From: Minchan Kim <minchan@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team <kernel-team@lge.com>, Christoph Hellwig <hch@lst.de>,
Minchan Kim <minchan@kernel.org>, Hugh Dickins <hughd@google.com>
Subject: [PATCH v2 3/4] mm:swap: introduce SWP_SYNCHRONOUS_IO
Date: Wed, 20 Sep 2017 14:43:24 +0900 [thread overview]
Message-ID: <1505886205-9671-4-git-send-email-minchan@kernel.org> (raw)
In-Reply-To: <1505886205-9671-1-git-send-email-minchan@kernel.org>
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.
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
include/linux/swap.h | 3 ++-
mm/swapfile.c | 3 +++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8a807292037f..fbb33919d1c6 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -170,8 +170,9 @@ 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 bf91dc9e7a79..1305591cde4d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3168,6 +3168,9 @@ 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;
--
2.7.4
--
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next prev parent reply other threads:[~2017-09-20 5:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-20 5:43 [PATCH v2 0/4] skip swapcache for super fast device Minchan Kim
2017-09-20 5:43 ` [PATCH v2 1/4] zram: set BDI_CAP_STABLE_WRITES once Minchan Kim
2017-09-20 5:43 ` [PATCH v2 2/4] bdi: introduce BDI_CAP_SYNCHRONOUS_IO Minchan Kim
2017-09-20 5:43 ` Minchan Kim [this message]
2017-09-20 5:43 ` [PATCH v2 4/4] mm:swap: skip swapcache for swapin of synchronous device Minchan Kim
2017-09-29 8:51 ` huang ying
2017-10-09 1:26 ` huang ying
2017-10-10 0:34 ` Minchan Kim
2017-10-10 1:10 ` Huang, Ying
-- strict thread matches above, loose matches on Subject: below --
2017-09-19 7:09 [PATCH v2 0/4] skip swapcache for super fast device Minchan Kim
2017-09-19 7:10 ` [PATCH v2 3/4] mm:swap: introduce SWP_SYNCHRONOUS_IO Minchan Kim
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