linux-kernel - Re: [PATCHv2-RFC 0/2] virtio: put last seen used index into ring itself

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Mon, 31 May 2010 17:16:42 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	"Michael S. Tsirkin" <mst@...hat.com>
Cc:	linux-kernel@...r.kernel.org,
	virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
	qemu-devel@...gnu.org
Subject: Re: [PATCHv2-RFC 0/2] virtio: put last seen used index into ring itself

On Thu, 27 May 2010 05:20:35 am Michael S. Tsirkin wrote:
> Here's a rewrite of the original patch with a new layout.
> I haven't tested it yet so no idea how this performs, but
> I think this addresses the cache bounce issue raised by Avi.
> Posting for early flames/comments.

Sorry, not without some evidence that it'll actually reduce cacheline
bouncing.  I *think* it will, but it's not obvious: the host may keep
looking at avail_idx as we're updating last_seen.  Or does qemu always
look at both together anyway?

Can someone convince me this is a win?
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/