diff options
| author | Minchan Kim <[email protected]> | 2017-11-15 17:33:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2017-11-15 18:21:02 -0800 |
| commit | 539a6fea7fdcade532bd3e77be2862a683f8f0c9 (patch) | |
| tree | f3255c208ee4803cea857226b880a9838eccd2c8 | |
| parent | 23c47d2ada9f96731492a67b28c0072715075baa (diff) | |
mm, swap: introduce SWP_SYNCHRONOUS_IO
If rw-page based fast storage is used for swap devices, we need to
detect it to enhance swap IO operations. This patch is preparation for
optimizing of swap-in operation with next patch.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Ilya Dryomov <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Ross Zwisler <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Huang Ying <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | include/linux/swap.h | 3 | ||||
| -rw-r--r-- | mm/swapfile.c | 3 |
2 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index f02fb5db8914..933d7c0c3542 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -171,8 +171,9 @@ enum { SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */ + SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */ /* add others here before... */ - SWP_SCANNING = (1 << 11), /* refcount in scan_swap_map */ + SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */ }; #define SWAP_CLUSTER_MAX 32UL diff --git a/mm/swapfile.c b/mm/swapfile.c index e47a21e64764..cb08fa65819f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3169,6 +3169,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) p->flags |= SWP_STABLE_WRITES; + if (bdi_cap_synchronous_io(inode_to_bdi(inode))) + p->flags |= SWP_SYNCHRONOUS_IO; + if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { int cpu; unsigned long ci, nr_cluster; |