diff mbox series

[v3,03/12] mm/hmm: do not erase snapshot when a range is invalidated

Message ID 20190403193318.16478-4-jglisse@redhat.com (mailing list archive)
State New, archived
Headers show
Series Improve HMM driver API v3 | expand

Commit Message

Jerome Glisse April 3, 2019, 7:33 p.m. UTC 
From: Jérôme Glisse <jglisse@redhat.com>

Users of HMM might be using the snapshot information to do
preparatory step like dma mapping pages to a device before
checking for invalidation through hmm_vma_range_done() so
do not erase that information and assume users will do the
right thing.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
---
 mm/hmm.c | 6 ------
 1 file changed, 6 deletions(-)
diff mbox series

Patch

diff --git a/mm/hmm.c b/mm/hmm.c
index 919d78fd21c5..84e0577a912a 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -174,16 +174,10 @@  static int hmm_invalidate_range(struct hmm *hmm, bool device,
 
 	spin_lock(&hmm->lock);
 	list_for_each_entry(range, &hmm->ranges, list) {
-		unsigned long addr, idx, npages;
-
 		if (update->end < range->start || update->start >= range->end)
 			continue;
 
 		range->valid = false;
-		addr = max(update->start, range->start);
-		idx = (addr - range->start) >> PAGE_SHIFT;
-		npages = (min(range->end, update->end) - addr) >> PAGE_SHIFT;
-		memset(&range->pfns[idx], 0, sizeof(*range->pfns) * npages);
 	}
 	spin_unlock(&hmm->lock);