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mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end

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In order to allow sleeping during invalidate_page mmu notifier calls, we
need to avoid calling when holding the PT lock.  In addition to its direct
calls, invalidate_page can also be called as a substitute for a change_pte
call, in case the notifier client hasn't implemented change_pte.

This patch drops the invalidate_page call from change_pte, and instead
wraps all calls to change_pte with invalidate_range_start and
invalidate_range_end calls.

Note that change_pte still cannot sleep after this patch, and that clients
implementing change_pte should not take action on it in case the number of
outstanding invalidate_range_start calls is larger than one, otherwise
they might miss a later invalidation.

Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Cc: Andrea Arcangeli <andrea@qumranet.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Haggai Eran <haggaie@mellanox.com>
Cc: Shachar Raindel <raindel@mellanox.com>
Cc: Liran Liss <liranl@mellanox.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Hugh Dickins <hughd@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:
Haggai Eran
2012-10-08 16:33:35 -07:00
committed by Linus Torvalds
parent 2ec74c3ef2
commit 6bdb913f0a
4 changed files with 36 additions and 14 deletions
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18
mm/memory.c
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@@ -2527,6 +2527,9 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
int ret = 0;
int page_mkwrite = 0;
struct page *dirty_page = NULL;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
bool mmun_called = false; /* For mmu_notifiers */
old_page = vm_normal_page(vma, address, orig_pte);
if (!old_page) {
@@ -2704,6 +2707,11 @@ gotten:
if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
goto oom_free_new;
mmun_start = address & PAGE_MASK;
mmun_end = (address & PAGE_MASK) + PAGE_SIZE;
mmun_called = true;
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
/*
* Re-check the pte - we dropped the lock
*/
@@ -2766,14 +2774,12 @@ gotten:
} else
mem_cgroup_uncharge_page(new_page);
if (new_page)
page_cache_release(new_page);
unlock:
pte_unmap_unlock(page_table, ptl);
if (new_page) {
if (new_page == old_page)
/* cow happened, notify before releasing old_page */
mmu_notifier_invalidate_page(mm, address);
page_cache_release(new_page);
}
if (mmun_called)
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
if (old_page) {
/*
* Don't let another task, with possibly unlocked vma,