linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jason Wang <jasowang@redhat.com>
To: virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	jasowang@redhat.com
Cc: mst@redhat.com, kvm@vger.kernel.org
Subject: [PATCH net-next V4 1/5] vhost: generalize adding used elem
Date: Wed, 23 Jan 2019 17:55:53 +0800	[thread overview]
Message-ID: <20190123095557.30168-2-jasowang@redhat.com> (raw)
In-Reply-To: <20190123095557.30168-1-jasowang@redhat.com>

Use one generic vhost_copy_to_user() instead of two dedicated
accessor. This will simplify the conversion to fine grain
accessors. About 2% improvement of PPS were seen during vitio-user
txonly test.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/vhost.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 15a216cdd507..14fad2577df3 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2250,16 +2250,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq,
 
 	start = vq->last_used_idx & (vq->num - 1);
 	used = vq->used->ring + start;
-	if (count == 1) {
-		if (vhost_put_user(vq, heads[0].id, &used->id)) {
-			vq_err(vq, "Failed to write used id");
-			return -EFAULT;
-		}
-		if (vhost_put_user(vq, heads[0].len, &used->len)) {
-			vq_err(vq, "Failed to write used len");
-			return -EFAULT;
-		}
-	} else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) {
+	if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) {
 		vq_err(vq, "Failed to write used");
 		return -EFAULT;
 	}
-- 
2.17.1


  reply	other threads:[~2019-01-23  9:56 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-23  9:55 [PATCH net-next V4 0/5] vhost: accelerate metadata access through vmap() Jason Wang
2019-01-23  9:55 ` Jason Wang [this message]
2019-01-23  9:55 ` [PATCH net-next V4 2/5] vhost: fine grain userspace memory accessors Jason Wang
2019-01-23  9:55 ` [PATCH net-next V4 3/5] vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch() Jason Wang
2019-01-23  9:55 ` [PATCH net-next V4 4/5] vhost: introduce helpers to get the size of metadata area Jason Wang
2019-01-23  9:55 ` [PATCH net-next V4 5/5] vhost: access vq metadata through kernel virtual address Jason Wang
2019-01-23 14:08   ` Michael S. Tsirkin
2019-01-24  4:07     ` Jason Wang
2019-01-24  4:11       ` Jason Wang
2019-01-24  4:53         ` Michael S. Tsirkin
2019-01-25  2:33           ` Jason Wang
2019-01-24  4:51       ` Michael S. Tsirkin
2019-01-25  3:00       ` Michael S. Tsirkin
2019-01-25  9:16         ` Jason Wang
2019-01-25  3:03   ` Michael S. Tsirkin
2019-01-25  9:21     ` Jason Wang
2019-01-25  9:24     ` Jason Wang
2019-01-23 13:58 ` [PATCH net-next V4 0/5] vhost: accelerate metadata access through vmap() Michael S. Tsirkin
2019-01-23 17:24   ` David Miller
2019-01-26 22:37 ` David Miller
2019-01-27  0:31   ` Michael S. Tsirkin
2019-01-29  2:34     ` Jason Wang

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=20190123095557.30168-2-jasowang@redhat.com \
    --to=jasowang@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=netdev@vger.kernel.org \
    --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).