[PATCH v3 net-next 4/5] net: use the new dev_page_is_reusable() instead of private versions

[PATCH v3 net-next 4/5] net: use the new dev_page_is_reusable() instead of private versions

[Alexander Lobakin]

Now we can remove a bunch of identical functions from the drivers and
make them use common dev_page_is_reusable(). All {,un}likely() checks
are omitted since it's already present in this helper.
Also update some comments near the call sites.

Suggested-by: David Rientjes <rientjes@google.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 17 ++++++-----------
 drivers/net/ethernet/intel/fm10k/fm10k_main.c   | 13 ++++---------
 drivers/net/ethernet/intel/i40e/i40e_txrx.c     | 15 +--------------
 drivers/net/ethernet/intel/iavf/iavf_txrx.c     | 15 +--------------
 drivers/net/ethernet/intel/ice/ice_txrx.c       | 13 ++-----------
 drivers/net/ethernet/intel/igb/igb_main.c       |  9 ++-------
 drivers/net/ethernet/intel/igc/igc_main.c       |  9 ++-------
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c   |  9 ++-------
 .../net/ethernet/intel/ixgbevf/ixgbevf_main.c   |  9 ++-------
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c |  7 +------
 10 files changed, 23 insertions(+), 93 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 512080640cbc..f39f5b1c4cec 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -2800,12 +2800,6 @@ static void hns3_nic_alloc_rx_buffers(struct hns3_enet_ring *ring,
 	writel(i, ring->tqp->io_base + HNS3_RING_RX_RING_HEAD_REG);
 }
 
-static bool hns3_page_is_reusable(struct page *page)
-{
-	return page_to_nid(page) == numa_mem_id() &&
-		!page_is_pfmemalloc(page);
-}
-
 static bool hns3_can_reuse_page(struct hns3_desc_cb *cb)
 {
 	return (page_count(cb->priv) - cb->pagecnt_bias) == 1;
@@ -2823,10 +2817,11 @@ static void hns3_nic_reuse_page(struct sk_buff *skb, int i,
 	skb_add_rx_frag(skb, i, desc_cb->priv, desc_cb->page_offset + pull_len,
 			size - pull_len, truesize);
 
-	/* Avoid re-using remote pages, or the stack is still using the page
-	 * when page_offset rollback to zero, flag default unreuse
+	/* Avoid re-using remote and pfmemalloc pages, or the stack is still
+	 * using the page when page_offset rollback to zero, flag default
+	 * unreuse
 	 */
-	if (unlikely(!hns3_page_is_reusable(desc_cb->priv)) ||
+	if (!dev_page_is_reusable(desc_cb->priv) ||
 	    (!desc_cb->page_offset && !hns3_can_reuse_page(desc_cb))) {
 		__page_frag_cache_drain(desc_cb->priv, desc_cb->pagecnt_bias);
 		return;
@@ -3083,8 +3078,8 @@ static int hns3_alloc_skb(struct hns3_enet_ring *ring, unsigned int length,
 	if (length <= HNS3_RX_HEAD_SIZE) {
 		memcpy(__skb_put(skb, length), va, ALIGN(length, sizeof(long)));
 
-		/* We can reuse buffer as-is, just make sure it is local */
-		if (likely(hns3_page_is_reusable(desc_cb->priv)))
+		/* We can reuse buffer as-is, just make sure it is reusable */
+		if (dev_page_is_reusable(desc_cb->priv))
 			desc_cb->reuse_flag = 1;
 		else /* This page cannot be reused so discard it */
 			__page_frag_cache_drain(desc_cb->priv,
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index 99b8252eb969..247f44f4cb30 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -194,17 +194,12 @@ static void fm10k_reuse_rx_page(struct fm10k_ring *rx_ring,
 					 DMA_FROM_DEVICE);
 }
 
-static inline bool fm10k_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
 				    struct page *page,
 				    unsigned int __maybe_unused truesize)
 {
-	/* avoid re-using remote pages */
-	if (unlikely(fm10k_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
@@ -265,8 +260,8 @@ static bool fm10k_add_rx_frag(struct fm10k_rx_buffer *rx_buffer,
 	if (likely(size <= FM10K_RX_HDR_LEN)) {
 		memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
 
-		/* page is not reserved, we can reuse buffer as-is */
-		if (likely(!fm10k_page_is_reserved(page)))
+		/* page is reusable, we can reuse buffer as-is */
+		if (dev_page_is_reusable(page))
 			return true;
 
 		/* this page cannot be reused so discard it */
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 2574e78f7597..8d2ea4293d69 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1843,19 +1843,6 @@ static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb,
 	return false;
 }
 
-/**
- * i40e_page_is_reusable - check if any reuse is possible
- * @page: page struct to check
- *
- * A page is not reusable if it was allocated under low memory
- * conditions, or it's not in the same NUMA node as this CPU.
- */
-static inline bool i40e_page_is_reusable(struct page *page)
-{
-	return (page_to_nid(page) == numa_mem_id()) &&
-		!page_is_pfmemalloc(page);
-}
-
 /**
  * i40e_can_reuse_rx_page - Determine if this page can be reused by
  * the adapter for another receive
@@ -1891,7 +1878,7 @@ static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer,
 	struct page *page = rx_buffer->page;
 
 	/* Is any reuse possible? */
-	if (unlikely(!i40e_page_is_reusable(page)))
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_txrx.c b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
index 256fa07d54d5..ffaf2742a2e0 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_txrx.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
@@ -1141,19 +1141,6 @@ static void iavf_reuse_rx_page(struct iavf_ring *rx_ring,
 	new_buff->pagecnt_bias	= old_buff->pagecnt_bias;
 }
 
-/**
- * iavf_page_is_reusable - check if any reuse is possible
- * @page: page struct to check
- *
- * A page is not reusable if it was allocated under low memory
- * conditions, or it's not in the same NUMA node as this CPU.
- */
-static inline bool iavf_page_is_reusable(struct page *page)
-{
-	return (page_to_nid(page) == numa_mem_id()) &&
-		!page_is_pfmemalloc(page);
-}
-
 /**
  * iavf_can_reuse_rx_page - Determine if this page can be reused by
  * the adapter for another receive
@@ -1187,7 +1174,7 @@ static bool iavf_can_reuse_rx_page(struct iavf_rx_buffer *rx_buffer)
 	struct page *page = rx_buffer->page;
 
 	/* Is any reuse possible? */
-	if (unlikely(!iavf_page_is_reusable(page)))
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 2c2de56e2824..8ca63c6a6ba4 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -728,15 +728,6 @@ bool ice_alloc_rx_bufs(struct ice_ring *rx_ring, u16 cleaned_count)
 	return !!cleaned_count;
 }
 
-/**
- * ice_page_is_reserved - check if reuse is possible
- * @page: page struct to check
- */
-static bool ice_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 /**
  * ice_rx_buf_adjust_pg_offset - Prepare Rx buffer for reuse
  * @rx_buf: Rx buffer to adjust
@@ -775,8 +766,8 @@ ice_can_reuse_rx_page(struct ice_rx_buf *rx_buf, int rx_buf_pgcnt)
 	unsigned int pagecnt_bias = rx_buf->pagecnt_bias;
 	struct page *page = rx_buf->page;
 
-	/* avoid re-using remote pages */
-	if (unlikely(ice_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 84d4284b8b32..7d8e02b4d092 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -8215,18 +8215,13 @@ static void igb_reuse_rx_page(struct igb_ring *rx_ring,
 	new_buff->pagecnt_bias	= old_buff->pagecnt_bias;
 }
 
-static inline bool igb_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 static bool igb_can_reuse_rx_page(struct igb_rx_buffer *rx_buffer)
 {
 	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
 	struct page *page = rx_buffer->page;
 
-	/* avoid re-using remote pages */
-	if (unlikely(igb_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 43aec42e6d9d..ae0de7f08568 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1648,18 +1648,13 @@ static void igc_reuse_rx_page(struct igc_ring *rx_ring,
 	new_buff->pagecnt_bias	= old_buff->pagecnt_bias;
 }
 
-static inline bool igc_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 static bool igc_can_reuse_rx_page(struct igc_rx_buffer *rx_buffer)
 {
 	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
 	struct page *page = rx_buffer->page;
 
-	/* avoid re-using remote pages */
-	if (unlikely(igc_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index e08c01525fd2..237e09342f28 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1940,19 +1940,14 @@ static void ixgbe_reuse_rx_page(struct ixgbe_ring *rx_ring,
 	new_buff->pagecnt_bias	= old_buff->pagecnt_bias;
 }
 
-static inline bool ixgbe_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 static bool ixgbe_can_reuse_rx_page(struct ixgbe_rx_buffer *rx_buffer,
 				    int rx_buffer_pgcnt)
 {
 	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
 	struct page *page = rx_buffer->page;
 
-	/* avoid re-using remote pages */
-	if (unlikely(ixgbe_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index a14e55e7fce8..449d7d5b280d 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -781,18 +781,13 @@ static void ixgbevf_reuse_rx_page(struct ixgbevf_ring *rx_ring,
 	new_buff->pagecnt_bias = old_buff->pagecnt_bias;
 }
 
-static inline bool ixgbevf_page_is_reserved(struct page *page)
-{
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
-}
-
 static bool ixgbevf_can_reuse_rx_page(struct ixgbevf_rx_buffer *rx_buffer)
 {
 	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
 	struct page *page = rx_buffer->page;
 
-	/* avoid re-using remote pages */
-	if (unlikely(ixgbevf_page_is_reserved(page)))
+	/* avoid re-using remote and pfmemalloc pages */
+	if (!dev_page_is_reusable(page))
 		return false;
 
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 98b56f495b32..e1b4cf506a15 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -213,11 +213,6 @@ static inline u32 mlx5e_decompress_cqes_start(struct mlx5e_rq *rq,
 	return mlx5e_decompress_cqes_cont(rq, wq, 1, budget_rem) - 1;
 }
 
-static inline bool mlx5e_page_is_reserved(struct page *page)
-{
-	return page_is_pfmemalloc(page) || page_to_nid(page) != numa_mem_id();
-}
-
 static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
 				      struct mlx5e_dma_info *dma_info)
 {
@@ -230,7 +225,7 @@ static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
 		return false;
 	}
 
-	if (unlikely(mlx5e_page_is_reserved(dma_info->page))) {
+	if (!dev_page_is_reusable(dma_info->page)) {
 		stats->cache_waive++;
 		return false;
 	}
-- 
2.30.0

Re: [PATCH v3 net-next 1/5] mm: constify page_is_pfmemalloc() argument

[Matthew Wilcox]

On Sun, Jan 31, 2021 at 12:11:30PM +0000, Alexander Lobakin wrote:
> The function only tests for page->index, so its argument should be
> const.
> 
> Signed-off-by: Alexander Lobakin <alobakin@pm.me>
> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
> Acked-by: David Rientjes <rientjes@google.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Re: [PATCH v3 net-next 3/5] net: introduce common dev_page_is_reusable()

[Matthew Wilcox]

On Sun, Jan 31, 2021 at 12:11:52PM +0000, Alexander Lobakin wrote:
> A bunch of drivers test the page before reusing/recycling for two
> common conditions:
>  - if a page was allocated under memory pressure (pfmemalloc page);
>  - if a page was allocated at a distant memory node (to exclude
>    slowdowns).
> 
> Introduce a new common inline for doing this, with likely() already
> folded inside to make driver code a bit simpler.

I don't see the need for the 'dev_' prefix.  That actually confuses me
because it makes me think this is tied to ZONE_DEVICE or some such.

So how about calling it just 'page_is_reusable' and putting it in mm.h
with page_is_pfmemalloc() and making the comment a little less network-centric?

Or call it something like skb_page_is_recyclable() since it's only used
by networking today.  But I bet it could/should be used more widely.

> +/**
> + * dev_page_is_reusable - check whether a page can be reused for network Rx
> + * @page: the page to test
> + *
> + * A page shouldn't be considered for reusing/recycling if it was allocated
> + * under memory pressure or at a distant memory node.
> + *
> + * Returns false if this page should be returned to page allocator, true
> + * otherwise.
> + */
> +static inline bool dev_page_is_reusable(const struct page *page)
> +{
> +	return likely(page_to_nid(page) == numa_mem_id() &&
> +		      !page_is_pfmemalloc(page));
> +}
> +

Re: [PATCH v3 net-next 3/5] net: introduce common dev_page_is_reusable()

[Alexander Lobakin]

From: Matthew Wilcox <willy@infradead.org>
Date: Sun, 31 Jan 2021 12:22:05 +0000

> On Sun, Jan 31, 2021 at 12:11:52PM +0000, Alexander Lobakin wrote:
> > A bunch of drivers test the page before reusing/recycling for two
> > common conditions:
> >  - if a page was allocated under memory pressure (pfmemalloc page);
> >  - if a page was allocated at a distant memory node (to exclude
> >    slowdowns).
> >
> > Introduce a new common inline for doing this, with likely() already
> > folded inside to make driver code a bit simpler.
> 
> I don't see the need for the 'dev_' prefix.  That actually confuses me
> because it makes me think this is tied to ZONE_DEVICE or some such.

Several functions right above this one also use 'dev_' prefix. It's
a rather old mark that it's about network devices.

> So how about calling it just 'page_is_reusable' and putting it in mm.h
> with page_is_pfmemalloc() and making the comment a little less network-centric?

This pair of conditions (!pfmemalloc + local memory node) is really
specific to network drivers. I didn't see any other instances of such
tests, so I don't see a reason to place it in a more common mm.h.

> Or call it something like skb_page_is_recyclable() since it's only used
> by networking today.  But I bet it could/should be used more widely.

There's nothing about skb. Tested page is just a memory chunk for DMA
transaction. It can be used as skb head/frag, for XDP buffer/frame or
for XSK umem.

> > +/**
> > + * dev_page_is_reusable - check whether a page can be reused for network Rx
> > + * @page: the page to test
> > + *
> > + * A page shouldn't be considered for reusing/recycling if it was allocated
> > + * under memory pressure or at a distant memory node.
> > + *
> > + * Returns false if this page should be returned to page allocator, true
> > + * otherwise.
> > + */
> > +static inline bool dev_page_is_reusable(const struct page *page)
> > +{
> > +	return likely(page_to_nid(page) == numa_mem_id() &&
> > +		      !page_is_pfmemalloc(page));
> > +}
> > +

Al

Re: [PATCH v3 net-next 5/5] net: page_pool: simplify page recycling condition tests

[Matthew Wilcox]

On Sun, Jan 31, 2021 at 12:12:11PM +0000, Alexander Lobakin wrote:
> pool_page_reusable() is a leftover from pre-NUMA-aware times. For now,
> this function is just a redundant wrapper over page_is_pfmemalloc(),
> so inline it into its sole call site.

Why doesn't this want to use {dev_}page_is_reusable()?

Re: [PATCH v3 net-next 0/5] net: consolidate page_is_pfmemalloc() usage

[Jakub Kicinski]

On Sun, 31 Jan 2021 12:11:16 +0000 Alexander Lobakin wrote:
> page_is_pfmemalloc() is used mostly by networking drivers to test
> if a page can be considered for reusing/recycling.
> It doesn't write anything to the struct page itself, so its sole
> argument can be constified, as well as the first argument of
> skb_propagate_pfmemalloc().
> In Page Pool core code, it can be simply inlined instead.
> Most of the callers from NIC drivers were just doppelgangers of
> the same condition tests. Derive them into a new common function
> do deduplicate the code.

Please resend, this did not get into patchwork :/

Re: [PATCH v3 net-next 0/5] net: consolidate page_is_pfmemalloc() usage

[Alexander Lobakin]

From: Jakub Kicinski <kuba@kernel.org>
Date: Mon, 1 Feb 2021 17:18:35 -0800

> On Sun, 31 Jan 2021 12:11:16 +0000 Alexander Lobakin wrote:
> > page_is_pfmemalloc() is used mostly by networking drivers to test
> > if a page can be considered for reusing/recycling.
> > It doesn't write anything to the struct page itself, so its sole
> > argument can be constified, as well as the first argument of
> > skb_propagate_pfmemalloc().
> > In Page Pool core code, it can be simply inlined instead.
> > Most of the callers from NIC drivers were just doppelgangers of
> > the same condition tests. Derive them into a new common function
> > do deduplicate the code.
> 
> Please resend, this did not get into patchwork :/

I suspected it would be so as I got reports about undelivered mails
due to unavailability of vger.kernel.org for some reasons Will do.

Al