On Sun, 12 Feb 2023 at 04:22, Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> 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 > continuous physical memory that will cause the start failure. nit: contiguous But perfectly understandable without fixing this. > 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. Thanks for improving/fixing this. Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Link: https://lore.kernel.org/oe-kbuild-all/202302091850.0HBmsDAq-lkp@xxxxxxxxx > --- > > v2: > 1. remove __get_free_pages() @Magnus Karlsson > > net/xdp/xsk.c | 9 ++------- > net/xdp/xsk_queue.c | 10 ++++------ > net/xdp/xsk_queue.h | 1 + > 3 files changed, 7 insertions(+), 13 deletions(-) > > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c > index 9f0561b67c12..6a588b99b670 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 > PAGE_ALIGN(q->ring_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..247316bdfcbe 100644 > --- a/net/xdp/xsk_queue.c > +++ b/net/xdp/xsk_queue.c > @@ -7,6 +7,7 @@ > #include <linux/slab.h> > #include <linux/overflow.h> > #include <net/xdp_sock_drv.h> > +#include <linux/vmalloc.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); > @@ -33,12 +33,10 @@ 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); > > - q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags, > - get_order(size)); > + q->ring_size = size; > + q->ring = (struct xdp_ring *)vmalloc_user(size); > if (!q->ring) { > kfree(q); > return NULL; > @@ -52,6 +50,6 @@ 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..35922b8b92a8 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_size; > }; > > /* The structure of the shared state of the rings are a simple > -- > 2.32.0.3.g01195cf9f >
