Sender: Tejun Heo <htejun@gmail.com>
Date:   Fri, 7 Jan 2022 11:25:12 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Imran Khan <imran.f.khan@oracle.com>
Cc:     Greg KH <gregkh@linuxfoundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2 1/2] kernfs: use kernfs_node specific mutex and
 spinlock.
Message-ID: <YdivuA12i3VU8zO/@slm.duckdns.org>
References: <20220103084544.1109829-1-imran.f.khan@oracle.com>
 <20220103084544.1109829-2-imran.f.khan@oracle.com>
 <YdLH6qQNxa11YmRO@kroah.com>
 <719eb5d2-680c-e596-1446-3ca8f47c3aea@oracle.com>
 <YdP57ij4JxahpdnC@kroah.com>
 <YddRVH4r6uNHt3xa@slm.duckdns.org>
 <03cb9939-efbb-1ce8-42f5-c167ac5246da@oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <03cb9939-efbb-1ce8-42f5-c167ac5246da@oracle.com>
Precedence: bulk

Hello,

On Fri, Jan 07, 2022 at 11:01:55PM +1100, Imran Khan wrote:
> Could you please suggest me some current users of hashed locks ? I can
> check that code and modify my patches accordingly.

include/linux/blockgroup_lock.h seems to be one.

> As of now I have not found any standard benchmarks/workloads to show the
> impact of this contention. We have some in house DB applications where
> the impact can be easily seen.  Of course those applications can be
> modified to get the needed data from somewhere else or access sysfs less
> frequently but nonetheless I am trying to make the current locking
> scheme more scalable.

I don't think it needs to show up in one of the common benchmarks but what
the application does should make some sense. Which files are involved in the
contentions?

Thanks.

-- 
tejun