Revision 6e474083f3daf3a3546737f5d7d502ad12eb257c authored by Wei Xu on 01 December 2017, 10:10:36 UTC, committed by David S. Miller on 03 December 2017, 02:31:03 UTC
Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest can not drain out vq as fast as vhost fills in, afterwards it sets off the traffic jam and leaks skb(s) which occurs as no headcount to send on the vq from vhost side. This can be avoided by making sure we have got enough headcount before actually consuming a skb from the batched rx array while transmitting, which is simply done by moving checking the zero headcount a bit ahead. Signed-off-by: Wei Xu <wexu@redhat.com> Reported-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent fa935ca
xxs1500_ss.c
/*
* PCMCIA socket code for the MyCable XXS1500 system.
*
* Copyright (c) 2009 Manuel Lauss <manuel.lauss@gmail.com>
*
*/
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/resource.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <pcmcia/ss.h>
#include <pcmcia/cistpl.h>
#include <asm/irq.h>
#include <asm/mach-au1x00/au1000.h>
#define MEM_MAP_SIZE 0x400000
#define IO_MAP_SIZE 0x1000
/*
* 3.3V cards only; all interfacing is done via gpios:
*
* 0/1: carddetect (00 = card present, xx = huh)
* 4: card irq
* 204: reset (high-act)
* 205: buffer enable (low-act)
* 208/209: card voltage key (00,01,10,11)
* 210: battwarn
* 211: batdead
* 214: power (low-act)
*/
#define GPIO_CDA 0
#define GPIO_CDB 1
#define GPIO_CARDIRQ 4
#define GPIO_RESET 204
#define GPIO_OUTEN 205
#define GPIO_VSL 208
#define GPIO_VSH 209
#define GPIO_BATTDEAD 210
#define GPIO_BATTWARN 211
#define GPIO_POWER 214
struct xxs1500_pcmcia_sock {
struct pcmcia_socket socket;
void *virt_io;
phys_addr_t phys_io;
phys_addr_t phys_attr;
phys_addr_t phys_mem;
/* previous flags for set_socket() */
unsigned int old_flags;
};
#define to_xxs_socket(x) container_of(x, struct xxs1500_pcmcia_sock, socket)
static irqreturn_t cdirq(int irq, void *data)
{
struct xxs1500_pcmcia_sock *sock = data;
pcmcia_parse_events(&sock->socket, SS_DETECT);
return IRQ_HANDLED;
}
static int xxs1500_pcmcia_configure(struct pcmcia_socket *skt,
struct socket_state_t *state)
{
struct xxs1500_pcmcia_sock *sock = to_xxs_socket(skt);
unsigned int changed;
/* power control */
switch (state->Vcc) {
case 0:
gpio_set_value(GPIO_POWER, 1); /* power off */
break;
case 33:
gpio_set_value(GPIO_POWER, 0); /* power on */
break;
case 50:
default:
return -EINVAL;
}
changed = state->flags ^ sock->old_flags;
if (changed & SS_RESET) {
if (state->flags & SS_RESET) {
gpio_set_value(GPIO_RESET, 1); /* assert reset */
gpio_set_value(GPIO_OUTEN, 1); /* buffers off */
} else {
gpio_set_value(GPIO_RESET, 0); /* deassert reset */
gpio_set_value(GPIO_OUTEN, 0); /* buffers on */
msleep(500);
}
}
sock->old_flags = state->flags;
return 0;
}
static int xxs1500_pcmcia_get_status(struct pcmcia_socket *skt,
unsigned int *value)
{
unsigned int status;
int i;
status = 0;
/* check carddetects: GPIO[0:1] must both be low */
if (!gpio_get_value(GPIO_CDA) && !gpio_get_value(GPIO_CDB))
status |= SS_DETECT;
/* determine card voltage: GPIO[208:209] binary value */
i = (!!gpio_get_value(GPIO_VSL)) | ((!!gpio_get_value(GPIO_VSH)) << 1);
switch (i) {
case 0:
case 1:
case 2:
status |= SS_3VCARD; /* 3V card */
break;
case 3: /* 5V card, unsupported */
default:
status |= SS_XVCARD; /* treated as unsupported in core */
}
/* GPIO214: low active power switch */
status |= gpio_get_value(GPIO_POWER) ? 0 : SS_POWERON;
/* GPIO204: high-active reset line */
status |= gpio_get_value(GPIO_RESET) ? SS_RESET : SS_READY;
/* other stuff */
status |= gpio_get_value(GPIO_BATTDEAD) ? 0 : SS_BATDEAD;
status |= gpio_get_value(GPIO_BATTWARN) ? 0 : SS_BATWARN;
*value = status;
return 0;
}
static int xxs1500_pcmcia_sock_init(struct pcmcia_socket *skt)
{
gpio_direction_input(GPIO_CDA);
gpio_direction_input(GPIO_CDB);
gpio_direction_input(GPIO_VSL);
gpio_direction_input(GPIO_VSH);
gpio_direction_input(GPIO_BATTDEAD);
gpio_direction_input(GPIO_BATTWARN);
gpio_direction_output(GPIO_RESET, 1); /* assert reset */
gpio_direction_output(GPIO_OUTEN, 1); /* disable buffers */
gpio_direction_output(GPIO_POWER, 1); /* power off */
return 0;
}
static int xxs1500_pcmcia_sock_suspend(struct pcmcia_socket *skt)
{
return 0;
}
static int au1x00_pcmcia_set_io_map(struct pcmcia_socket *skt,
struct pccard_io_map *map)
{
struct xxs1500_pcmcia_sock *sock = to_xxs_socket(skt);
map->start = (u32)sock->virt_io;
map->stop = map->start + IO_MAP_SIZE;
return 0;
}
static int au1x00_pcmcia_set_mem_map(struct pcmcia_socket *skt,
struct pccard_mem_map *map)
{
struct xxs1500_pcmcia_sock *sock = to_xxs_socket(skt);
if (map->flags & MAP_ATTRIB)
map->static_start = sock->phys_attr + map->card_start;
else
map->static_start = sock->phys_mem + map->card_start;
return 0;
}
static struct pccard_operations xxs1500_pcmcia_operations = {
.init = xxs1500_pcmcia_sock_init,
.suspend = xxs1500_pcmcia_sock_suspend,
.get_status = xxs1500_pcmcia_get_status,
.set_socket = xxs1500_pcmcia_configure,
.set_io_map = au1x00_pcmcia_set_io_map,
.set_mem_map = au1x00_pcmcia_set_mem_map,
};
static int xxs1500_pcmcia_probe(struct platform_device *pdev)
{
struct xxs1500_pcmcia_sock *sock;
struct resource *r;
int ret, irq;
sock = kzalloc(sizeof(struct xxs1500_pcmcia_sock), GFP_KERNEL);
if (!sock)
return -ENOMEM;
ret = -ENODEV;
/* 36bit PCMCIA Attribute area address */
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcmcia-attr");
if (!r) {
dev_err(&pdev->dev, "missing 'pcmcia-attr' resource!\n");
goto out0;
}
sock->phys_attr = r->start;
/* 36bit PCMCIA Memory area address */
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcmcia-mem");
if (!r) {
dev_err(&pdev->dev, "missing 'pcmcia-mem' resource!\n");
goto out0;
}
sock->phys_mem = r->start;
/* 36bit PCMCIA IO area address */
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcmcia-io");
if (!r) {
dev_err(&pdev->dev, "missing 'pcmcia-io' resource!\n");
goto out0;
}
sock->phys_io = r->start;
/*
* PCMCIA client drivers use the inb/outb macros to access
* the IO registers. Since mips_io_port_base is added
* to the access address of the mips implementation of
* inb/outb, we need to subtract it here because we want
* to access the I/O or MEM address directly, without
* going through this "mips_io_port_base" mechanism.
*/
sock->virt_io = (void *)(ioremap(sock->phys_io, IO_MAP_SIZE) -
mips_io_port_base);
if (!sock->virt_io) {
dev_err(&pdev->dev, "cannot remap IO area\n");
ret = -ENOMEM;
goto out0;
}
sock->socket.ops = &xxs1500_pcmcia_operations;
sock->socket.owner = THIS_MODULE;
sock->socket.pci_irq = gpio_to_irq(GPIO_CARDIRQ);
sock->socket.features = SS_CAP_STATIC_MAP | SS_CAP_PCCARD;
sock->socket.map_size = MEM_MAP_SIZE;
sock->socket.io_offset = (unsigned long)sock->virt_io;
sock->socket.dev.parent = &pdev->dev;
sock->socket.resource_ops = &pccard_static_ops;
platform_set_drvdata(pdev, sock);
/* setup carddetect irq: use one of the 2 GPIOs as an
* edge detector.
*/
irq = gpio_to_irq(GPIO_CDA);
irq_set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
ret = request_irq(irq, cdirq, 0, "pcmcia_carddetect", sock);
if (ret) {
dev_err(&pdev->dev, "cannot setup cd irq\n");
goto out1;
}
ret = pcmcia_register_socket(&sock->socket);
if (ret) {
dev_err(&pdev->dev, "failed to register\n");
goto out2;
}
printk(KERN_INFO "MyCable XXS1500 PCMCIA socket services\n");
return 0;
out2:
free_irq(gpio_to_irq(GPIO_CDA), sock);
out1:
iounmap((void *)(sock->virt_io + (u32)mips_io_port_base));
out0:
kfree(sock);
return ret;
}
static int xxs1500_pcmcia_remove(struct platform_device *pdev)
{
struct xxs1500_pcmcia_sock *sock = platform_get_drvdata(pdev);
pcmcia_unregister_socket(&sock->socket);
free_irq(gpio_to_irq(GPIO_CDA), sock);
iounmap((void *)(sock->virt_io + (u32)mips_io_port_base));
kfree(sock);
return 0;
}
static struct platform_driver xxs1500_pcmcia_socket_driver = {
.driver = {
.name = "xxs1500_pcmcia",
},
.probe = xxs1500_pcmcia_probe,
.remove = xxs1500_pcmcia_remove,
};
module_platform_driver(xxs1500_pcmcia_socket_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PCMCIA Socket Services for MyCable XXS1500 systems");
MODULE_AUTHOR("Manuel Lauss");
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...