netdev - Re: [PATCH 2/4] [RFC] virtio: Introduce new API to get free space

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110504195818.GA20255@redhat.com>
Date:	Wed, 4 May 2011 22:58:18 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Krishna Kumar <krkumar2@...ibm.com>
Cc:	davem@...emloft.net, eric.dumazet@...il.com, kvm@...r.kernel.org,
	netdev@...r.kernel.org, rusty@...tcorp.com.au, mashirle@...ibm.com
Subject: Re: [PATCH 2/4] [RFC] virtio: Introduce new API to get free space

On Wed, May 04, 2011 at 07:33:19PM +0530, Krishna Kumar wrote:
> @@ -185,11 +193,6 @@ int virtqueue_add_buf_gfp(struct virtque
>  	if (vq->num_free < out + in) {
>  		pr_debug("Can't add buf len %i - avail = %i\n",
>  			 out + in, vq->num_free);
> -		/* FIXME: for historical reasons, we force a notify here if
> -		 * there are outgoing parts to the buffer.  Presumably the
> -		 * host should service the ring ASAP. */
> -		if (out)
> -			vq->notify(&vq->vq);
>  		END_USE(vq);
>  		return -ENOSPC;
>  	}

I thought about it some more.  We should typically not get into this
state with the current driver as we check capacity upfront.

So why would this change help performance?
Shirley, any idea?

-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html