit 0f843c6ac3
1 changed files with 74 additions and 62 deletions
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136
mm/rmap.c
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@ -1426,6 +1426,79 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
return ret;
}
static int try_to_unmap_nonlinear(struct page *page,
struct address_space *mapping, struct vm_area_struct *vma)
{
int ret = SWAP_AGAIN;
unsigned long cursor;
unsigned long max_nl_cursor = 0;
unsigned long max_nl_size = 0;
unsigned int mapcount;
list_for_each_entry(vma,
&mapping->i_mmap_nonlinear, shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data;
if (cursor > max_nl_cursor)
max_nl_cursor = cursor;
cursor = vma->vm_end - vma->vm_start;
if (cursor > max_nl_size)
max_nl_size = cursor;
}
if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */
return SWAP_FAIL;
}
/*
* We don't try to search for this page in the nonlinear vmas,
* and page_referenced wouldn't have found it anyway. Instead
* just walk the nonlinear vmas trying to age and unmap some.
* The mapcount of the page we came in with is irrelevant,
* but even so use it as a guide to how hard we should try?
*/
mapcount = page_mapcount(page);
if (!mapcount)
return ret;
cond_resched();
max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
if (max_nl_cursor == 0)
max_nl_cursor = CLUSTER_SIZE;
do {
list_for_each_entry(vma,
&mapping->i_mmap_nonlinear, shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data;
while (cursor < max_nl_cursor &&
cursor < vma->vm_end - vma->vm_start) {
if (try_to_unmap_cluster(cursor, &mapcount,
vma, page) == SWAP_MLOCK)
ret = SWAP_MLOCK;
cursor += CLUSTER_SIZE;
vma->vm_private_data = (void *) cursor;
if ((int)mapcount <= 0)
return ret;
}
vma->vm_private_data = (void *) max_nl_cursor;
}
cond_resched();
max_nl_cursor += CLUSTER_SIZE;
} while (max_nl_cursor <= max_nl_size);
/*
* Don't loop forever (perhaps all the remaining pages are
* in locked vmas). Reset cursor on all unreserved nonlinear
* vmas, now forgetting on which ones it had fallen behind.
*/
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
vma->vm_private_data = NULL;
return ret;
}
bool is_vma_temporary_stack(struct vm_area_struct *vma)
{
int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
@ -1515,10 +1588,6 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
pgoff_t pgoff = page->index << compound_order(page);
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
unsigned long cursor;
unsigned long max_nl_cursor = 0;
unsigned long max_nl_size = 0;
unsigned int mapcount;
mutex_lock(&mapping->i_mmap_mutex);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
@ -1539,64 +1608,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
if (TTU_ACTION(flags) == TTU_MUNLOCK)
goto out;
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data;
if (cursor > max_nl_cursor)
max_nl_cursor = cursor;
cursor = vma->vm_end - vma->vm_start;
if (cursor > max_nl_size)
max_nl_size = cursor;
}
if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */
ret = SWAP_FAIL;
goto out;
}
/*
* We don't try to search for this page in the nonlinear vmas,
* and page_referenced wouldn't have found it anyway. Instead
* just walk the nonlinear vmas trying to age and unmap some.
* The mapcount of the page we came in with is irrelevant,
* but even so use it as a guide to how hard we should try?
*/
mapcount = page_mapcount(page);
if (!mapcount)
goto out;
cond_resched();
max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
if (max_nl_cursor == 0)
max_nl_cursor = CLUSTER_SIZE;
do {
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data;
while ( cursor < max_nl_cursor &&
cursor < vma->vm_end - vma->vm_start) {
if (try_to_unmap_cluster(cursor, &mapcount,
vma, page) == SWAP_MLOCK)
ret = SWAP_MLOCK;
cursor += CLUSTER_SIZE;
vma->vm_private_data = (void *) cursor;
if ((int)mapcount <= 0)
goto out;
}
vma->vm_private_data = (void *) max_nl_cursor;
}
cond_resched();
max_nl_cursor += CLUSTER_SIZE;
} while (max_nl_cursor <= max_nl_size);
/*
* Don't loop forever (perhaps all the remaining pages are
* in locked vmas). Reset cursor on all unreserved nonlinear
* vmas, now forgetting on which ones it had fallen behind.
*/
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
vma->vm_private_data = NULL;
ret = try_to_unmap_nonlinear(page, mapping, vma);
out:
mutex_unlock(&mapping->i_mmap_mutex);
return ret;