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
electra_cf.c
/*
* Copyright (C) 2007 PA Semi, Inc
*
* Maintained by: Olof Johansson <olof@lixom.net>
*
* Based on drivers/pcmcia/omap_cf.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <pcmcia/ss.h>
static const char driver_name[] = "electra-cf";
struct electra_cf_socket {
struct pcmcia_socket socket;
struct timer_list timer;
unsigned present:1;
unsigned active:1;
struct platform_device *ofdev;
unsigned long mem_phys;
void __iomem *mem_base;
unsigned long mem_size;
void __iomem *io_virt;
unsigned int io_base;
unsigned int io_size;
u_int irq;
struct resource iomem;
void __iomem *gpio_base;
int gpio_detect;
int gpio_vsense;
int gpio_3v;
int gpio_5v;
};
#define POLL_INTERVAL (2 * HZ)
static int electra_cf_present(struct electra_cf_socket *cf)
{
unsigned int gpio;
gpio = in_le32(cf->gpio_base+0x40);
return !(gpio & (1 << cf->gpio_detect));
}
static int electra_cf_ss_init(struct pcmcia_socket *s)
{
return 0;
}
/* the timer is primarily to kick this socket's pccardd */
static void electra_cf_timer(struct timer_list *t)
{
struct electra_cf_socket *cf = from_timer(cf, t, timer);
int present = electra_cf_present(cf);
if (present != cf->present) {
cf->present = present;
pcmcia_parse_events(&cf->socket, SS_DETECT);
}
if (cf->active)
mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
}
static irqreturn_t electra_cf_irq(int irq, void *_cf)
{
struct electra_cf_socket *cf = _cf;
electra_cf_timer(&cf->timer);
return IRQ_HANDLED;
}
static int electra_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
struct electra_cf_socket *cf;
if (!sp)
return -EINVAL;
cf = container_of(s, struct electra_cf_socket, socket);
/* NOTE CF is always 3VCARD */
if (electra_cf_present(cf)) {
*sp = SS_READY | SS_DETECT | SS_POWERON | SS_3VCARD;
s->pci_irq = cf->irq;
} else
*sp = 0;
return 0;
}
static int electra_cf_set_socket(struct pcmcia_socket *sock,
struct socket_state_t *s)
{
unsigned int gpio;
unsigned int vcc;
struct electra_cf_socket *cf;
cf = container_of(sock, struct electra_cf_socket, socket);
/* "reset" means no power in our case */
vcc = (s->flags & SS_RESET) ? 0 : s->Vcc;
switch (vcc) {
case 0:
gpio = 0;
break;
case 33:
gpio = (1 << cf->gpio_3v);
break;
case 5:
gpio = (1 << cf->gpio_5v);
break;
default:
return -EINVAL;
}
gpio |= 1 << (cf->gpio_3v + 16); /* enwr */
gpio |= 1 << (cf->gpio_5v + 16); /* enwr */
out_le32(cf->gpio_base+0x90, gpio);
pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x\n",
driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);
return 0;
}
static int electra_cf_set_io_map(struct pcmcia_socket *s,
struct pccard_io_map *io)
{
return 0;
}
static int electra_cf_set_mem_map(struct pcmcia_socket *s,
struct pccard_mem_map *map)
{
struct electra_cf_socket *cf;
if (map->card_start)
return -EINVAL;
cf = container_of(s, struct electra_cf_socket, socket);
map->static_start = cf->mem_phys;
map->flags &= MAP_ACTIVE|MAP_ATTRIB;
if (!(map->flags & MAP_ATTRIB))
map->static_start += 0x800;
return 0;
}
static struct pccard_operations electra_cf_ops = {
.init = electra_cf_ss_init,
.get_status = electra_cf_get_status,
.set_socket = electra_cf_set_socket,
.set_io_map = electra_cf_set_io_map,
.set_mem_map = electra_cf_set_mem_map,
};
static int electra_cf_probe(struct platform_device *ofdev)
{
struct device *device = &ofdev->dev;
struct device_node *np = ofdev->dev.of_node;
struct electra_cf_socket *cf;
struct resource mem, io;
int status;
const unsigned int *prop;
int err;
struct vm_struct *area;
err = of_address_to_resource(np, 0, &mem);
if (err)
return -EINVAL;
err = of_address_to_resource(np, 1, &io);
if (err)
return -EINVAL;
cf = kzalloc(sizeof(*cf), GFP_KERNEL);
if (!cf)
return -ENOMEM;
timer_setup(&cf->timer, electra_cf_timer, 0);
cf->irq = 0;
cf->ofdev = ofdev;
cf->mem_phys = mem.start;
cf->mem_size = PAGE_ALIGN(resource_size(&mem));
cf->mem_base = ioremap(cf->mem_phys, cf->mem_size);
cf->io_size = PAGE_ALIGN(resource_size(&io));
area = __get_vm_area(cf->io_size, 0, PHB_IO_BASE, PHB_IO_END);
if (area == NULL) {
status = -ENOMEM;
goto fail1;
}
cf->io_virt = (void __iomem *)(area->addr);
cf->gpio_base = ioremap(0xfc103000, 0x1000);
dev_set_drvdata(device, cf);
if (!cf->mem_base || !cf->io_virt || !cf->gpio_base ||
(__ioremap_at(io.start, cf->io_virt, cf->io_size,
pgprot_val(pgprot_noncached(__pgprot(0)))) == NULL)) {
dev_err(device, "can't ioremap ranges\n");
status = -ENOMEM;
goto fail1;
}
cf->io_base = (unsigned long)cf->io_virt - VMALLOC_END;
cf->iomem.start = (unsigned long)cf->mem_base;
cf->iomem.end = (unsigned long)cf->mem_base + (mem.end - mem.start);
cf->iomem.flags = IORESOURCE_MEM;
cf->irq = irq_of_parse_and_map(np, 0);
status = request_irq(cf->irq, electra_cf_irq, IRQF_SHARED,
driver_name, cf);
if (status < 0) {
dev_err(device, "request_irq failed\n");
goto fail1;
}
cf->socket.pci_irq = cf->irq;
prop = of_get_property(np, "card-detect-gpio", NULL);
if (!prop)
goto fail1;
cf->gpio_detect = *prop;
prop = of_get_property(np, "card-vsense-gpio", NULL);
if (!prop)
goto fail1;
cf->gpio_vsense = *prop;
prop = of_get_property(np, "card-3v-gpio", NULL);
if (!prop)
goto fail1;
cf->gpio_3v = *prop;
prop = of_get_property(np, "card-5v-gpio", NULL);
if (!prop)
goto fail1;
cf->gpio_5v = *prop;
cf->socket.io_offset = cf->io_base;
/* reserve chip-select regions */
if (!request_mem_region(cf->mem_phys, cf->mem_size, driver_name)) {
status = -ENXIO;
dev_err(device, "Can't claim memory region\n");
goto fail1;
}
if (!request_region(cf->io_base, cf->io_size, driver_name)) {
status = -ENXIO;
dev_err(device, "Can't claim I/O region\n");
goto fail2;
}
cf->socket.owner = THIS_MODULE;
cf->socket.dev.parent = &ofdev->dev;
cf->socket.ops = &electra_cf_ops;
cf->socket.resource_ops = &pccard_static_ops;
cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP |
SS_CAP_MEM_ALIGN;
cf->socket.map_size = 0x800;
status = pcmcia_register_socket(&cf->socket);
if (status < 0) {
dev_err(device, "pcmcia_register_socket failed\n");
goto fail3;
}
dev_info(device, "at mem 0x%lx io 0x%llx irq %d\n",
cf->mem_phys, io.start, cf->irq);
cf->active = 1;
electra_cf_timer(&cf->timer);
return 0;
fail3:
release_region(cf->io_base, cf->io_size);
fail2:
release_mem_region(cf->mem_phys, cf->mem_size);
fail1:
if (cf->irq)
free_irq(cf->irq, cf);
if (cf->io_virt)
__iounmap_at(cf->io_virt, cf->io_size);
if (cf->mem_base)
iounmap(cf->mem_base);
if (cf->gpio_base)
iounmap(cf->gpio_base);
if (area)
device_init_wakeup(&ofdev->dev, 0);
kfree(cf);
return status;
}
static int electra_cf_remove(struct platform_device *ofdev)
{
struct device *device = &ofdev->dev;
struct electra_cf_socket *cf;
cf = dev_get_drvdata(device);
cf->active = 0;
pcmcia_unregister_socket(&cf->socket);
free_irq(cf->irq, cf);
del_timer_sync(&cf->timer);
__iounmap_at(cf->io_virt, cf->io_size);
iounmap(cf->mem_base);
iounmap(cf->gpio_base);
release_mem_region(cf->mem_phys, cf->mem_size);
release_region(cf->io_base, cf->io_size);
kfree(cf);
return 0;
}
static const struct of_device_id electra_cf_match[] = {
{
.compatible = "electra-cf",
},
{},
};
MODULE_DEVICE_TABLE(of, electra_cf_match);
static struct platform_driver electra_cf_driver = {
.driver = {
.name = driver_name,
.of_match_table = electra_cf_match,
},
.probe = electra_cf_probe,
.remove = electra_cf_remove,
};
module_platform_driver(electra_cf_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Olof Johansson <olof@lixom.net>");
MODULE_DESCRIPTION("PA Semi Electra CF driver");
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