From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org,
"jianchao.wang" <jianchao.w.wang@oracle.com>,
Guenter Roeck <linux@roeck-us.net>,
stable@vger.kernel.org
Subject: Re: [PATCH V2 for-4.21 1/2] blk-mq: not embed .mq_kobj and ctx->kobj into queue instance
Date: Mon, 19 Nov 2018 11:06:06 +0100 [thread overview]
Message-ID: <20181119100606.GB19910@kroah.com> (raw)
In-Reply-To: <20181117022637.GB8872@ming.t460p>
On Sat, Nov 17, 2018 at 10:26:38AM +0800, Ming Lei wrote:
> On Fri, Nov 16, 2018 at 06:05:21AM -0800, Greg Kroah-Hartman wrote:
> > On Fri, Nov 16, 2018 at 07:23:10PM +0800, Ming Lei wrote:
> > > @@ -456,7 +456,7 @@ struct request_queue {
> > > /*
> > > * mq queue kobject
> > > */
> > > - struct kobject mq_kobj;
> > > + struct kobject *mq_kobj;
> >
> > What is this kobject even used for? It wasn't obvious at all from this
> > patch, why is it needed if you are not using it to reference count the
> > larger structure here?
>
> All attributes and kobjects under /sys/block/$DEV/mq are covered by this kobject
> actually, and all are for exposing blk-mq specific information, but now there is
> only blk-mq, and legacy io path is removed.
I am sorry, but I really can not parse this sentance at all.
What Documentation/ABI/ entries are covered by this kobject, that should
help me out more. And what do you mean by "legacy io"?
> That is why I mentioned we may remove this kobject last time and move all under
> /sys/block/$DEV/queue, however you thought that may break some userspace.
Who relies on these sysfs files today?
> If we want to backport them to stable, this patch may be a bit easier to go.
Why do you want to backport any of this to stable?
thanks,
greg k-h
next prev parent reply other threads:[~2018-11-19 20:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20181116112311.4117-1-ming.lei@redhat.com>
2018-11-16 11:23 ` [PATCH V2 for-4.21 1/2] blk-mq: not embed .mq_kobj and ctx->kobj into queue instance Ming Lei
2018-11-16 14:05 ` Greg Kroah-Hartman
2018-11-17 2:26 ` Ming Lei
2018-11-19 10:06 ` Greg Kroah-Hartman [this message]
2018-11-19 10:20 ` Ming Lei
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