Re: [PATCH] f2fs: enable nowait async buffered writes

[Chao Yu]

On 2023/6/6 19:13, Yangtao Li wrote:
> On 2023/6/6 14:43, Chao Yu wrote:
>
> > On 2023/5/31 22:40, Yangtao Li wrote:
> > > This adds the async buffered write support to f2fs,
> > > the following is the relevant test data.
> >
> > Yangtao,
> >
> > Could you please provide detailed test command?
>
>
> Use fio to test, the following is the configuration:
>
> # io_uring
> [global]
> ioengine=io_uring
> sqthread_poll=1
> threads=1
> iodepth=32
> hipri=0
> direct=0
> fixedbufs=0
> uncached=0
> nowait=0
> force_async=0
> randrepeat=0
> time_based=0
> size=256M
> filename=/data/test/local/io_uring_test
> group_reporting
> [read256B-rand]
> bs=4096
> rw=randwrite
> numjobs=1

Thanks, it looks the performance is not very stable when iodepth is
large, e.g. 32.

Could you please add above test parameter into commit message?

Otherwise, this patch looks good to me.

Thanks,

> > Thanks,
> >
> > > iodepth      | 1    | 2    | 4    | 8    | 16   |
> > > before(M/s)  | 1012 | 1133 | 894  | 981  | 866  |
> > > after(M/s)   | 1488 | 1896 | 2081 | 2188 | 2207 |
> > >
> > > Signed-off-by: Lu Hongfei <luhongfei@xxxxxxxx>
> > > Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
> > > ---
> > >   fs/f2fs/file.c | 5 +----
> > >   1 file changed, 1 insertion(+), 4 deletions(-)
> > >
> > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > > index 23c68ee946e5..4faf2c04e325 100644
> > > --- a/fs/f2fs/file.c
> > > +++ b/fs/f2fs/file.c
> > > @@ -546,7 +546,7 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
> > >       if (err)
> > >           return err;
> > >   -    filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
> > > +    filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC;
> > >         return dquot_file_open(inode, filp);
> > >   }
> > > @@ -4515,9 +4515,6 @@ static ssize_t f2fs_buffered_write_iter(struct kiocb *iocb,
> > >       struct inode *inode = file_inode(file);
> > >       ssize_t ret;
> > >   -    if (iocb->ki_flags & IOCB_NOWAIT)
> > > -        return -EOPNOTSUPP;
> > > -
> > >       current->backing_dev_info = inode_to_bdi(inode);
> > >       ret = generic_perform_write(iocb, from);
> > >       current->backing_dev_info = NULL;