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author | Hugh Dickins <hughd@google.com> | 2011-08-03 16:21:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-03 14:25:24 -1000 |
commit | 6922c0c7abd387374255801f7739624867e8acad (patch) | |
tree | 851ec456dbca49ee78c302fd62839e9889a75290 /drivers/dma | |
parent | aa3b189551ad8e5cc1d9c663735c131650238278 (diff) | |
download | talos-op-linux-6922c0c7abd387374255801f7739624867e8acad.tar.gz talos-op-linux-6922c0c7abd387374255801f7739624867e8acad.zip |
tmpfs: convert shmem_writepage and enable swap
Convert shmem_writepage() to use shmem_delete_from_page_cache() to use
shmem_radix_tree_replace() to substitute swap entry for page pointer
atomically in the radix tree.
As with shmem_add_to_page_cache(), it's not entirely satisfactory to be
copying such code from delete_from_swap_cache, but again judged easier
to sell than making its other callers go through the extras.
Remove the toy implementation's shmem_put_swap() and shmem_get_swap(),
now unreferenced, and the hack to disable swap: it's now good to go.
The way things have worked out, info->lock no longer helps to guard the
shmem_swaplist: we increment swapped under shmem_swaplist_mutex only.
That global mutex exclusion between shmem_writepage() and shmem_unuse()
is not pretty, and we ought to find another way; but it's been forced on
us by recent race discoveries, not a consequence of this patchset.
And what has become of the WARN_ON_ONCE(1) free_swap_and_cache() if a
swap entry was found already present? That's no longer possible, the
(unknown) one inserting this page into filecache would hit the swap
entry occupying that slot.
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/dma')
0 files changed, 0 insertions, 0 deletions