diff mbox series

[net-next,v4] xsk: support use vaddr as ring

Message ID 20230216083047.93525-1-xuanzhuo@linux.alibaba.com (mailing list archive)
State Accepted
Commit 9f78bf330a66cd400b3e00f370f597e9fa939207
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v4] xsk: support use vaddr as ring | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers success CCed 14 of 14 maintainers
netdev/build_clang success Errors and warnings before: 1 this patch: 1
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 71 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Xuan Zhuo Feb. 16, 2023, 8:30 a.m. UTC 
When we try to start AF_XDP on some machines with long running time, due
to the machine's memory fragmentation problem, there is no sufficient
contiguous physical memory that will cause the start failure.

If the size of the queue is 8 * 1024, then the size of the desc[] is
8 * 1024 * 8 = 16 * PAGE, but we also add struct xdp_ring size, so it is
16page+. This is necessary to apply for a 4-order memory. If there are a
lot of queues, it is difficult to these machine with long running time.

Here, that we actually waste 15 pages. 4-Order memory is 32 pages, but
we only use 17 pages.

This patch replaces __get_free_pages() by vmalloc() to allocate memory
to solve these problems.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
---
 net/xdp/xsk.c       |  9 ++-------
 net/xdp/xsk_queue.c | 11 +++++------
 net/xdp/xsk_queue.h |  1 +
 3 files changed, 8 insertions(+), 13 deletions(-)

Comments

Alexander Lobakin Feb. 16, 2023, 1:04 p.m. UTC | #1 
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: Thu, 16 Feb 2023 16:30:47 +0800

> When we try to start AF_XDP on some machines with long running time, due
> to the machine's memory fragmentation problem, there is no sufficient
> contiguous physical memory that will cause the start failure.
> 
> If the size of the queue is 8 * 1024, then the size of the desc[] is
> 8 * 1024 * 8 = 16 * PAGE, but we also add struct xdp_ring size, so it is
> 16page+. This is necessary to apply for a 4-order memory. If there are a
> lot of queues, it is difficult to these machine with long running time.
> 
> Here, that we actually waste 15 pages. 4-Order memory is 32 pages, but
> we only use 17 pages.
> 
> This patch replaces __get_free_pages() by vmalloc() to allocate memory
> to solve these problems.
> 
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
> ---

[...]

> diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
> index c6fb6b763658..bfb2a7e50c26 100644
> --- a/net/xdp/xsk_queue.h
> +++ b/net/xdp/xsk_queue.h
> @@ -45,6 +45,7 @@ struct xsk_queue {
>  	struct xdp_ring *ring;
>  	u64 invalid_descs;
>  	u64 queue_empty_descs;
> +	size_t ring_vmalloc_size;

The name looks a bit long to me, but that might be just personal
preference. The code itself now looks good to me.

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

>  };
>  
>  /* The structure of the shared state of the rings are a simple

Next time pls make sure you added all of the reviewers to the Cc list
when sending a new revision. I noticed you posted v4 only by monitoring
the ML.

Thanks,
Olek
Xuan Zhuo Feb. 17, 2023, 8:59 a.m. UTC | #2 
On Thu, 16 Feb 2023 14:04:47 +0100, Alexander Lobakin <aleksander.lobakin@intel.com> wrote:
> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> Date: Thu, 16 Feb 2023 16:30:47 +0800
>
> > When we try to start AF_XDP on some machines with long running time, due
> > to the machine's memory fragmentation problem, there is no sufficient
> > contiguous physical memory that will cause the start failure.
> >
> > If the size of the queue is 8 * 1024, then the size of the desc[] is
> > 8 * 1024 * 8 = 16 * PAGE, but we also add struct xdp_ring size, so it is
> > 16page+. This is necessary to apply for a 4-order memory. If there are a
> > lot of queues, it is difficult to these machine with long running time.
> >
> > Here, that we actually waste 15 pages. 4-Order memory is 32 pages, but
> > we only use 17 pages.
> >
> > This patch replaces __get_free_pages() by vmalloc() to allocate memory
> > to solve these problems.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
> > ---
>
> [...]
>
> > diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
> > index c6fb6b763658..bfb2a7e50c26 100644
> > --- a/net/xdp/xsk_queue.h
> > +++ b/net/xdp/xsk_queue.h
> > @@ -45,6 +45,7 @@ struct xsk_queue {
> >  	struct xdp_ring *ring;
> >  	u64 invalid_descs;
> >  	u64 queue_empty_descs;
> > +	size_t ring_vmalloc_size;
>
> The name looks a bit long to me, but that might be just personal
> preference. The code itself now looks good to me.
>
> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
>
> >  };
> >
> >  /* The structure of the shared state of the rings are a simple
>
> Next time pls make sure you added all of the reviewers to the Cc list
> when sending a new revision. I noticed you posted v4 only by monitoring
> the ML.

Oh, sorry. I always thought you were in the list. I did not notice this
situation.

I will pay attention next time. Thank you for your reply.

Thanks.


>
> Thanks,
> Olek
patchwork-bot+netdevbpf@kernel.org Feb. 20, 2023, 8:30 a.m. UTC | #3 
Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Thu, 16 Feb 2023 16:30:47 +0800 you wrote:
> When we try to start AF_XDP on some machines with long running time, due
> to the machine's memory fragmentation problem, there is no sufficient
> contiguous physical memory that will cause the start failure.
> 
> If the size of the queue is 8 * 1024, then the size of the desc[] is
> 8 * 1024 * 8 = 16 * PAGE, but we also add struct xdp_ring size, so it is
> 16page+. This is necessary to apply for a 4-order memory. If there are a
> lot of queues, it is difficult to these machine with long running time.
> 
> [...]

Here is the summary with links:
  - [net-next,v4] xsk: support use vaddr as ring
    https://git.kernel.org/netdev/net-next/c/9f78bf330a66

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 9f0561b67c12..0a047a09a10f 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -1295,8 +1295,6 @@  static int xsk_mmap(struct file *file, struct socket *sock,
 	unsigned long size = vma->vm_end - vma->vm_start;
 	struct xdp_sock *xs = xdp_sk(sock->sk);
 	struct xsk_queue *q = NULL;
-	unsigned long pfn;
-	struct page *qpg;
 
 	if (READ_ONCE(xs->state) != XSK_READY)
 		return -EBUSY;
@@ -1319,13 +1317,10 @@  static int xsk_mmap(struct file *file, struct socket *sock,
 
 	/* Matches the smp_wmb() in xsk_init_queue */
 	smp_rmb();
-	qpg = virt_to_head_page(q->ring);
-	if (size > page_size(qpg))
+	if (size > q->ring_vmalloc_size)
 		return -EINVAL;
 
-	pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
-	return remap_pfn_range(vma, vma->vm_start, pfn,
-			       size, vma->vm_page_prot);
+	return remap_vmalloc_range(vma, q->ring, 0);
 }
 
 static int xsk_notifier(struct notifier_block *this,
diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c
index 6cf9586e5027..f8905400ee07 100644
--- a/net/xdp/xsk_queue.c
+++ b/net/xdp/xsk_queue.c
@@ -6,6 +6,7 @@ 
 #include <linux/log2.h>
 #include <linux/slab.h>
 #include <linux/overflow.h>
+#include <linux/vmalloc.h>
 #include <net/xdp_sock_drv.h>
 
 #include "xsk_queue.h"
@@ -23,7 +24,6 @@  static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
 {
 	struct xsk_queue *q;
-	gfp_t gfp_flags;
 	size_t size;
 
 	q = kzalloc(sizeof(*q), GFP_KERNEL);
@@ -33,17 +33,16 @@  struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
 	q->nentries = nentries;
 	q->ring_mask = nentries - 1;
 
-	gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
-		    __GFP_COMP  | __GFP_NORETRY;
 	size = xskq_get_ring_size(q, umem_queue);
+	size = PAGE_ALIGN(size);
 
-	q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
-						      get_order(size));
+	q->ring = vmalloc_user(size);
 	if (!q->ring) {
 		kfree(q);
 		return NULL;
 	}
 
+	q->ring_vmalloc_size = size;
 	return q;
 }
 
@@ -52,6 +51,6 @@  void xskq_destroy(struct xsk_queue *q)
 	if (!q)
 		return;
 
-	page_frag_free(q->ring);
+	vfree(q->ring);
 	kfree(q);
 }
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index c6fb6b763658..bfb2a7e50c26 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -45,6 +45,7 @@  struct xsk_queue {
 	struct xdp_ring *ring;
 	u64 invalid_descs;
 	u64 queue_empty_descs;
+	size_t ring_vmalloc_size;
 };
 
 /* The structure of the shared state of the rings are a simple