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
m32r_pcc.c
/*
* drivers/pcmcia/m32r_pcc.c
*
* Device driver for the PCMCIA functionality of M32R.
*
* Copyright (c) 2001, 2002, 2003, 2004
* Hiroyuki Kondo, Naoto Sugai, Hayato Fujiwara
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/addrspace.h>
#include <pcmcia/ss.h>
/* XXX: should be moved into asm/irq.h */
#define PCC0_IRQ 24
#define PCC1_IRQ 25
#include "m32r_pcc.h"
#define CHAOS_PCC_DEBUG
#ifdef CHAOS_PCC_DEBUG
static volatile u_short dummy_readbuf;
#endif
#define PCC_DEBUG_DBEX
/* Poll status interval -- 0 means default to interrupt */
static int poll_interval = 0;
typedef enum pcc_space { as_none = 0, as_comm, as_attr, as_io } pcc_as_t;
typedef struct pcc_socket {
u_short type, flags;
struct pcmcia_socket socket;
unsigned int number;
unsigned int ioaddr;
u_long mapaddr;
u_long base; /* PCC register base */
u_char cs_irq, intr;
pccard_io_map io_map[MAX_IO_WIN];
pccard_mem_map mem_map[MAX_WIN];
u_char io_win;
u_char mem_win;
pcc_as_t current_space;
u_char last_iodbex;
#ifdef CHAOS_PCC_DEBUG
u_char last_iosize;
#endif
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc;
#endif
} pcc_socket_t;
static int pcc_sockets = 0;
static pcc_socket_t socket[M32R_MAX_PCC] = {
{ 0, }, /* ... */
};
/*====================================================================*/
static unsigned int pcc_get(u_short, unsigned int);
static void pcc_set(u_short, unsigned int , unsigned int );
static DEFINE_SPINLOCK(pcc_lock);
void pcc_iorw(int sock, unsigned long port, void *buf, size_t size, size_t nmemb, int wr, int flag)
{
u_long addr;
u_long flags;
int need_ex;
#ifdef PCC_DEBUG_DBEX
int _dbex;
#endif
pcc_socket_t *t = &socket[sock];
#ifdef CHAOS_PCC_DEBUG
int map_changed = 0;
#endif
/* Need lock ? */
spin_lock_irqsave(&pcc_lock, flags);
/*
* Check if need dbex
*/
need_ex = (size > 1 && flag == 0) ? PCMOD_DBEX : 0;
#ifdef PCC_DEBUG_DBEX
_dbex = need_ex;
need_ex = 0;
#endif
/*
* calculate access address
*/
addr = t->mapaddr + port - t->ioaddr + KSEG1; /* XXX */
/*
* Check current mapping
*/
if (t->current_space != as_io || t->last_iodbex != need_ex) {
u_long cbsz;
/*
* Disable first
*/
pcc_set(sock, PCCR, 0);
/*
* Set mode and io address
*/
cbsz = (t->flags & MAP_16BIT) ? 0 : PCMOD_CBSZ;
pcc_set(sock, PCMOD, PCMOD_AS_IO | cbsz | need_ex);
pcc_set(sock, PCADR, addr & 0x1ff00000);
/*
* Enable and read it
*/
pcc_set(sock, PCCR, 1);
#ifdef CHAOS_PCC_DEBUG
#if 0
map_changed = (t->current_space == as_attr && size == 2); /* XXX */
#else
map_changed = 1;
#endif
#endif
t->current_space = as_io;
}
/*
* access to IO space
*/
if (size == 1) {
/* Byte */
unsigned char *bp = (unsigned char *)buf;
#ifdef CHAOS_DEBUG
if (map_changed) {
dummy_readbuf = readb(addr);
}
#endif
if (wr) {
/* write Byte */
while (nmemb--) {
writeb(*bp++, addr);
}
} else {
/* read Byte */
while (nmemb--) {
*bp++ = readb(addr);
}
}
} else {
/* Word */
unsigned short *bp = (unsigned short *)buf;
#ifdef CHAOS_PCC_DEBUG
if (map_changed) {
dummy_readbuf = readw(addr);
}
#endif
if (wr) {
/* write Word */
while (nmemb--) {
#ifdef PCC_DEBUG_DBEX
if (_dbex) {
unsigned char *cp = (unsigned char *)bp;
unsigned short tmp;
tmp = cp[1] << 8 | cp[0];
writew(tmp, addr);
bp++;
} else
#endif
writew(*bp++, addr);
}
} else {
/* read Word */
while (nmemb--) {
#ifdef PCC_DEBUG_DBEX
if (_dbex) {
unsigned char *cp = (unsigned char *)bp;
unsigned short tmp;
tmp = readw(addr);
cp[0] = tmp & 0xff;
cp[1] = (tmp >> 8) & 0xff;
bp++;
} else
#endif
*bp++ = readw(addr);
}
}
}
#if 1
/* addr is no longer used */
if ((addr = pcc_get(sock, PCIRC)) & PCIRC_BWERR) {
printk("m32r_pcc: BWERR detected : port 0x%04lx : iosize %dbit\n",
port, size * 8);
pcc_set(sock, PCIRC, addr);
}
#endif
/*
* save state
*/
t->last_iosize = size;
t->last_iodbex = need_ex;
/* Need lock ? */
spin_unlock_irqrestore(&pcc_lock,flags);
return;
}
void pcc_ioread(int sock, unsigned long port, void *buf, size_t size, size_t nmemb, int flag) {
pcc_iorw(sock, port, buf, size, nmemb, 0, flag);
}
void pcc_iowrite(int sock, unsigned long port, void *buf, size_t size, size_t nmemb, int flag) {
pcc_iorw(sock, port, buf, size, nmemb, 1, flag);
}
/*====================================================================*/
#define IS_REGISTERED 0x2000
#define IS_ALIVE 0x8000
typedef struct pcc_t {
char *name;
u_short flags;
} pcc_t;
static pcc_t pcc[] = {
{ "xnux2", 0 }, { "xnux2", 0 },
};
static irqreturn_t pcc_interrupt(int, void *);
/*====================================================================*/
static struct timer_list poll_timer;
static unsigned int pcc_get(u_short sock, unsigned int reg)
{
return inl(socket[sock].base + reg);
}
static void pcc_set(u_short sock, unsigned int reg, unsigned int data)
{
outl(data, socket[sock].base + reg);
}
/*======================================================================
See if a card is present, powered up, in IO mode, and already
bound to a (non PC Card) Linux driver. We leave these alone.
We make an exception for cards that seem to be serial devices.
======================================================================*/
static int __init is_alive(u_short sock)
{
unsigned int stat;
unsigned int f;
stat = pcc_get(sock, PCIRC);
f = (stat & (PCIRC_CDIN1 | PCIRC_CDIN2)) >> 16;
if(!f){
printk("m32r_pcc: No Card is detected at socket %d : stat = 0x%08x\n",stat,sock);
return 0;
}
if(f!=3)
printk("m32r_pcc: Insertion fail (%.8x) at socket %d\n",stat,sock);
else
printk("m32r_pcc: Card is Inserted at socket %d(%.8x)\n",sock,stat);
return 0;
}
static int add_pcc_socket(ulong base, int irq, ulong mapaddr,
unsigned int ioaddr)
{
pcc_socket_t *t = &socket[pcc_sockets];
int err;
/* add sockets */
t->ioaddr = ioaddr;
t->mapaddr = mapaddr;
t->base = base;
#ifdef CHAOS_PCC_DEBUG
t->flags = MAP_16BIT;
#else
t->flags = 0;
#endif
if (is_alive(pcc_sockets))
t->flags |= IS_ALIVE;
/* add pcc */
if (t->base > 0) {
request_region(t->base, 0x20, "m32r-pcc");
}
printk(KERN_INFO " %s ", pcc[pcc_sockets].name);
printk("pcc at 0x%08lx\n", t->base);
/* Update socket interrupt information, capabilities */
t->socket.features |= (SS_CAP_PCCARD | SS_CAP_STATIC_MAP);
t->socket.map_size = M32R_PCC_MAPSIZE;
t->socket.io_offset = ioaddr; /* use for io access offset */
t->socket.irq_mask = 0;
t->socket.pci_irq = 2 + pcc_sockets; /* XXX */
err = request_irq(irq, pcc_interrupt, 0, "m32r-pcc", pcc_interrupt);
if (err) {
if (t->base > 0)
release_region(t->base, 0x20);
return err;
}
pcc_sockets++;
return 0;
}
/*====================================================================*/
static irqreturn_t pcc_interrupt(int irq, void *dev)
{
int i, j, irc;
u_int events, active;
int handled = 0;
pr_debug("m32r_pcc: pcc_interrupt(%d)\n", irq);
for (j = 0; j < 20; j++) {
active = 0;
for (i = 0; i < pcc_sockets; i++) {
if ((socket[i].cs_irq != irq) &&
(socket[i].socket.pci_irq != irq))
continue;
handled = 1;
irc = pcc_get(i, PCIRC);
irc >>=16;
pr_debug("m32r_pcc: interrupt: socket %d pcirc 0x%02x ",
i, irc);
if (!irc)
continue;
events = (irc) ? SS_DETECT : 0;
events |= (pcc_get(i,PCCR) & PCCR_PCEN) ? SS_READY : 0;
pr_debug("m32r_pcc: event 0x%02x\n", events);
if (events)
pcmcia_parse_events(&socket[i].socket, events);
active |= events;
active = 0;
}
if (!active) break;
}
if (j == 20)
printk(KERN_NOTICE "m32r-pcc: infinite loop in interrupt handler\n");
pr_debug("m32r_pcc: interrupt done\n");
return IRQ_RETVAL(handled);
} /* pcc_interrupt */
static void pcc_interrupt_wrapper(struct timer_list *unused)
{
pcc_interrupt(0, NULL);
poll_timer.expires = jiffies + poll_interval;
add_timer(&poll_timer);
}
/*====================================================================*/
static int _pcc_get_status(u_short sock, u_int *value)
{
u_int status;
status = pcc_get(sock,PCIRC);
*value = ((status & PCIRC_CDIN1) && (status & PCIRC_CDIN2))
? SS_DETECT : 0;
status = pcc_get(sock,PCCR);
#if 0
*value |= (status & PCCR_PCEN) ? SS_READY : 0;
#else
*value |= SS_READY; /* XXX: always */
#endif
status = pcc_get(sock,PCCSIGCR);
*value |= (status & PCCSIGCR_VEN) ? SS_POWERON : 0;
pr_debug("m32r_pcc: GetStatus(%d) = %#4.4x\n", sock, *value);
return 0;
} /* _get_status */
/*====================================================================*/
static int _pcc_set_socket(u_short sock, socket_state_t *state)
{
u_long reg = 0;
pr_debug("m32r_pcc: SetSocket(%d, flags %#3.3x, Vcc %d, Vpp %d, "
"io_irq %d, csc_mask %#2.2x)", sock, state->flags,
state->Vcc, state->Vpp, state->io_irq, state->csc_mask);
if (state->Vcc) {
/*
* 5V only
*/
if (state->Vcc == 50) {
reg |= PCCSIGCR_VEN;
} else {
return -EINVAL;
}
}
if (state->flags & SS_RESET) {
pr_debug("m32r_pcc: :RESET\n");
reg |= PCCSIGCR_CRST;
}
if (state->flags & SS_OUTPUT_ENA){
pr_debug("m32r_pcc: :OUTPUT_ENA\n");
/* bit clear */
} else {
reg |= PCCSIGCR_SEN;
}
pcc_set(sock,PCCSIGCR,reg);
if(state->flags & SS_IOCARD){
pr_debug("m32r_pcc: :IOCARD");
}
if (state->flags & SS_PWR_AUTO) {
pr_debug("m32r_pcc: :PWR_AUTO");
}
if (state->csc_mask & SS_DETECT)
pr_debug("m32r_pcc: :csc-SS_DETECT");
if (state->flags & SS_IOCARD) {
if (state->csc_mask & SS_STSCHG)
pr_debug("m32r_pcc: :STSCHG");
} else {
if (state->csc_mask & SS_BATDEAD)
pr_debug("m32r_pcc: :BATDEAD");
if (state->csc_mask & SS_BATWARN)
pr_debug("m32r_pcc: :BATWARN");
if (state->csc_mask & SS_READY)
pr_debug("m32r_pcc: :READY");
}
pr_debug("m32r_pcc: \n");
return 0;
} /* _set_socket */
/*====================================================================*/
static int _pcc_set_io_map(u_short sock, struct pccard_io_map *io)
{
u_char map;
pr_debug("m32r_pcc: SetIOMap(%d, %d, %#2.2x, %d ns, "
"%#llx-%#llx)\n", sock, io->map, io->flags,
io->speed, (unsigned long long)io->start,
(unsigned long long)io->stop);
map = io->map;
return 0;
} /* _set_io_map */
/*====================================================================*/
static int _pcc_set_mem_map(u_short sock, struct pccard_mem_map *mem)
{
u_char map = mem->map;
u_long mode;
u_long addr;
pcc_socket_t *t = &socket[sock];
#ifdef CHAOS_PCC_DEBUG
#if 0
pcc_as_t last = t->current_space;
#endif
#endif
pr_debug("m32r_pcc: SetMemMap(%d, %d, %#2.2x, %d ns, "
"%#llx, %#x)\n", sock, map, mem->flags,
mem->speed, (unsigned long long)mem->static_start,
mem->card_start);
/*
* sanity check
*/
if ((map > MAX_WIN) || (mem->card_start > 0x3ffffff)){
return -EINVAL;
}
/*
* de-activate
*/
if ((mem->flags & MAP_ACTIVE) == 0) {
t->current_space = as_none;
return 0;
}
/*
* Disable first
*/
pcc_set(sock, PCCR, 0);
/*
* Set mode
*/
if (mem->flags & MAP_ATTRIB) {
mode = PCMOD_AS_ATTRIB | PCMOD_CBSZ;
t->current_space = as_attr;
} else {
mode = 0; /* common memory */
t->current_space = as_comm;
}
pcc_set(sock, PCMOD, mode);
/*
* Set address
*/
addr = t->mapaddr + (mem->card_start & M32R_PCC_MAPMASK);
pcc_set(sock, PCADR, addr);
mem->static_start = addr + mem->card_start;
/*
* Enable again
*/
pcc_set(sock, PCCR, 1);
#ifdef CHAOS_PCC_DEBUG
#if 0
if (last != as_attr) {
#else
if (1) {
#endif
dummy_readbuf = *(u_char *)(addr + KSEG1);
}
#endif
return 0;
} /* _set_mem_map */
#if 0 /* driver model ordering issue */
/*======================================================================
Routines for accessing socket information and register dumps via
/proc/bus/pccard/...
======================================================================*/
static ssize_t show_info(struct class_device *class_dev, char *buf)
{
pcc_socket_t *s = container_of(class_dev, struct pcc_socket,
socket.dev);
return sprintf(buf, "type: %s\nbase addr: 0x%08lx\n",
pcc[s->type].name, s->base);
}
static ssize_t show_exca(struct class_device *class_dev, char *buf)
{
/* FIXME */
return 0;
}
static CLASS_DEVICE_ATTR(info, S_IRUGO, show_info, NULL);
static CLASS_DEVICE_ATTR(exca, S_IRUGO, show_exca, NULL);
#endif
/*====================================================================*/
/* this is horribly ugly... proper locking needs to be done here at
* some time... */
#define LOCKED(x) do { \
int retval; \
unsigned long flags; \
spin_lock_irqsave(&pcc_lock, flags); \
retval = x; \
spin_unlock_irqrestore(&pcc_lock, flags); \
return retval; \
} while (0)
static int pcc_get_status(struct pcmcia_socket *s, u_int *value)
{
unsigned int sock = container_of(s, struct pcc_socket, socket)->number;
if (socket[sock].flags & IS_ALIVE) {
*value = 0;
return -EINVAL;
}
LOCKED(_pcc_get_status(sock, value));
}
static int pcc_set_socket(struct pcmcia_socket *s, socket_state_t *state)
{
unsigned int sock = container_of(s, struct pcc_socket, socket)->number;
if (socket[sock].flags & IS_ALIVE)
return -EINVAL;
LOCKED(_pcc_set_socket(sock, state));
}
static int pcc_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
unsigned int sock = container_of(s, struct pcc_socket, socket)->number;
if (socket[sock].flags & IS_ALIVE)
return -EINVAL;
LOCKED(_pcc_set_io_map(sock, io));
}
static int pcc_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *mem)
{
unsigned int sock = container_of(s, struct pcc_socket, socket)->number;
if (socket[sock].flags & IS_ALIVE)
return -EINVAL;
LOCKED(_pcc_set_mem_map(sock, mem));
}
static int pcc_init(struct pcmcia_socket *s)
{
pr_debug("m32r_pcc: init call\n");
return 0;
}
static struct pccard_operations pcc_operations = {
.init = pcc_init,
.get_status = pcc_get_status,
.set_socket = pcc_set_socket,
.set_io_map = pcc_set_io_map,
.set_mem_map = pcc_set_mem_map,
};
/*====================================================================*/
static struct platform_driver pcc_driver = {
.driver = {
.name = "pcc",
},
};
static struct platform_device pcc_device = {
.name = "pcc",
.id = 0,
};
/*====================================================================*/
static int __init init_m32r_pcc(void)
{
int i, ret;
ret = platform_driver_register(&pcc_driver);
if (ret)
return ret;
ret = platform_device_register(&pcc_device);
if (ret)
goto unreg_driv;
printk(KERN_INFO "m32r PCC probe:\n");
pcc_sockets = 0;
ret = add_pcc_socket(M32R_PCC0_BASE, PCC0_IRQ, M32R_PCC0_MAPBASE,
0x1000);
if (ret)
goto unreg_dev;
#ifdef CONFIG_M32RPCC_SLOT2
ret = add_pcc_socket(M32R_PCC1_BASE, PCC1_IRQ, M32R_PCC1_MAPBASE,
0x2000);
if (ret)
goto unreg_dev;
#endif
if (pcc_sockets == 0) {
printk("socket is not found.\n");
ret = -ENODEV;
goto unreg_dev;
}
/* Set up interrupt handler(s) */
for (i = 0 ; i < pcc_sockets ; i++) {
socket[i].socket.dev.parent = &pcc_device.dev;
socket[i].socket.ops = &pcc_operations;
socket[i].socket.resource_ops = &pccard_static_ops;
socket[i].socket.owner = THIS_MODULE;
socket[i].number = i;
ret = pcmcia_register_socket(&socket[i].socket);
if (!ret)
socket[i].flags |= IS_REGISTERED;
}
/* Finally, schedule a polling interrupt */
if (poll_interval != 0) {
timer_setup(&poll_timer, pcc_interrupt_wrapper, 0);
poll_timer.expires = jiffies + poll_interval;
add_timer(&poll_timer);
}
return 0;
unreg_dev:
platform_device_unregister(&pcc_device);
unreg_driv:
platform_driver_unregister(&pcc_driver);
return ret;
} /* init_m32r_pcc */
static void __exit exit_m32r_pcc(void)
{
int i;
for (i = 0; i < pcc_sockets; i++)
if (socket[i].flags & IS_REGISTERED)
pcmcia_unregister_socket(&socket[i].socket);
platform_device_unregister(&pcc_device);
if (poll_interval != 0)
del_timer_sync(&poll_timer);
platform_driver_unregister(&pcc_driver);
} /* exit_m32r_pcc */
module_init(init_m32r_pcc);
module_exit(exit_m32r_pcc);
MODULE_LICENSE("Dual MPL/GPL");
/*====================================================================*/
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...