Re: [PATCH] ceph: enable async dirops by default

[Ilya Dryomov <idryomov@gmail.com>]

On Tue, Jan 19, 2021 at 4:06 PM Jeff Layton <jlayton@kernel.org> wrote:
>
> This has been behaving reasonably well in testing, and enabling this
> offers significant performance benefits. Enable async dirops by default
> in the kclient going forward, and change show_options to add "wsync"
> when they are disabled.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/ceph/super.c | 4 ++--
>  fs/ceph/super.h | 5 +++--
>  2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index 9b1b7f4cfdd4..884e2ffabfaf 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -577,8 +577,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
>         if (fsopt->flags & CEPH_MOUNT_OPT_CLEANRECOVER)
>                 seq_show_option(m, "recover_session", "clean");
>
> -       if (fsopt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS)
> -               seq_puts(m, ",nowsync");
> +       if (!(fsopt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS))
> +               seq_puts(m, ",wsync");
>
>         if (fsopt->wsize != CEPH_MAX_WRITE_SIZE)
>                 seq_printf(m, ",wsize=%u", fsopt->wsize);
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 13b02887b085..8ee2745f6257 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -46,8 +46,9 @@
>  #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */
>
>  #define CEPH_MOUNT_OPT_DEFAULT                 \
> -       (CEPH_MOUNT_OPT_DCACHE |                \
> -        CEPH_MOUNT_OPT_NOCOPYFROM)
> +       (CEPH_MOUNT_OPT_DCACHE          |       \
> +        CEPH_MOUNT_OPT_NOCOPYFROM      |       \
> +        CEPH_MOUNT_OPT_ASYNC_DIROPS)
>
>  #define ceph_set_mount_opt(fsc, opt) \
>         (fsc)->mount_options->flags |= CEPH_MOUNT_OPT_##opt
> --
> 2.29.2
>

Hi Jeff,

Is it being tested by teuthology?   I see commit 4181742a3ba8 ("qa:
allow arbitrary mount options on kclient mounts"), but nothing beyond
that.  I think "nowsync" needs to be turned on and get at least some
nightly coverage before the default is flipped.

Thanks,

                Ilya