From mboxrd@z Thu Jan  1 00:00:00 1970
From: piaojun <piaojun@huawei.com>
Message-ID: <5D4A7641.9080400@huawei.com>
Date: Wed, 7 Aug 2019 14:57:05 +0800
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Subject: [Virtio-fs] [PATCH v2 0/2][RFC] virtiofsd: Improve io bandwidth by
 replacing pwrite with pwritev
List-Id: Development discussions about virtio-fs <virtio-fs.redhat.com>
List-Unsubscribe: <https://www.redhat.com/mailman/options/virtio-fs>,
	<mailto:virtio-fs-request@redhat.com?subject=unsubscribe>
List-Archive: <https://www.redhat.com/archives/virtio-fs>
List-Post: <mailto:virtio-fs@redhat.com>
List-Help: <mailto:virtio-fs-request@redhat.com?subject=help>
List-Subscribe: <https://www.redhat.com/mailman/listinfo/virtio-fs>,
	<mailto:virtio-fs-request@redhat.com?subject=subscribe>
To: virtio-fs@redhat.com

>>From my test, write bandwidth will be improved greatly by replacing
pwrite with pwritev, and the test result as below:

---
pwrite:
# fio -direct=1 -time_based -iodepth=64 -rw=randwrite -ioengine=libaio -bs=1M -size=1G -numjob=16 -runtime=30 -group_reporting -name=file -filename=/mnt/virtiofs/file
file: (g=0): rw=randwrite, bs=1M-1M/1M-1M/1M-1M, ioengine=libaio, iodepth=64
...
fio-2.13
Starting 16 processes
Jobs: 16 (f=16): [w(16)] [100.0% done] [0KB/886.0MB/0KB /s] [0/886/0 iops] [eta 00m:00s]
file: (groupid=0, jobs=16): err= 0: pid=5799: Tue Aug 6 18:48:26 2019
write: io=26881MB, bw=916988KB/s, iops=895, runt= 30018msec

pwritev:
# fio -direct=1 -time_based -iodepth=64 -rw=randwrite -ioengine=libaio -bs=1M -size=1G -numjob=16 -runtime=30 -group_reporting -name=file -filename=/mnt/virtiofs/file
file: (g=0): rw=randwrite, bs=1M-1M/1M-1M/1M-1M, ioengine=libaio, iodepth=64
...
fio-2.13
Starting 16 processes
Jobs: 16 (f=16): [w(16)] [100.0% done] [0KB/1793MB/0KB /s] [0/1793/0 iops] [eta 00m:00s]
file: (groupid=0, jobs=16): err= 0: pid=6328: Tue Aug 6 18:22:17 2019
write: io=52775MB, bw=1758.7MB/s, iops=1758, runt= 30009msec
---

This patch introduces writev and pwritev for lo_write_buf(). I tried my
best not doing harm to the origin code construct, and there will be
some *useless* branches in fuse_buf_copy_one() which are hard to judge
if they will be useful in the future. So I just leave them alone
safely. If the cleanup work is necessary, please let me know.

v2
  - Split into two patches
  - Add the lost flags support, such as FUSE_BUF_PHYS_ADDR

Jun Piao (2):
  add definition of fuse_buf_writev().
  use fuse_buf_writev to replace fuse_buf_write for better performance

Signed-off-by: Jun Piao <piaojun@huawei.com>
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 buffer.c         |   37 +++++++++++++++++++++++++++++++++++++
 fuse_common.h    |   14 ++++++++++++++
 passthrough_ll.c |    5 ++++-
 seccomp.c        |    2 +
--