On Thu, Oct 15, 2020 at 02:21:58PM -0700, Linus Torvalds wrote:

[..]

I don't know why fuse does multiple pages to begin with. Why can't it
do whatever it does just one page at a time?

Sending multiple pages in single WRITE command does seem to help a lot
with performance. I modified code to write only one page at a time
and ran a fio job with sequential writes(and random writes),
block size 64K and compared the performance on virtiofs.

NAME                    WORKLOAD                Bandwidth       IOPS
one-page-write          seqwrite-psync          58.3mb          933
multi-page-write        seqwrite-psync          265.7mb         4251

one-page-write          randwrite-psync         53.5mb          856
multi-page-write        randwrite-psync         315.5mb         5047

So with multi page writes performance seems much better for this
particular workload.

Thanks
Vivek