| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <1348750077.5093.1224.camel@edumazet-glaptop>
Date: Thu, 27 Sep 2012 14:47:57 +0200
From: Eric Dumazet <eric.dumazet@...il.com>
To: David Miller <davem@...emloft.net>
Cc: netdev <netdev@...r.kernel.org>
Subject: [PATCH net-next 2/3] net: add gro_cells infrastructure
From: Eric Dumazet <edumazet@...gle.com>
This adds a new include file (include/net/gro_cells.h), to bring GRO
(Generic Receive Offload) capability to tunnels, in a modular way.
Because tunnels receive path is lockless, and GRO adds a serialization
using a napi_struct, I chose to add an array of up to 8 cells,
so that multi queue devices wont be slowed down because of GRO layer.
skb_get_rx_queue() is used as selector.
In the future, we might add optional fanout capabilities, using rxhash
for example.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
include/net/gro_cells.h | 103 ++++++++++++++++++++++++++++++++++++++
net/core/dev.c | 2
2 files changed, 105 insertions(+)
diff --git a/include/net/gro_cells.h b/include/net/gro_cells.h
new file mode 100644
index 0000000..ba93b1b
--- /dev/null
+++ b/include/net/gro_cells.h
@@ -0,0 +1,103 @@
+#ifndef _NET_GRO_CELLS_H
+#define _NET_GRO_CELLS_H
+
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+
+struct gro_cell {
+ struct sk_buff_head napi_skbs;
+ struct napi_struct napi;
+} ____cacheline_aligned_in_smp;
+
+struct gro_cells {
+ unsigned int gro_cells_mask;
+ struct gro_cell *cells;
+};
+
+static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
+{
+ unsigned long flags;
+ struct gro_cell *cell = gcells->cells;
+ struct net_device *dev = skb->dev;
+
+ if (!cell || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
+ netif_rx(skb);
+ return;
+ }
+
+ if (skb_rx_queue_recorded(skb))
+ cell += skb_get_rx_queue(skb) & gcells->gro_cells_mask;
+
+ if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
+ atomic_long_inc(&dev->rx_dropped);
+ kfree_skb(skb);
+ return;
+ }
+
+ spin_lock_irqsave(&cell->napi_skbs.lock, flags);
+
+ __skb_queue_tail(&cell->napi_skbs, skb);
+ if (skb_queue_len(&cell->napi_skbs) == 1)
+ napi_schedule(&cell->napi);
+
+ spin_unlock_irqrestore(&cell->napi_skbs.lock, flags);
+}
+
+static inline int gro_cell_poll(struct napi_struct *napi, int budget)
+{
+ struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
+ struct sk_buff *skb;
+ int work_done = 0;
+
+ while (work_done < budget) {
+ skb = skb_dequeue(&cell->napi_skbs);
+ if (!skb)
+ break;
+
+ napi_gro_receive(napi, skb);
+ work_done++;
+ }
+
+ if (work_done < budget)
+ napi_complete(napi);
+ return work_done;
+}
+
+static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
+{
+ int i;
+
+ gcells->gro_cells_mask = roundup_pow_of_two(min_t(unsigned int, 8, nr_cpu_ids)) - 1;
+ gcells->cells = kcalloc(sizeof(struct gro_cell),
+ gcells->gro_cells_mask + 1,
+ GFP_KERNEL);
+ if (!gcells->cells)
+ return -ENOMEM;
+
+ for (i = 0; i <= gcells->gro_cells_mask; i++) {
+ struct gro_cell *cell = gcells->cells + i;
+
+ skb_queue_head_init(&cell->napi_skbs);
+ netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
+ napi_enable(&cell->napi);
+ }
+ return 0;
+}
+
+static inline void gro_cells_destroy(struct gro_cells *gcells)
+{
+ struct gro_cell *cell = gcells->cells;
+ int i;
+
+ if (!cell)
+ return;
+ for (i = 0; i <= gcells->gro_cells_mask; i++,cell++) {
+ netif_napi_del(&cell->napi);
+ skb_queue_purge(&cell->napi_skbs);
+ }
+ kfree(gcells->cells);
+ gcells->cells = NULL;
+}
+
+#endif
diff --git a/net/core/dev.c b/net/core/dev.c
index 707b124..9f63660 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2644,6 +2644,8 @@ EXPORT_SYMBOL(dev_queue_xmit);
=======================================================================*/
int netdev_max_backlog __read_mostly = 1000;
+EXPORT_SYMBOL(netdev_max_backlog);
+
int netdev_tstamp_prequeue __read_mostly = 1;
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64; /* old backlog weight */
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists