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authorJérôme Glisse <jglisse@redhat.com>2019-05-14 02:19:52 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 18:47:48 +0200
commit9f454612f602d02204b1f6e86b6bec2bfb368c4b (patch)
tree5ffd615b4ed473f76e411e59f6e3e24ca07f4c37 /mm
parentmm/hmm: use reference counting for HMM struct (diff)
downloadlinux-9f454612f602d02204b1f6e86b6bec2bfb368c4b.tar.xz
linux-9f454612f602d02204b1f6e86b6bec2bfb368c4b.zip
mm/hmm: do not erase snapshot when a range is invalidated
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. Link: http://lkml.kernel.org/r/20190403193318.16478-4-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/hmm.c6
1 files changed, 0 insertions, 6 deletions
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);