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From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: peterx@redhat.com, aarcange@redhat.com,
	James.Bottomley@hansenpartnership.com, hch@infradead.org,
	davem@davemloft.net, jglisse@redhat.com, linux-mm@kvack.org,
	linux-arm-kernel@lists.infradead.org,
	linux-parisc@vger.kernel.org, christophe.de.dinechin@gmail.com,
	jrdr.linux@gmail.com
Subject: [RFC PATCH V3 1/6] vhost: generalize adding used elem
Date: Tue, 23 Apr 2019 01:54:15 -0400	[thread overview]
Message-ID: <20190423055420.26408-2-jasowang@redhat.com> (raw)
In-Reply-To: <20190423055420.26408-1-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 351af88231ad..6df76ac8200a 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2255,16 +2255,7 @@ 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;
 	}
-- 
2.18.1


WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: aarcange@redhat.com, hch@infradead.org,
	christophe.de.dinechin@gmail.com, linux-parisc@vger.kernel.org,
	peterx@redhat.com, James.Bottomley@hansenpartnership.com,
	linux-mm@kvack.org, jglisse@redhat.com, jrdr.linux@gmail.com,
	davem@davemloft.net, linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH V3 1/6] vhost: generalize adding used elem
Date: Tue, 23 Apr 2019 01:54:15 -0400	[thread overview]
Message-ID: <20190423055420.26408-2-jasowang@redhat.com> (raw)
In-Reply-To: <20190423055420.26408-1-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 351af88231ad..6df76ac8200a 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2255,16 +2255,7 @@ 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;
 	}
-- 
2.18.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-04-23  5:55 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-23  5:54 [RFC PATCH V3 0/6] vhost: accelerate metadata access Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` Jason Wang [this message]
2019-04-23  5:54   ` [RFC PATCH V3 1/6] vhost: generalize adding used elem Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` [RFC PATCH V3 2/6] vhost: fine grain userspace memory accessors Jason Wang
2019-04-23  5:54   ` Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` [RFC PATCH V3 3/6] vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch() Jason Wang
2019-04-23  5:54   ` Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` [RFC PATCH V3 4/6] vhost: introduce helpers to get the size of metadata area Jason Wang
2019-04-23  5:54   ` Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54 ` [RFC PATCH V3 5/6] vhost: factor out setting vring addr and num Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54   ` Jason Wang
2019-04-23  5:54 ` [RFC PATCH V3 6/6] vhost: access vq metadata through kernel virtual address Jason Wang
2019-04-23  5:54 ` Jason Wang
2019-04-23  5:54   ` Jason Wang
2019-05-05  9:20 ` [RFC PATCH V3 0/6] vhost: accelerate metadata access Jason Wang
2019-05-05  9:20 ` Jason Wang
2019-05-05  9:20   ` Jason Wang

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