]> git.ipfire.org Git - ipfire-2.x.git/blame - src/patches/suse-2.6.27.39/patches.xen/xen-netback-nr-irqs
Imported linux-2.6.27.39 suse/xen patches.
[ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.xen / xen-netback-nr-irqs
CommitLineData
2cb7cef9
BS
1From: jbeulich@novell.com
2Subject: netback: reduce overhead of IRQ recording
3Patch-mainline: obsolete
4
5Since both NR_PIRQS and NR_DYNIRQS are no longer hardcoded, the
6(memory) overhead of tracking which ones to send notifications to can
7be pretty unbounded. Also, store the dynirq rather than the raw irq
8to push up the limit where the type of notify_list needs to become
9'int' rather than 'u16'.
10
11--- head-2009-02-02.orig/drivers/xen/netback/interface.c 2009-02-02 09:40:43.000000000 +0100
12+++ head-2009-02-02/drivers/xen/netback/interface.c 2009-02-02 10:20:51.000000000 +0100
13@@ -280,6 +280,7 @@ int netif_map(netif_t *netif, unsigned l
14 netif->dev->name, netif);
15 if (err < 0)
16 goto err_hypervisor;
17+ BUG_ON(err < DYNIRQ_BASE || err >= DYNIRQ_BASE + NR_DYNIRQS);
18 netif->irq = err;
19 disable_irq(netif->irq);
20
21--- head-2009-02-02.orig/drivers/xen/netback/netback.c 2008-12-23 09:35:35.000000000 +0100
22+++ head-2009-02-02/drivers/xen/netback/netback.c 2008-12-23 09:35:42.000000000 +0100
23@@ -580,8 +580,12 @@ static void net_rx_action(unsigned long
24 static mmu_update_t rx_mmu[NET_RX_RING_SIZE];
25 static gnttab_transfer_t grant_trans_op[NET_RX_RING_SIZE];
26 static gnttab_copy_t grant_copy_op[NET_RX_RING_SIZE];
27- static unsigned char rx_notify[NR_IRQS];
28+ static DECLARE_BITMAP(rx_notify, NR_DYNIRQS);
29+#if NR_DYNIRQS <= 0x10000
30 static u16 notify_list[NET_RX_RING_SIZE];
31+#else
32+ static int notify_list[NET_RX_RING_SIZE];
33+#endif
34 static struct netbk_rx_meta meta[NET_RX_RING_SIZE];
35
36 struct netrx_pending_operations npo = {
37@@ -730,11 +734,9 @@ static void net_rx_action(unsigned long
38 nr_frags);
39
40 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netif->rx, ret);
41- irq = netif->irq;
42- if (ret && !rx_notify[irq]) {
43- rx_notify[irq] = 1;
44+ irq = netif->irq - DYNIRQ_BASE;
45+ if (ret && !__test_and_set_bit(irq, rx_notify))
46 notify_list[notify_nr++] = irq;
47- }
48
49 if (netif_queue_stopped(netif->dev) &&
50 netif_schedulable(netif) &&
51@@ -748,8 +750,8 @@ static void net_rx_action(unsigned long
52
53 while (notify_nr != 0) {
54 irq = notify_list[--notify_nr];
55- rx_notify[irq] = 0;
56- notify_remote_via_irq(irq);
57+ __clear_bit(irq, rx_notify);
58+ notify_remote_via_irq(irq + DYNIRQ_BASE);
59 }
60
61 /* More work to do? */