From: Andreas Gerstmayr <andreas.gerstmayr@catalysts.cc>
To: <ceph-devel@vger.kernel.org>
Cc: <andreas.gerstmayr@gmail.com>,
Andreas Gerstmayr <andreas.gerstmayr@catalysts.cc>,
"Yan, Zheng" <zyan@redhat.com>, Sage Weil <sage@redhat.com>,
Ilya Dryomov <idryomov@gmail.com>,
Jonathan Corbet <corbet@lwn.net>, <linux-doc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH v4] ceph: set io_pages bdi hint
Date: Tue, 10 Jan 2017 14:17:56 +0100 [thread overview]
Message-ID: <1484054308-4901-1-git-send-email-andreas.gerstmayr@catalysts.cc> (raw)
In-Reply-To: <7C9D4085-7D14-4BFB-B675-8FE3C661B1C3@redhat.com>
This patch sets the io_pages bdi hint based on the rsize mount option.
Without this patch large buffered reads (request size > max readahead)
are processed sequentially in chunks of the readahead size (i.e. read
requests are sent out up to the readahead size, then the
do_generic_file_read() function waits until the first page is received).
With this patch read requests are sent out at once up to the size
specified in the rsize mount option (default: 64 MB).
Signed-off-by: Andreas Gerstmayr <andreas.gerstmayr@catalysts.cc>
---
Changes in v4:
- update documentation
(Note: This patch depends on kernel version 4.10-rc1)
Documentation/filesystems/ceph.txt | 5 ++---
fs/ceph/super.c | 8 ++++++++
fs/ceph/super.h | 4 ++--
3 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt
index f5306ee..0b302a1 100644
--- a/Documentation/filesystems/ceph.txt
+++ b/Documentation/filesystems/ceph.txt
@@ -98,11 +98,10 @@ Mount Options
size.
rsize=X
- Specify the maximum read size in bytes. By default there is no
- maximum.
+ Specify the maximum read size in bytes. Default: 64 MB.
rasize=X
- Specify the maximum readahead.
+ Specify the maximum readahead. Default: 8 MB.
mount_timeout=X
Specify the timeout value for mount (in seconds), in the case
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 6bd20d7..a0a0b6d 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -952,6 +952,14 @@ static int ceph_register_bdi(struct super_block *sb,
fsc->backing_dev_info.ra_pages =
VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
+ if (fsc->mount_options->rsize > fsc->mount_options->rasize &&
+ fsc->mount_options->rsize >= PAGE_SIZE)
+ fsc->backing_dev_info.io_pages =
+ (fsc->mount_options->rsize + PAGE_SIZE - 1)
+ >> PAGE_SHIFT;
+ else if (fsc->mount_options->rsize == 0)
+ fsc->backing_dev_info.io_pages = ULONG_MAX;
+
err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld",
atomic_long_inc_return(&bdi_seq));
if (!err)
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 3373b61..88b2e6e 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -45,8 +45,8 @@
#define ceph_test_mount_opt(fsc, opt) \
(!!((fsc)->mount_options->flags & CEPH_MOUNT_OPT_##opt))
-#define CEPH_RSIZE_DEFAULT 0 /* max read size */
-#define CEPH_RASIZE_DEFAULT (8192*1024) /* readahead */
+#define CEPH_RSIZE_DEFAULT (64*1024*1024) /* max read size */
+#define CEPH_RASIZE_DEFAULT (8192*1024) /* max readahead */
#define CEPH_MAX_READDIR_DEFAULT 1024
#define CEPH_MAX_READDIR_BYTES_DEFAULT (512*1024)
#define CEPH_SNAPDIRNAME_DEFAULT ".snap"
--
1.8.3.1
next prev parent reply other threads:[~2017-01-10 13:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <7C9D4085-7D14-4BFB-B675-8FE3C661B1C3@redhat.com>
2017-01-10 12:56 ` [PATCH v3] ceph: set io_pages bdi hint Andreas Gerstmayr
2017-01-10 13:17 ` Andreas Gerstmayr [this message]
2017-01-10 16:26 ` [PATCH v4] " Jeff Layton
2017-01-11 2:43 ` Yan, Zheng
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