| Message ID | alpine.LSU.2.11.1811261531200.2275@eggly.anvils (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | huge_memory,khugepaged tmpfs split/collapse fixes | expand |
On Mon, Nov 26, 2018 at 03:33:13PM -0800, Hugh Dickins wrote: > collapse_shmem()'s xas_nomem() is very unlikely to fail, but it is > rightly given a failure path, so move the whole xas_create_range() block > up before __SetPageLocked(new_page): so that it does not need to remember > to unlock_page(new_page). Add the missing mem_cgroup_cancel_charge(), > and set (currently unused) result to SCAN_FAIL rather than SCAN_SUCCEED. > > Fixes: 77da9389b9d5 ("mm: Convert collapse_shmem to XArray") > Signed-off-by: Hugh Dickins <hughd@kernel.org> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 2c5fe4f7a0c6..8e2ff195ecb3 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1329,6 +1329,20 @@ static void collapse_shmem(struct mm_struct *mm, goto out; } + /* This will be less messy when we use multi-index entries */ + do { + xas_lock_irq(&xas); + xas_create_range(&xas); + if (!xas_error(&xas)) + break; + xas_unlock_irq(&xas); + if (!xas_nomem(&xas, GFP_KERNEL)) { + mem_cgroup_cancel_charge(new_page, memcg, true); + result = SCAN_FAIL; + goto out; + } + } while (1); + __SetPageLocked(new_page); __SetPageSwapBacked(new_page); new_page->index = start; @@ -1340,17 +1354,6 @@ static void collapse_shmem(struct mm_struct *mm, * be able to map it or use it in another way until we unlock it. */ - /* This will be less messy when we use multi-index entries */ - do { - xas_lock_irq(&xas); - xas_create_range(&xas); - if (!xas_error(&xas)) - break; - xas_unlock_irq(&xas); - if (!xas_nomem(&xas, GFP_KERNEL)) - goto out; - } while (1); - xas_set(&xas, start); for (index = start; index < end; index++) { struct page *page = xas_next(&xas);
collapse_shmem()'s xas_nomem() is very unlikely to fail, but it is rightly given a failure path, so move the whole xas_create_range() block up before __SetPageLocked(new_page): so that it does not need to remember to unlock_page(new_page). Add the missing mem_cgroup_cancel_charge(), and set (currently unused) result to SCAN_FAIL rather than SCAN_SUCCEED. Fixes: 77da9389b9d5 ("mm: Convert collapse_shmem to XArray") Signed-off-by: Hugh Dickins <hughd@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- mm/khugepaged.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)