[PATCH net-next v6 0/5] remove page frag implementation in vhost_net

[PATCH net-next v6 0/5] remove page frag implementation in vhost_net

[Yunsheng Lin]

Currently there are three implementations for page frag:

1. mm/page_alloc.c: net stack seems to be using it in the
   rx part with 'struct page_frag_cache' and the main API
   being page_frag_alloc_align().
2. net/core/sock.c: net stack seems to be using it in the
   tx part with 'struct page_frag' and the main API being
   skb_page_frag_refill().
3. drivers/vhost/net.c: vhost seems to be using it to build
   xdp frame, and it's implementation seems to be a mix of
   the above two.

This patchset tries to unfiy the page frag implementation a
little bit by unifying gfp bit for order 3 page allocation
and replacing page frag implementation in vhost.c with the
one in page_alloc.c.

After this patchset, we are not only able to unify the page
frag implementation a little, but also able to have about
0.5% performance boost testing by using the vhost_net_test
introduced in the last patch.

Before this patchset:
Performance counter stats for './vhost_net_test' (10 runs):

     305325.78 msec task-clock                       #    1.738 CPUs utilized               ( +-  0.12% )
       1048668      context-switches                 #    3.435 K/sec                       ( +-  0.00% )
            11      cpu-migrations                   #    0.036 /sec                        ( +- 17.64% )
            33      page-faults                      #    0.108 /sec                        ( +-  0.49% )
  244651819491      cycles                           #    0.801 GHz                         ( +-  0.43% )  (64)
   64714638024      stalled-cycles-frontend          #   26.45% frontend cycles idle        ( +-  2.19% )  (67)
   30774313491      stalled-cycles-backend           #   12.58% backend cycles idle         ( +-  7.68% )  (70)
  201749748680      instructions                     #    0.82  insn per cycle
                                              #    0.32  stalled cycles per insn     ( +-  0.41% )  (66.76%)
   65494787909      branches                         #  214.508 M/sec                       ( +-  0.35% )  (64)
    4284111313      branch-misses                    #    6.54% of all branches             ( +-  0.45% )  (66)

       175.699 +- 0.189 seconds time elapsed  ( +-  0.11% )


After this patchset:
Performance counter stats for './vhost_net_test' (10 runs):

     303974.38 msec task-clock                       #    1.739 CPUs utilized               ( +-  0.14% )
       1048807      context-switches                 #    3.450 K/sec                       ( +-  0.00% )
            14      cpu-migrations                   #    0.046 /sec                        ( +- 12.86% )
            33      page-faults                      #    0.109 /sec                        ( +-  0.46% )
  251289376347      cycles                           #    0.827 GHz                         ( +-  0.32% )  (60)
   67885175415      stalled-cycles-frontend          #   27.01% frontend cycles idle        ( +-  0.48% )  (63)
   27809282600      stalled-cycles-backend           #   11.07% backend cycles idle         ( +-  0.36% )  (71)
  195543234672      instructions                     #    0.78  insn per cycle
                                              #    0.35  stalled cycles per insn     ( +-  0.29% )  (69.04%)
   62423183552      branches                         #  205.357 M/sec                       ( +-  0.48% )  (67)
    4135666632      branch-misses                    #    6.63% of all branches             ( +-  0.63% )  (67)

       174.764 +- 0.214 seconds time elapsed  ( +-  0.12% )

Changelog:
V6: Add timeout for poll() and simplify some logic as suggested
    by Jason.

V5: Address the comment from jason in vhost_net_test.c and the
    comment about leaving out the gfp change for page frag in
    sock.c as suggested by Paolo.

V4: Resend based on latest net-next branch.

V3:
1. Add __page_frag_alloc_align() which is passed with the align mask
   the original function expected as suggested by Alexander.
2. Drop patch 3 in v2 suggested by Alexander.
3. Reorder patch 4 & 5 in v2 suggested by Alexander.

Note that placing this gfp flags handing for order 3 page in an inline
function is not considered, as we may be able to unify the page_frag
and page_frag_cache handling.

V2: Change 'xor'd' to 'masked off', add vhost tx testing for
    vhost_net_test.

V1: Fix some typo, drop RFC tag and rebase on latest net-next.

Yunsheng Lin (5):
  mm/page_alloc: modify page_frag_alloc_align() to accept align as an
    argument
  page_frag: unify gfp bits for order 3 page allocation
  net: introduce page_frag_cache_drain()
  vhost/net: remove vhost_net_page_frag_refill()
  tools: virtio: introduce vhost_net_test

 drivers/net/ethernet/google/gve/gve_main.c |  11 +-
 drivers/net/ethernet/mediatek/mtk_wed_wo.c |  17 +-
 drivers/nvme/host/tcp.c                    |   7 +-
 drivers/nvme/target/tcp.c                  |   4 +-
 drivers/vhost/net.c                        |  91 ++--
 include/linux/gfp.h                        |  16 +-
 mm/page_alloc.c                            |  22 +-
 net/core/skbuff.c                          |   9 +-
 tools/virtio/.gitignore                    |   1 +
 tools/virtio/Makefile                      |   8 +-
 tools/virtio/linux/virtio_config.h         |   4 +
 tools/virtio/vhost_net_test.c              | 532 +++++++++++++++++++++
 12 files changed, 609 insertions(+), 113 deletions(-)
 create mode 100644 tools/virtio/vhost_net_test.c

-- 
2.33.0

[PATCH net-next v6 4/5] vhost/net: remove vhost_net_page_frag_refill()

[Yunsheng Lin]

The page frag in vhost_net_page_frag_refill() uses the
'struct page_frag' from skb_page_frag_refill(), but it's
implementation is similar to page_frag_alloc_align() now.

This patch removes vhost_net_page_frag_refill() by using
'struct page_frag_cache' instead of 'struct page_frag',
and allocating frag using page_frag_alloc_align().

The added benefit is that not only unifying the page frag
implementation a little, but also having about 0.5% performance
boost testing by using the vhost_net_test introduced in the
last patch.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/net.c | 91 ++++++++++++++-------------------------------
 1 file changed, 27 insertions(+), 64 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e574e21cc0ca..4b2fcb228a0a 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -141,10 +141,8 @@ struct vhost_net {
 	unsigned tx_zcopy_err;
 	/* Flush in progress. Protected by tx vq lock. */
 	bool tx_flush;
-	/* Private page frag */
-	struct page_frag page_frag;
-	/* Refcount bias of page frag */
-	int refcnt_bias;
+	/* Private page frag cache */
+	struct page_frag_cache pf_cache;
 };
 
 static unsigned vhost_net_zcopy_mask __read_mostly;
@@ -655,41 +653,6 @@ static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len)
 	       !vhost_vq_avail_empty(vq->dev, vq);
 }
 
-static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz,
-				       struct page_frag *pfrag, gfp_t gfp)
-{
-	if (pfrag->page) {
-		if (pfrag->offset + sz <= pfrag->size)
-			return true;
-		__page_frag_cache_drain(pfrag->page, net->refcnt_bias);
-	}
-
-	pfrag->offset = 0;
-	net->refcnt_bias = 0;
-	if (SKB_FRAG_PAGE_ORDER) {
-		/* Avoid direct reclaim but allow kswapd to wake */
-		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
-					  __GFP_COMP | __GFP_NOWARN |
-					  __GFP_NORETRY | __GFP_NOMEMALLOC,
-					  SKB_FRAG_PAGE_ORDER);
-		if (likely(pfrag->page)) {
-			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
-			goto done;
-		}
-	}
-	pfrag->page = alloc_page(gfp);
-	if (likely(pfrag->page)) {
-		pfrag->size = PAGE_SIZE;
-		goto done;
-	}
-	return false;
-
-done:
-	net->refcnt_bias = USHRT_MAX;
-	page_ref_add(pfrag->page, USHRT_MAX - 1);
-	return true;
-}
-
 #define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
 
 static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
@@ -699,7 +662,6 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
 	struct vhost_net *net = container_of(vq->dev, struct vhost_net,
 					     dev);
 	struct socket *sock = vhost_vq_get_backend(vq);
-	struct page_frag *alloc_frag = &net->page_frag;
 	struct virtio_net_hdr *gso;
 	struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
 	struct tun_xdp_hdr *hdr;
@@ -710,6 +672,7 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
 	int sock_hlen = nvq->sock_hlen;
 	void *buf;
 	int copied;
+	int ret;
 
 	if (unlikely(len < nvq->sock_hlen))
 		return -EFAULT;
@@ -719,18 +682,17 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
 		return -ENOSPC;
 
 	buflen += SKB_DATA_ALIGN(len + pad);
-	alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
-	if (unlikely(!vhost_net_page_frag_refill(net, buflen,
-						 alloc_frag, GFP_KERNEL)))
+	buf = page_frag_alloc_align(&net->pf_cache, buflen, GFP_KERNEL,
+				    SMP_CACHE_BYTES);
+	if (unlikely(!buf))
 		return -ENOMEM;
 
-	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
-	copied = copy_page_from_iter(alloc_frag->page,
-				     alloc_frag->offset +
-				     offsetof(struct tun_xdp_hdr, gso),
-				     sock_hlen, from);
-	if (copied != sock_hlen)
-		return -EFAULT;
+	copied = copy_from_iter(buf + offsetof(struct tun_xdp_hdr, gso),
+				sock_hlen, from);
+	if (copied != sock_hlen) {
+		ret = -EFAULT;
+		goto err;
+	}
 
 	hdr = buf;
 	gso = &hdr->gso;
@@ -743,27 +705,30 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
 			       vhost16_to_cpu(vq, gso->csum_start) +
 			       vhost16_to_cpu(vq, gso->csum_offset) + 2);
 
-		if (vhost16_to_cpu(vq, gso->hdr_len) > len)
-			return -EINVAL;
+		if (vhost16_to_cpu(vq, gso->hdr_len) > len) {
+			ret = -EINVAL;
+			goto err;
+		}
 	}
 
 	len -= sock_hlen;
-	copied = copy_page_from_iter(alloc_frag->page,
-				     alloc_frag->offset + pad,
-				     len, from);
-	if (copied != len)
-		return -EFAULT;
+	copied = copy_from_iter(buf + pad, len, from);
+	if (copied != len) {
+		ret = -EFAULT;
+		goto err;
+	}
 
 	xdp_init_buff(xdp, buflen, NULL);
 	xdp_prepare_buff(xdp, buf, pad, len, true);
 	hdr->buflen = buflen;
 
-	--net->refcnt_bias;
-	alloc_frag->offset += buflen;
-
 	++nvq->batched_xdp;
 
 	return 0;
+
+err:
+	page_frag_free(buf);
+	return ret;
 }
 
 static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
@@ -1353,8 +1318,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 			vqs[VHOST_NET_VQ_RX]);
 
 	f->private_data = n;
-	n->page_frag.page = NULL;
-	n->refcnt_bias = 0;
+	n->pf_cache.va = NULL;
 
 	return 0;
 }
@@ -1422,8 +1386,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
 	kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
 	kfree(n->vqs[VHOST_NET_VQ_TX].xdp);
 	kfree(n->dev.vqs);
-	if (n->page_frag.page)
-		__page_frag_cache_drain(n->page_frag.page, n->refcnt_bias);
+	page_frag_cache_drain(&n->pf_cache);
 	kvfree(n);
 	return 0;
 }
-- 
2.33.0

Re: [PATCH net-next v6 0/5] remove page frag implementation in vhost_net

[Michael S. Tsirkin]

On Wed, Feb 28, 2024 at 05:30:07PM +0800, Yunsheng Lin wrote:
> Currently there are three implementations for page frag:
> 
> 1. mm/page_alloc.c: net stack seems to be using it in the
>    rx part with 'struct page_frag_cache' and the main API
>    being page_frag_alloc_align().
> 2. net/core/sock.c: net stack seems to be using it in the
>    tx part with 'struct page_frag' and the main API being
>    skb_page_frag_refill().
> 3. drivers/vhost/net.c: vhost seems to be using it to build
>    xdp frame, and it's implementation seems to be a mix of
>    the above two.
> 
> This patchset tries to unfiy the page frag implementation a
> little bit by unifying gfp bit for order 3 page allocation
> and replacing page frag implementation in vhost.c with the
> one in page_alloc.c.

Looks good

Acked-by: Michael S. Tsirkin <mst@redhat.com>



> After this patchset, we are not only able to unify the page
> frag implementation a little, but also able to have about
> 0.5% performance boost testing by using the vhost_net_test
> introduced in the last patch.
> 
> Before this patchset:
> Performance counter stats for './vhost_net_test' (10 runs):
> 
>      305325.78 msec task-clock                       #    1.738 CPUs utilized               ( +-  0.12% )
>        1048668      context-switches                 #    3.435 K/sec                       ( +-  0.00% )
>             11      cpu-migrations                   #    0.036 /sec                        ( +- 17.64% )
>             33      page-faults                      #    0.108 /sec                        ( +-  0.49% )
>   244651819491      cycles                           #    0.801 GHz                         ( +-  0.43% )  (64)
>    64714638024      stalled-cycles-frontend          #   26.45% frontend cycles idle        ( +-  2.19% )  (67)
>    30774313491      stalled-cycles-backend           #   12.58% backend cycles idle         ( +-  7.68% )  (70)
>   201749748680      instructions                     #    0.82  insn per cycle
>                                               #    0.32  stalled cycles per insn     ( +-  0.41% )  (66.76%)
>    65494787909      branches                         #  214.508 M/sec                       ( +-  0.35% )  (64)
>     4284111313      branch-misses                    #    6.54% of all branches             ( +-  0.45% )  (66)
> 
>        175.699 +- 0.189 seconds time elapsed  ( +-  0.11% )
> 
> 
> After this patchset:
> Performance counter stats for './vhost_net_test' (10 runs):
> 
>      303974.38 msec task-clock                       #    1.739 CPUs utilized               ( +-  0.14% )
>        1048807      context-switches                 #    3.450 K/sec                       ( +-  0.00% )
>             14      cpu-migrations                   #    0.046 /sec                        ( +- 12.86% )
>             33      page-faults                      #    0.109 /sec                        ( +-  0.46% )
>   251289376347      cycles                           #    0.827 GHz                         ( +-  0.32% )  (60)
>    67885175415      stalled-cycles-frontend          #   27.01% frontend cycles idle        ( +-  0.48% )  (63)
>    27809282600      stalled-cycles-backend           #   11.07% backend cycles idle         ( +-  0.36% )  (71)
>   195543234672      instructions                     #    0.78  insn per cycle
>                                               #    0.35  stalled cycles per insn     ( +-  0.29% )  (69.04%)
>    62423183552      branches                         #  205.357 M/sec                       ( +-  0.48% )  (67)
>     4135666632      branch-misses                    #    6.63% of all branches             ( +-  0.63% )  (67)
> 
>        174.764 +- 0.214 seconds time elapsed  ( +-  0.12% )
> 
> Changelog:
> V6: Add timeout for poll() and simplify some logic as suggested
>     by Jason.
> 
> V5: Address the comment from jason in vhost_net_test.c and the
>     comment about leaving out the gfp change for page frag in
>     sock.c as suggested by Paolo.
> 
> V4: Resend based on latest net-next branch.
> 
> V3:
> 1. Add __page_frag_alloc_align() which is passed with the align mask
>    the original function expected as suggested by Alexander.
> 2. Drop patch 3 in v2 suggested by Alexander.
> 3. Reorder patch 4 & 5 in v2 suggested by Alexander.
> 
> Note that placing this gfp flags handing for order 3 page in an inline
> function is not considered, as we may be able to unify the page_frag
> and page_frag_cache handling.
> 
> V2: Change 'xor'd' to 'masked off', add vhost tx testing for
>     vhost_net_test.
> 
> V1: Fix some typo, drop RFC tag and rebase on latest net-next.
> 
> Yunsheng Lin (5):
>   mm/page_alloc: modify page_frag_alloc_align() to accept align as an
>     argument
>   page_frag: unify gfp bits for order 3 page allocation
>   net: introduce page_frag_cache_drain()
>   vhost/net: remove vhost_net_page_frag_refill()
>   tools: virtio: introduce vhost_net_test
> 
>  drivers/net/ethernet/google/gve/gve_main.c |  11 +-
>  drivers/net/ethernet/mediatek/mtk_wed_wo.c |  17 +-
>  drivers/nvme/host/tcp.c                    |   7 +-
>  drivers/nvme/target/tcp.c                  |   4 +-
>  drivers/vhost/net.c                        |  91 ++--
>  include/linux/gfp.h                        |  16 +-
>  mm/page_alloc.c                            |  22 +-
>  net/core/skbuff.c                          |   9 +-
>  tools/virtio/.gitignore                    |   1 +
>  tools/virtio/Makefile                      |   8 +-
>  tools/virtio/linux/virtio_config.h         |   4 +
>  tools/virtio/vhost_net_test.c              | 532 +++++++++++++++++++++
>  12 files changed, 609 insertions(+), 113 deletions(-)
>  create mode 100644 tools/virtio/vhost_net_test.c
> 
> -- 
> 2.33.0
> 

Re: [PATCH net-next v6 0/5] remove page frag implementation in vhost_net

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Wed, 28 Feb 2024 17:30:07 +0800 you wrote:
> Currently there are three implementations for page frag:
> 
> 1. mm/page_alloc.c: net stack seems to be using it in the
>    rx part with 'struct page_frag_cache' and the main API
>    being page_frag_alloc_align().
> 2. net/core/sock.c: net stack seems to be using it in the
>    tx part with 'struct page_frag' and the main API being
>    skb_page_frag_refill().
> 3. drivers/vhost/net.c: vhost seems to be using it to build
>    xdp frame, and it's implementation seems to be a mix of
>    the above two.
> 
> [...]

Here is the summary with links:
  - [net-next,v6,1/5] mm/page_alloc: modify page_frag_alloc_align() to accept align as an argument
    https://git.kernel.org/netdev/net-next/c/411c5f36805c
  - [net-next,v6,2/5] page_frag: unify gfp bits for order 3 page allocation
    https://git.kernel.org/netdev/net-next/c/4bc0d63a2395
  - [net-next,v6,3/5] net: introduce page_frag_cache_drain()
    https://git.kernel.org/netdev/net-next/c/a0727489ac22
  - [net-next,v6,4/5] vhost/net: remove vhost_net_page_frag_refill()
    https://git.kernel.org/netdev/net-next/c/4051bd8129ac
  - [net-next,v6,5/5] tools: virtio: introduce vhost_net_test
    https://git.kernel.org/netdev/net-next/c/c5d3705cfd93

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH net-next v6 0/5] remove page frag implementation in vhost_net

[Michael S. Tsirkin]

On Wed, Feb 28, 2024 at 05:30:07PM +0800, Yunsheng Lin wrote:
> Currently there are three implementations for page frag:
> 
> 1. mm/page_alloc.c: net stack seems to be using it in the
>    rx part with 'struct page_frag_cache' and the main API
>    being page_frag_alloc_align().
> 2. net/core/sock.c: net stack seems to be using it in the
>    tx part with 'struct page_frag' and the main API being
>    skb_page_frag_refill().
> 3. drivers/vhost/net.c: vhost seems to be using it to build
>    xdp frame, and it's implementation seems to be a mix of
>    the above two.
> 
> This patchset tries to unfiy the page frag implementation a
> little bit by unifying gfp bit for order 3 page allocation
> and replacing page frag implementation in vhost.c with the
> one in page_alloc.c.
> 
> After this patchset, we are not only able to unify the page
> frag implementation a little, but also able to have about
> 0.5% performance boost testing by using the vhost_net_test
> introduced in the last patch.
> 
> Before this patchset:
> Performance counter stats for './vhost_net_test' (10 runs):
> 
>      305325.78 msec task-clock                       #    1.738 CPUs utilized               ( +-  0.12% )
>        1048668      context-switches                 #    3.435 K/sec                       ( +-  0.00% )
>             11      cpu-migrations                   #    0.036 /sec                        ( +- 17.64% )
>             33      page-faults                      #    0.108 /sec                        ( +-  0.49% )
>   244651819491      cycles                           #    0.801 GHz                         ( +-  0.43% )  (64)
>    64714638024      stalled-cycles-frontend          #   26.45% frontend cycles idle        ( +-  2.19% )  (67)
>    30774313491      stalled-cycles-backend           #   12.58% backend cycles idle         ( +-  7.68% )  (70)
>   201749748680      instructions                     #    0.82  insn per cycle
>                                               #    0.32  stalled cycles per insn     ( +-  0.41% )  (66.76%)
>    65494787909      branches                         #  214.508 M/sec                       ( +-  0.35% )  (64)
>     4284111313      branch-misses                    #    6.54% of all branches             ( +-  0.45% )  (66)
> 
>        175.699 +- 0.189 seconds time elapsed  ( +-  0.11% )
> 
> 
> After this patchset:
> Performance counter stats for './vhost_net_test' (10 runs):
> 
>      303974.38 msec task-clock                       #    1.739 CPUs utilized               ( +-  0.14% )
>        1048807      context-switches                 #    3.450 K/sec                       ( +-  0.00% )
>             14      cpu-migrations                   #    0.046 /sec                        ( +- 12.86% )
>             33      page-faults                      #    0.109 /sec                        ( +-  0.46% )
>   251289376347      cycles                           #    0.827 GHz                         ( +-  0.32% )  (60)
>    67885175415      stalled-cycles-frontend          #   27.01% frontend cycles idle        ( +-  0.48% )  (63)
>    27809282600      stalled-cycles-backend           #   11.07% backend cycles idle         ( +-  0.36% )  (71)
>   195543234672      instructions                     #    0.78  insn per cycle
>                                               #    0.35  stalled cycles per insn     ( +-  0.29% )  (69.04%)
>    62423183552      branches                         #  205.357 M/sec                       ( +-  0.48% )  (67)
>     4135666632      branch-misses                    #    6.63% of all branches             ( +-  0.63% )  (67)
> 
>        174.764 +- 0.214 seconds time elapsed  ( +-  0.12% )

The perf diff is in the noise, but the cleanup is nice.
Thanks!

Acked-by: Michael S. Tsirkin <mst@redhat.com>



> Changelog:
> V6: Add timeout for poll() and simplify some logic as suggested
>     by Jason.
> 
> V5: Address the comment from jason in vhost_net_test.c and the
>     comment about leaving out the gfp change for page frag in
>     sock.c as suggested by Paolo.
> 
> V4: Resend based on latest net-next branch.
> 
> V3:
> 1. Add __page_frag_alloc_align() which is passed with the align mask
>    the original function expected as suggested by Alexander.
> 2. Drop patch 3 in v2 suggested by Alexander.
> 3. Reorder patch 4 & 5 in v2 suggested by Alexander.
> 
> Note that placing this gfp flags handing for order 3 page in an inline
> function is not considered, as we may be able to unify the page_frag
> and page_frag_cache handling.
> 
> V2: Change 'xor'd' to 'masked off', add vhost tx testing for
>     vhost_net_test.
> 
> V1: Fix some typo, drop RFC tag and rebase on latest net-next.
> 
> Yunsheng Lin (5):
>   mm/page_alloc: modify page_frag_alloc_align() to accept align as an
>     argument
>   page_frag: unify gfp bits for order 3 page allocation
>   net: introduce page_frag_cache_drain()
>   vhost/net: remove vhost_net_page_frag_refill()
>   tools: virtio: introduce vhost_net_test
> 
>  drivers/net/ethernet/google/gve/gve_main.c |  11 +-
>  drivers/net/ethernet/mediatek/mtk_wed_wo.c |  17 +-
>  drivers/nvme/host/tcp.c                    |   7 +-
>  drivers/nvme/target/tcp.c                  |   4 +-
>  drivers/vhost/net.c                        |  91 ++--
>  include/linux/gfp.h                        |  16 +-
>  mm/page_alloc.c                            |  22 +-
>  net/core/skbuff.c                          |   9 +-
>  tools/virtio/.gitignore                    |   1 +
>  tools/virtio/Makefile                      |   8 +-
>  tools/virtio/linux/virtio_config.h         |   4 +
>  tools/virtio/vhost_net_test.c              | 532 +++++++++++++++++++++
>  12 files changed, 609 insertions(+), 113 deletions(-)
>  create mode 100644 tools/virtio/vhost_net_test.c
> 
> -- 
> 2.33.0
>