mm, thp: remove compound_lock()

We are going to use migration entries to stabilize page counts.  It
means we don't need compound_lock() for that.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2016-01-15 16:53:07 -08:00 committed by Linus Torvalds
parent f765f54059
commit 3ac808fdd2
4 changed files with 4 additions and 57 deletions

View File

@ -410,41 +410,6 @@ static inline int is_vmalloc_or_module_addr(const void *x)
extern void kvfree(const void *addr);
static inline void compound_lock(struct page *page)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
VM_BUG_ON_PAGE(PageSlab(page), page);
bit_spin_lock(PG_compound_lock, &page->flags);
#endif
}
static inline void compound_unlock(struct page *page)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
VM_BUG_ON_PAGE(PageSlab(page), page);
bit_spin_unlock(PG_compound_lock, &page->flags);
#endif
}
static inline unsigned long compound_lock_irqsave(struct page *page)
{
unsigned long uninitialized_var(flags);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
local_irq_save(flags);
compound_lock(page);
#endif
return flags;
}
static inline void compound_unlock_irqrestore(struct page *page,
unsigned long flags)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
compound_unlock(page);
local_irq_restore(flags);
#endif
}
/*
* The atomic page->_mapcount, starts from -1: so that transitions
* both from it and to it can be tracked, using atomic_inc_and_test

View File

@ -101,9 +101,6 @@ enum pageflags {
#ifdef CONFIG_MEMORY_FAILURE
PG_hwpoison, /* hardware poisoned page. Don't touch */
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
PG_compound_lock,
#endif
#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
PG_young,
PG_idle,
@ -613,12 +610,6 @@ static inline void ClearPageSlabPfmemalloc(struct page *page)
#define __PG_MLOCKED 0
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define __PG_COMPOUND_LOCK (1 << PG_compound_lock)
#else
#define __PG_COMPOUND_LOCK 0
#endif
/*
* Flags checked when a page is freed. Pages being freed should not have
* these flags set. It they are, there is a problem.
@ -628,8 +619,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page)
1 << PG_private | 1 << PG_private_2 | \
1 << PG_writeback | 1 << PG_reserved | \
1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
1 << PG_unevictable | __PG_MLOCKED | \
__PG_COMPOUND_LOCK)
1 << PG_unevictable | __PG_MLOCKED)
/*
* Flags checked when a page is prepped for return by the page allocator.

View File

@ -40,9 +40,6 @@ static const struct trace_print_flags pageflag_names[] = {
#ifdef CONFIG_MEMORY_FAILURE
{1UL << PG_hwpoison, "hwpoison" },
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
{1UL << PG_compound_lock, "compound_lock" },
#endif
#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
{1UL << PG_young, "young" },
{1UL << PG_idle, "idle" },

View File

@ -2433,9 +2433,7 @@ void __memcg_kmem_uncharge(struct page *page, int order)
/*
* Because tail pages are not marked as "used", set it. We're under
* zone->lru_lock, 'splitting on pmd' and compound_lock.
* charge/uncharge will be never happen and move_account() is done under
* compound_lock(), so we don't have to take care of races.
* zone->lru_lock and migration entries setup in all page mappings.
*/
void mem_cgroup_split_huge_fixup(struct page *head)
{
@ -4507,9 +4505,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
* @from: mem_cgroup which the page is moved from.
* @to: mem_cgroup which the page is moved to. @from != @to.
*
* The caller must confirm following.
* - page is not on LRU (isolate_page() is useful.)
* - compound_lock is held when nr_pages > 1
* The caller must make sure the page is not on LRU (isolate_page() is useful.)
*
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
* from old cgroup.
@ -4868,8 +4864,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
struct page *page;
/*
* We don't take compound_lock() here but no race with splitting thp
* happens because:
* No race with splitting thp happens because:
* - if pmd_trans_huge_lock() returns 1, the relevant thp is not
* under splitting, which means there's no concurrent thp split,
* - if another thread runs into split_huge_page() just after we