Revision d7831a0bdf06b9f722b947bb0c205ff7d77cebd8 authored by Richard Kennedy on 30 June 2009, 18:41:35 UTC, committed by Linus Torvalds on 01 July 2009, 01:56:01 UTC
balance_dirty_pages can overreact and move all of the dirty pages to writeback unnecessarily. balance_dirty_pages makes its decision to throttle based on the number of dirty plus writeback pages that are over the calculated limit,so it will continue to move pages even when there are plenty of pages in writeback and less than the threshold still dirty. This allows it to overshoot its limits and move all the dirty pages to writeback while waiting for the drives to catch up and empty the writeback list. A simple fio test easily demonstrates this problem. fio --name=f1 --directory=/disk1 --size=2G -rw=write --name=f2 --directory=/disk2 --size=1G --rw=write --startdelay=10 This is the simplest fix I could find, but I'm not entirely sure that it alone will be enough for all cases. But it certainly is an improvement on my desktop machine writing to 2 disks. Do we need something more for machines with large arrays where bdi_threshold * number_of_drives is greater than the dirty_ratio ? Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent df279ca
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/slab.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/system.h>
#include <asm/addrspace.h>
#include <pcmcia/cs_types.h>
#include <pcmcia/ss.h>
#include <pcmcia/cs.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
#ifdef CONFIG_PCMCIA_DEBUG
static int m32r_pcc_debug;
module_param(m32r_pcc_debug, int, 0644);
#define debug(lvl, fmt, arg...) do { \
if (m32r_pcc_debug > (lvl)) \
printk(KERN_DEBUG "m32r_pcc: " fmt , ## arg); \
} while (0)
#else
#define debug(n, args...) do { } while (0)
#endif
/* 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 void add_pcc_socket(ulong base, int irq, ulong mapaddr,
unsigned int ioaddr)
{
pcc_socket_t *t = &socket[pcc_sockets];
/* 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 */
request_irq(irq, pcc_interrupt, 0, "m32r-pcc", pcc_interrupt);
pcc_sockets++;
return;
}
/*====================================================================*/
static irqreturn_t pcc_interrupt(int irq, void *dev)
{
int i, j, irc;
u_int events, active;
int handled = 0;
debug(4, "m32r: 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;
debug(2, "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;
debug(2, " 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");
debug(4, "m32r-pcc: interrupt done\n");
return IRQ_RETVAL(handled);
} /* pcc_interrupt */
static void pcc_interrupt_wrapper(u_long data)
{
pcc_interrupt(0, NULL);
init_timer(&poll_timer);
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;
debug(3, "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;
debug(3, "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) {
debug(3, ":RESET\n");
reg |= PCCSIGCR_CRST;
}
if (state->flags & SS_OUTPUT_ENA){
debug(3, ":OUTPUT_ENA\n");
/* bit clear */
} else {
reg |= PCCSIGCR_SEN;
}
pcc_set(sock,PCCSIGCR,reg);
#ifdef CONFIG_PCMCIA_DEBUG
if(state->flags & SS_IOCARD){
debug(3, ":IOCARD");
}
if (state->flags & SS_PWR_AUTO) {
debug(3, ":PWR_AUTO");
}
if (state->csc_mask & SS_DETECT)
debug(3, ":csc-SS_DETECT");
if (state->flags & SS_IOCARD) {
if (state->csc_mask & SS_STSCHG)
debug(3, ":STSCHG");
} else {
if (state->csc_mask & SS_BATDEAD)
debug(3, ":BATDEAD");
if (state->csc_mask & SS_BATWARN)
debug(3, ":BATWARN");
if (state->csc_mask & SS_READY)
debug(3, ":READY");
}
debug(3, "\n");
#endif
return 0;
} /* _set_socket */
/*====================================================================*/
static int _pcc_set_io_map(u_short sock, struct pccard_io_map *io)
{
u_char map;
debug(3, "m32r-pcc: SetIOMap(%d, %d, %#2.2x, %d ns, "
"%#x-%#x)\n", sock, io->map, io->flags,
io->speed, io->start, 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
debug(3, "m32r-pcc: SetMemMap(%d, %d, %#2.2x, %d ns, "
"%#lx, %#x)\n", sock, map, mem->flags,
mem->speed, 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)
{
debug(4, "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 int pcc_drv_pcmcia_suspend(struct platform_device *dev,
pm_message_t state)
{
return pcmcia_socket_dev_suspend(&dev->dev, state);
}
static int pcc_drv_pcmcia_resume(struct platform_device *dev)
{
return pcmcia_socket_dev_resume(&dev->dev);
}
/*====================================================================*/
static struct platform_driver pcc_driver = {
.driver = {
.name = "pcc",
.owner = THIS_MODULE,
},
.suspend = pcc_drv_pcmcia_suspend,
.resume = pcc_drv_pcmcia_resume,
};
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){
platform_driver_unregister(&pcc_driver);
return ret;
}
printk(KERN_INFO "m32r PCC probe:\n");
pcc_sockets = 0;
add_pcc_socket(M32R_PCC0_BASE, PCC0_IRQ, M32R_PCC0_MAPBASE, 0x1000);
#ifdef CONFIG_M32RPCC_SLOT2
add_pcc_socket(M32R_PCC1_BASE, PCC1_IRQ, M32R_PCC1_MAPBASE, 0x2000);
#endif
if (pcc_sockets == 0) {
printk("socket is not found.\n");
platform_device_unregister(&pcc_device);
platform_driver_unregister(&pcc_driver);
return -ENODEV;
}
/* 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;
#if 0 /* driver model ordering issue */
class_device_create_file(&socket[i].socket.dev,
&class_device_attr_info);
class_device_create_file(&socket[i].socket.dev,
&class_device_attr_exca);
#endif
}
/* Finally, schedule a polling interrupt */
if (poll_interval != 0) {
poll_timer.function = pcc_interrupt_wrapper;
poll_timer.data = 0;
init_timer(&poll_timer);
poll_timer.expires = jiffies + poll_interval;
add_timer(&poll_timer);
}
return 0;
} /* 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");
/*====================================================================*/
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