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Date:   Sun, 5 Sep 2021 13:20:24 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Cc:     Max Gurtovoy <mgurtovoy@nvidia.com>, hch@infradead.org,
        mst@redhat.com, virtualization@lists.linux-foundation.org,
        kvm@vger.kernel.org, stefanha@redhat.com, israelr@nvidia.com,
        nitzanc@nvidia.com, oren@nvidia.com, linux-block@vger.kernel.org,
        axboe@kernel.dk
Subject: Re: [PATCH v3 1/1] virtio-blk: add num_request_queues module
 parameter
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References: <20210902204622.54354-1-mgurtovoy@nvidia.com>
 <YTR12AHOGs1nhfz1@unreal>
 <b2e60035-2e63-3162-6222-d8c862526a28@gmail.com>
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On Sun, Sep 05, 2021 at 01:49:46AM -0700, Chaitanya Kulkarni wrote:
> 
> On 9/5/2021 12:46 AM, Leon Romanovsky wrote:
> > > +static unsigned int num_request_queues;
> > > +module_param_cb(num_request_queues, &queue_count_ops, &num_request_queues,
> > > +		0644);
> > > +MODULE_PARM_DESC(num_request_queues,
> > > +		 "Number of request queues to use for blk device. Should > 0");
> > > +
> > Won't it limit all virtio block devices to the same limit?
> > 
> > It is very common to see multiple virtio-blk devices on the same system
> > and they probably need different limits.
> > 
> > Thanks
> 
> 
> Without looking into the code, that can be done adding a configfs
> 
> interface and overriding a global value (module param) when it is set from
> 
> configfs.

So why should we do double work instead of providing one working
interface from the beginning?

Thanks

> 
>