From: Song Liu <song@kernel.org>
To: Alexander Aring <aahringo@redhat.com>
Cc: Heming Zhao <heming.zhao@suse.com>,
yukuai3@huawei.com, teigland@redhat.com, gfs2@lists.linux.dev,
linux-raid@vger.kernel.org
Subject: Re: [PATCH dlm/next 8/8] md-cluster: use DLM_LSFL_SOFTIRQ for dlm_new_lockspace()
Date: Fri, 7 Jun 2024 21:21:34 -0700 [thread overview]
Message-ID: <CAPhsuW6pyJ8rQ5BHG_ocJaR+ARbZwFZZm+e7bBRgTagvddr5Jg@mail.gmail.com> (raw)
In-Reply-To: <CAK-6q+j0rbQ2CZ9y9wxZBUxsgGV03nF+ahVZPJEQPoUW-Mc8nQ@mail.gmail.com>
On Thu, Jun 6, 2024 at 7:34 AM Alexander Aring <aahringo@redhat.com> wrote:
>
> Hi Heming,
>
> On Wed, Jun 5, 2024 at 10:48 PM Heming Zhao <heming.zhao@suse.com> wrote:
> >
> > On 6/6/24 02:54, Alexander Aring wrote:
> > > Hi,
> > >
> > > On Mon, Jun 3, 2024 at 5:56 PM Alexander Aring <aahringo@redhat.com> wrote:
> > >>
> > >> Recently the DLM subsystem introduced the flag DLM_LSFL_SOFTIRQ for
> > >> dlm_new_lockspace() to signal the capability to handle DLM ast/bast
> > >> callbacks in softirq context to avoid an additional context switch due
> > >> the DLM callback workqueue.
> > >>
> > >> The md-cluster implementation only does synchronized calls above the
> > >> async DLM API. That synchronized API should may be also offered by DLM,
> > >> however it is very simple as md-cluster callbacks only does a complete()
> > >> call for their wait_for_completion() wait that is occurred after the
> > >> async DLM API call. This patch activates the recently introduced
> > >> DLM_LSFL_SOFTIRQ flag that allows that the DLM callbacks are executed in
> > >> a softirq context that md-cluster can handle. It is reducing a
> > >> unnecessary context workqueue switch and should speed up DLM in some
> > >> circumstance.
> > >>
> > >
> > > Can somebody with a md-cluster environment test it as well? All I was
> > > doing was (with a working dlm_controld cluster env):
> > >
> > > mdadm --create /dev/md0 --bitmap=clustered --metadata=1.2
> > > --raid-devices=2 --level=mirror /dev/sda /dev/sdb
> > >
> > > sda and sdb are shared block devices on each node.
> > >
> > > Create a /etc/mdadm.conf with the content mostly out of:
> > >
> > > mdadm --detail --scan
> > >
> > > on each node.
> > >
> > > Then call mdadm --assemble on all nodes where not "mdadm --create ..." happened.
> > > I hope that is the right thing to do and I had with "dlm_tool ls" a
> > > UUID as a lockspace name with some md-cluster locks being around.
> >
> > The above setup method is correct.
> > SUSE doc [1] provides more details on assembling the clustered array.
> >
>
> yea, I saw that and mostly cut it down into the necessary steps in my
> development setup.
>
> Thanks for confirming I did something right here.
>
> > [1]: https://documentation.suse.com/fr-fr/sle-ha/15-SP5/html/SLE-HA-all/cha-ha-cluster-md.html#sec-ha-cluster-md-create
> >
> > >
> > > To bring this new flag upstream, would it be okay to get this through
> > > dlm-tree? I am requesting here for an "Acked-by" tag from the md
> > > maintainers.
> > >
> >
> > I compiled & tested the dlm-tree [2] with SUSE CI env, and didn't see these
> > patches introduce new issue.
> >
>
> Thanks for doing that. So that means you tried the dlm-tree with this
> patch series applied?
>
> Song or Yu, can I get an "Acked-by" from you and an answer if it is
> okay that this md-cluster.c patch goes upstream via dlm-tree?
LGTM.
Acked-by: Song Liu <song@kernel.org>
Yes, let's route this via dlm-tree.
Thanks,
Song
prev parent reply other threads:[~2024-06-08 4:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-03 21:55 [PATCH dlm/next 0/8] dlm: md: introduce DLM_LSFL_SOFTIRQ_SAFE Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 1/8] dlm: using rcu to avoid rsb lookup again Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 2/8] dlm: remove struct field with the same meaning Alexander Aring
2024-06-10 14:17 ` Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 3/8] dlm: use is_master() on checks if we are the master Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 4/8] dlm: use LSFL_FS to check if it's a kernel lockspace Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 5/8] dlm: introduce DLM_LSFL_SOFTIRQ_SAFE Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 6/8] dlm: implement LSFL_SOFTIRQ_SAFE Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 7/8] dlm: convert ls_cb_lock to rwlock Alexander Aring
2024-06-03 21:55 ` [PATCH dlm/next 8/8] md-cluster: use DLM_LSFL_SOFTIRQ for dlm_new_lockspace() Alexander Aring
2024-06-05 18:54 ` Alexander Aring
2024-06-06 2:48 ` Heming Zhao
2024-06-06 14:33 ` Alexander Aring
2024-06-06 22:55 ` Heming Zhao
2024-06-08 4:21 ` Song Liu [this message]
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