linux-api.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: thuth@linux.vnet.ibm.com, rusty@au1.ibm.com,
	linux-api@vger.kernel.org, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	David Hildenbrand <dahi@linux.vnet.ibm.com>,
	pbonzini@redhat.com, David Miller <davem@davemloft.net>
Subject: Re: [PATCH v7 16/46] virtio_blk: v1.0 support
Date: Mon, 1 Dec 2014 13:46:45 +0200	[thread overview]
Message-ID: <20141201114645.GA17505@redhat.com> (raw)
In-Reply-To: <20141201123315.1b95d06f.cornelia.huck@de.ibm.com>

On Mon, Dec 01, 2014 at 12:33:15PM +0100, Cornelia Huck wrote:
> On Mon, 1 Dec 2014 11:26:58 +0200
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > For some places on data path, it might be worth it
> > to cache the correct value e.g. as part of device
> > structure. This replaces a branch with a memory load,
> > so the gain would have to be measured, best done
> > separately?
> 
> I think we'll want to do some measuring once the basic structure is
> in place anyway.

What's meant by in place here?

> We should make sure that e.g. s390 only takes minor
> hit due to all that swapping that is needed for standard-compliant
> devices. Caching the value might certainly help in some paths.

Well, this is queued in linux-next for 3.19, so
now's the time to do it :)

  reply	other threads:[~2014-12-01 11:46 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1417359787-10138-1-git-send-email-mst@redhat.com>
2014-11-30 15:09 ` [PATCH v7 07/46] virtio: add virtio 1.0 feature bit Michael S. Tsirkin
2014-11-30 15:09 ` [PATCH v7 08/46] virtio: memory access APIs Michael S. Tsirkin
2014-12-01  9:56   ` Cornelia Huck
2014-11-30 15:10 ` [PATCH v7 12/46] virtio: set FEATURES_OK Michael S. Tsirkin
     [not found]   ` <1417359787-10138-13-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-12-01 10:11     ` Cornelia Huck
2014-11-30 15:10 ` [PATCH v7 15/46] virtio_net: v1.0 endianness Michael S. Tsirkin
2014-11-30 15:10 ` [PATCH v7 16/46] virtio_blk: v1.0 support Michael S. Tsirkin
2014-12-01  8:16   ` David Hildenbrand
2014-12-01  9:26     ` Michael S. Tsirkin
2014-12-01 11:33       ` Cornelia Huck
2014-12-01 11:46         ` Michael S. Tsirkin [this message]
2014-12-01 12:02           ` Cornelia Huck
2014-12-01 12:19             ` Michael S. Tsirkin
2014-12-01 12:34             ` Michael S. Tsirkin
     [not found]               ` <20141201123455.GA17958-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-12-01 12:40                 ` Cornelia Huck
2014-12-01 12:51                   ` Michael S. Tsirkin
2014-12-01 13:00                     ` Cornelia Huck
2014-12-01 13:47                       ` Michael S. Tsirkin
     [not found]                         ` <20141201134719.GA18305-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-12-01 14:19                           ` Cornelia Huck
2014-12-01  9:28     ` Michael S. Tsirkin
     [not found]       ` <20141201092850.GD15607-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-12-01 10:01         ` David Hildenbrand
2014-12-01 11:28           ` Cornelia Huck
2014-11-30 15:12 ` [PATCH v7 37/46] tun: move internal flag defines out of uapi Michael S. Tsirkin
2014-11-30 15:12 ` [PATCH v7 39/46] tun: add VNET_LE flag Michael S. Tsirkin
2014-11-30 15:12 ` [PATCH v7 44/46] virtio_scsi: export to userspace Michael S. Tsirkin
     [not found]   ` <1417359787-10138-45-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-30 21:43     ` Prabhakar Lad

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20141201114645.GA17505@redhat.com \
    --to=mst@redhat.com \
    --cc=cornelia.huck@de.ibm.com \
    --cc=dahi@linux.vnet.ibm.com \
    --cc=davem@davemloft.net \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=rusty@au1.ibm.com \
    --cc=thuth@linux.vnet.ibm.com \
    --cc=virtualization@lists.linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).