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
vrc4173_cardu.c
/*
* FILE NAME
* drivers/pcmcia/vrc4173_cardu.c
*
* BRIEF MODULE DESCRIPTION
* NEC VRC4173 CARDU driver for Socket Services
* (This device doesn't support CardBus. it is supporting only 16bit PC Card.)
*
* Copyright 2002,2003 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* 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 SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/io.h>
#include <pcmcia/ss.h>
#include "vrc4173_cardu.h"
MODULE_DESCRIPTION("NEC VRC4173 CARDU driver for Socket Services");
MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>");
MODULE_LICENSE("GPL");
static int vrc4173_cardu_slots;
static vrc4173_socket_t cardu_sockets[CARDU_MAX_SOCKETS];
extern struct socket_info_t *pcmcia_register_socket (int slot,
struct pccard_operations *vtable,
int use_bus_pm);
extern void pcmcia_unregister_socket(struct socket_info_t *s);
static inline uint8_t exca_readb(vrc4173_socket_t *socket, uint16_t offset)
{
return readb(socket->base + EXCA_REGS_BASE + offset);
}
static inline uint16_t exca_readw(vrc4173_socket_t *socket, uint16_t offset)
{
uint16_t val;
val = readb(socket->base + EXCA_REGS_BASE + offset);
val |= (u16)readb(socket->base + EXCA_REGS_BASE + offset + 1) << 8;
return val;
}
static inline void exca_writeb(vrc4173_socket_t *socket, uint16_t offset, uint8_t val)
{
writeb(val, socket->base + EXCA_REGS_BASE + offset);
}
static inline void exca_writew(vrc4173_socket_t *socket, uint8_t offset, uint16_t val)
{
writeb((u8)val, socket->base + EXCA_REGS_BASE + offset);
writeb((u8)(val >> 8), socket->base + EXCA_REGS_BASE + offset + 1);
}
static inline uint32_t cardbus_socket_readl(vrc4173_socket_t *socket, u16 offset)
{
return readl(socket->base + CARDBUS_SOCKET_REGS_BASE + offset);
}
static inline void cardbus_socket_writel(vrc4173_socket_t *socket, u16 offset, uint32_t val)
{
writel(val, socket->base + CARDBUS_SOCKET_REGS_BASE + offset);
}
static void cardu_pciregs_init(struct pci_dev *dev)
{
u32 syscnt;
u16 brgcnt;
u8 devcnt;
pci_write_config_dword(dev, 0x1c, 0x10000000);
pci_write_config_dword(dev, 0x20, 0x17fff000);
pci_write_config_dword(dev, 0x2c, 0);
pci_write_config_dword(dev, 0x30, 0xfffc);
pci_read_config_word(dev, BRGCNT, &brgcnt);
brgcnt &= ~IREQ_INT;
pci_write_config_word(dev, BRGCNT, brgcnt);
pci_read_config_dword(dev, SYSCNT, &syscnt);
syscnt &= ~(BAD_VCC_REQ_DISB|PCPCI_EN|CH_ASSIGN_MASK|SUB_ID_WR_EN|PCI_CLK_RIN);
syscnt |= (CH_ASSIGN_NODMA|ASYN_INT_MODE);
pci_write_config_dword(dev, SYSCNT, syscnt);
pci_read_config_byte(dev, DEVCNT, &devcnt);
devcnt &= ~(ZOOM_VIDEO_EN|SR_PCI_INT_SEL_MASK|PCI_INT_MODE|IRQ_MODE);
devcnt |= (SR_PCI_INT_SEL_NONE|IFG);
pci_write_config_byte(dev, DEVCNT, devcnt);
pci_write_config_byte(dev, CHIPCNT, S_PREF_DISB);
pci_write_config_byte(dev, SERRDIS, 0);
}
static int cardu_init(unsigned int slot)
{
vrc4173_socket_t *socket = &cardu_sockets[slot];
cardu_pciregs_init(socket->dev);
/* CARD_SC bits are cleared by reading CARD_SC. */
exca_writeb(socket, GLO_CNT, 0);
socket->cap.features |= SS_CAP_PCCARD | SS_CAP_PAGE_REGS;
socket->cap.irq_mask = 0;
socket->cap.map_size = 0x1000;
socket->cap.pci_irq = socket->dev->irq;
socket->events = 0;
spin_lock_init(socket->event_lock);
/* Enable PC Card status interrupts */
exca_writeb(socket, CARD_SCI, CARD_DT_EN|RDY_EN|BAT_WAR_EN|BAT_DEAD_EN);
return 0;
}
static int cardu_register_callback(unsigned int sock,
void (*handler)(void *, unsigned int),
void * info)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
socket->handler = handler;
socket->info = info;
return 0;
}
static int cardu_inquire_socket(unsigned int sock, socket_cap_t *cap)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
*cap = socket->cap;
return 0;
}
static int cardu_get_status(unsigned int sock, u_int *value)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint32_t state;
uint8_t status;
u_int val = 0;
status = exca_readb(socket, IF_STATUS);
if (status & CARD_PWR) val |= SS_POWERON;
if (status & READY) val |= SS_READY;
if (status & CARD_WP) val |= SS_WRPROT;
if ((status & (CARD_DETECT1|CARD_DETECT2)) == (CARD_DETECT1|CARD_DETECT2))
val |= SS_DETECT;
if (exca_readb(socket, INT_GEN_CNT) & CARD_TYPE_IO) {
if (status & STSCHG) val |= SS_STSCHG;
} else {
status &= BV_DETECT_MASK;
if (status != BV_DETECT_GOOD) {
if (status == BV_DETECT_WARN) val |= SS_BATWARN;
else val |= SS_BATDEAD;
}
}
state = cardbus_socket_readl(socket, SKT_PRE_STATE);
if (state & VOL_3V_CARD_DT) val |= SS_3VCARD;
if (state & VOL_XV_CARD_DT) val |= SS_XVCARD;
if (state & CB_CARD_DT) val |= SS_CARDBUS;
if (!(state &
(VOL_YV_CARD_DT|VOL_XV_CARD_DT|VOL_3V_CARD_DT|VOL_5V_CARD_DT|CCD20|CCD10)))
val |= SS_PENDING;
*value = val;
return 0;
}
static inline uint8_t set_Vcc_value(u_char Vcc)
{
switch (Vcc) {
case 33:
return VCC_3V;
case 50:
return VCC_5V;
}
return VCC_0V;
}
static inline uint8_t set_Vpp_value(u_char Vpp)
{
switch (Vpp) {
case 33:
case 50:
return VPP_VCC;
case 120:
return VPP_12V;
}
return VPP_0V;
}
static int cardu_set_socket(unsigned int sock, socket_state_t *state)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint8_t val;
if (((state->Vpp == 33) || (state->Vpp == 50)) && (state->Vpp != state->Vcc))
return -EINVAL;
val = set_Vcc_value(state->Vcc);
val |= set_Vpp_value(state->Vpp);
if (state->flags & SS_OUTPUT_ENA) val |= CARD_OUT_EN;
exca_writeb(socket, PWR_CNT, val);
val = exca_readb(socket, INT_GEN_CNT) & CARD_REST0;
if (state->flags & SS_RESET) val &= ~CARD_REST0;
else val |= CARD_REST0;
if (state->flags & SS_IOCARD) val |= CARD_TYPE_IO;
exca_writeb(socket, INT_GEN_CNT, val);
return 0;
}
static int cardu_get_io_map(unsigned int sock, struct pccard_io_map *io)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint8_t ioctl, window;
u_char map;
map = io->map;
if (map > 1)
return -EINVAL;
io->start = exca_readw(socket, IO_WIN_SA(map));
io->stop = exca_readw(socket, IO_WIN_EA(map));
ioctl = exca_readb(socket, IO_WIN_CNT);
window = exca_readb(socket, ADR_WIN_EN);
io->flags = (window & IO_WIN_EN(map)) ? MAP_ACTIVE : 0;
if (ioctl & IO_WIN_DATA_AUTOSZ(map))
io->flags |= MAP_AUTOSZ;
else if (ioctl & IO_WIN_DATA_16BIT(map))
io->flags |= MAP_16BIT;
return 0;
}
static int cardu_set_io_map(unsigned int sock, struct pccard_io_map *io)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint16_t ioctl;
uint8_t window, enable;
u_char map;
map = io->map;
if (map > 1)
return -EINVAL;
window = exca_readb(socket, ADR_WIN_EN);
enable = IO_WIN_EN(map);
if (window & enable) {
window &= ~enable;
exca_writeb(socket, ADR_WIN_EN, window);
}
exca_writew(socket, IO_WIN_SA(map), io->start);
exca_writew(socket, IO_WIN_EA(map), io->stop);
ioctl = exca_readb(socket, IO_WIN_CNT) & ~IO_WIN_CNT_MASK(map);
if (io->flags & MAP_AUTOSZ) ioctl |= IO_WIN_DATA_AUTOSZ(map);
else if (io->flags & MAP_16BIT) ioctl |= IO_WIN_DATA_16BIT(map);
exca_writeb(socket, IO_WIN_CNT, ioctl);
if (io->flags & MAP_ACTIVE)
exca_writeb(socket, ADR_WIN_EN, window | enable);
return 0;
}
static int cardu_get_mem_map(unsigned int sock, struct pccard_mem_map *mem)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint32_t start, stop, offset, page;
uint8_t window;
u_char map;
map = mem->map;
if (map > 4)
return -EINVAL;
window = exca_readb(socket, ADR_WIN_EN);
mem->flags = (window & MEM_WIN_EN(map)) ? MAP_ACTIVE : 0;
start = exca_readw(socket, MEM_WIN_SA(map));
mem->flags |= (start & MEM_WIN_DSIZE) ? MAP_16BIT : 0;
start = (start & 0x0fff) << 12;
stop = exca_readw(socket, MEM_WIN_EA(map));
stop = ((stop & 0x0fff) << 12) + 0x0fff;
offset = exca_readw(socket, MEM_WIN_OA(map));
mem->flags |= (offset & MEM_WIN_WP) ? MAP_WRPROT : 0;
mem->flags |= (offset & MEM_WIN_REGSET) ? MAP_ATTRIB : 0;
offset = ((offset & 0x3fff) << 12) + start;
mem->card_start = offset & 0x03ffffff;
page = exca_readb(socket, MEM_WIN_SAU(map)) << 24;
mem->sys_start = start + page;
mem->sys_stop = start + page;
return 0;
}
static int cardu_set_mem_map(unsigned int sock, struct pccard_mem_map *mem)
{
vrc4173_socket_t *socket = &cardu_sockets[sock];
uint16_t value;
uint8_t window, enable;
u_long sys_start, sys_stop, card_start;
u_char map;
map = mem->map;
sys_start = mem->sys_start;
sys_stop = mem->sys_stop;
card_start = mem->card_start;
if (map > 4 || sys_start > sys_stop || ((sys_start ^ sys_stop) >> 24) ||
(card_start >> 26))
return -EINVAL;
window = exca_readb(socket, ADR_WIN_EN);
enable = MEM_WIN_EN(map);
if (window & enable) {
window &= ~enable;
exca_writeb(socket, ADR_WIN_EN, window);
}
exca_writeb(socket, MEM_WIN_SAU(map), sys_start >> 24);
value = (sys_start >> 12) & 0x0fff;
if (mem->flags & MAP_16BIT) value |= MEM_WIN_DSIZE;
exca_writew(socket, MEM_WIN_SA(map), value);
value = (sys_stop >> 12) & 0x0fff;
exca_writew(socket, MEM_WIN_EA(map), value);
value = ((card_start - sys_start) >> 12) & 0x3fff;
if (mem->flags & MAP_WRPROT) value |= MEM_WIN_WP;
if (mem->flags & MAP_ATTRIB) value |= MEM_WIN_REGSET;
exca_writew(socket, MEM_WIN_OA(map), value);
if (mem->flags & MAP_ACTIVE)
exca_writeb(socket, ADR_WIN_EN, window | enable);
return 0;
}
static void cardu_proc_setup(unsigned int sock, struct proc_dir_entry *base)
{
}
static struct pccard_operations cardu_operations = {
.init = cardu_init,
.register_callback = cardu_register_callback,
.inquire_socket = cardu_inquire_socket,
.get_status = cardu_get_status,
.set_socket = cardu_set_socket,
.get_io_map = cardu_get_io_map,
.set_io_map = cardu_set_io_map,
.get_mem_map = cardu_get_mem_map,
.set_mem_map = cardu_set_mem_map,
.proc_setup = cardu_proc_setup,
};
static void cardu_bh(void *data)
{
vrc4173_socket_t *socket = (vrc4173_socket_t *)data;
uint16_t events;
spin_lock_irq(&socket->event_lock);
events = socket->events;
socket->events = 0;
spin_unlock_irq(&socket->event_lock);
if (socket->handler)
socket->handler(socket->info, events);
}
static uint16_t get_events(vrc4173_socket_t *socket)
{
uint16_t events = 0;
uint8_t csc, status;
status = exca_readb(socket, IF_STATUS);
csc = exca_readb(socket, CARD_SC);
if ((csc & CARD_DT_CHG) &&
((status & (CARD_DETECT1|CARD_DETECT2)) == (CARD_DETECT1|CARD_DETECT2)))
events |= SS_DETECT;
if ((csc & RDY_CHG) && (status & READY))
events |= SS_READY;
if (exca_readb(socket, INT_GEN_CNT) & CARD_TYPE_IO) {
if ((csc & BAT_DEAD_ST_CHG) && (status & STSCHG))
events |= SS_STSCHG;
} else {
if (csc & (BAT_WAR_CHG|BAT_DEAD_ST_CHG)) {
if ((status & BV_DETECT_MASK) != BV_DETECT_GOOD) {
if (status == BV_DETECT_WARN) events |= SS_BATWARN;
else events |= SS_BATDEAD;
}
}
}
return events;
}
static void cardu_interrupt(int irq, void *dev_id)
{
vrc4173_socket_t *socket = (vrc4173_socket_t *)dev_id;
uint16_t events;
INIT_WORK(&socket->tq_work, cardu_bh, socket);
events = get_events(socket);
if (events) {
spin_lock(&socket->event_lock);
socket->events |= events;
spin_unlock(&socket->event_lock);
schedule_work(&socket->tq_work);
}
}
static int __devinit vrc4173_cardu_probe(struct pci_dev *dev,
const struct pci_device_id *ent)
{
vrc4173_socket_t *socket;
unsigned long start, len, flags;
int slot, err;
slot = vrc4173_cardu_slots++;
socket = &cardu_sockets[slot];
if (socket->noprobe != 0)
return -EBUSY;
sprintf(socket->name, "NEC VRC4173 CARDU%1d", slot+1);
if ((err = pci_enable_device(dev)) < 0)
return err;
start = pci_resource_start(dev, 0);
if (start == 0)
return -ENODEV;
len = pci_resource_len(dev, 0);
if (len == 0)
return -ENODEV;
if (((flags = pci_resource_flags(dev, 0)) & IORESOURCE_MEM) == 0)
return -EBUSY;
if ((err = pci_request_regions(dev, socket->name)) < 0)
return err;
socket->base = ioremap(start, len);
if (socket->base == NULL)
return -ENODEV;
socket->dev = dev;
socket->pcmcia_socket = pcmcia_register_socket(slot, &cardu_operations, 1);
if (socket->pcmcia_socket == NULL) {
iounmap(socket->base);
socket->base = NULL;
return -ENOMEM;
}
if (request_irq(dev->irq, cardu_interrupt, IRQF_SHARED, socket->name, socket) < 0) {
pcmcia_unregister_socket(socket->pcmcia_socket);
socket->pcmcia_socket = NULL;
iounmap(socket->base);
socket->base = NULL;
return -EBUSY;
}
printk(KERN_INFO "%s at %#08lx, IRQ %d\n", socket->name, start, dev->irq);
return 0;
}
static int __devinit vrc4173_cardu_setup(char *options)
{
if (options == NULL || *options == '\0')
return 1;
if (strncmp(options, "cardu1:", 7) == 0) {
options += 7;
if (*options != '\0') {
if (strncmp(options, "noprobe", 7) == 0) {
cardu_sockets[CARDU1].noprobe = 1;
options += 7;
}
if (*options != ',')
return 1;
} else
return 1;
}
if (strncmp(options, "cardu2:", 7) == 0) {
options += 7;
if ((*options != '\0') && (strncmp(options, "noprobe", 7) == 0))
cardu_sockets[CARDU2].noprobe = 1;
}
return 1;
}
__setup("vrc4173_cardu=", vrc4173_cardu_setup);
static struct pci_device_id vrc4173_cardu_id_table[] __devinitdata = {
{ .vendor = PCI_VENDOR_ID_NEC,
.device = PCI_DEVICE_ID_NEC_NAPCCARD,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID, },
{0, }
};
static struct pci_driver vrc4173_cardu_driver = {
.name = "NEC VRC4173 CARDU",
.probe = vrc4173_cardu_probe,
.id_table = vrc4173_cardu_id_table,
};
static int __devinit vrc4173_cardu_init(void)
{
vrc4173_cardu_slots = 0;
return pci_register_driver(&vrc4173_cardu_driver);
}
static void __devexit vrc4173_cardu_exit(void)
{
pci_unregister_driver(&vrc4173_cardu_driver);
}
module_init(vrc4173_cardu_init);
module_exit(vrc4173_cardu_exit);
MODULE_DEVICE_TABLE(pci, vrc4173_cardu_id_table);
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