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>
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ricoh.h
/*
* ricoh.h 1.9 1999/10/25 20:03:34
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License
* at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and
* limitations under the License.
*
* The initial developer of the original code is David A. Hinds
* <dahinds@users.sourceforge.net>. Portions created by David A. Hinds
* are Copyright (C) 1999 David A. Hinds. All Rights Reserved.
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License version 2 (the "GPL"), in which
* case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use
* your version of this file under the MPL, indicate your decision by
* deleting the provisions above and replace them with the notice and
* other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file
* under either the MPL or the GPL.
*/
#ifndef _LINUX_RICOH_H
#define _LINUX_RICOH_H
#define RF5C_MODE_CTL 0x1f /* Mode control */
#define RF5C_PWR_CTL 0x2f /* Mixed voltage control */
#define RF5C_CHIP_ID 0x3a /* Chip identification */
#define RF5C_MODE_CTL_3 0x3b /* Mode control 3 */
/* I/O window address offset */
#define RF5C_IO_OFF(w) (0x36+((w)<<1))
/* Flags for RF5C_MODE_CTL */
#define RF5C_MODE_ATA 0x01 /* ATA mode */
#define RF5C_MODE_LED_ENA 0x02 /* IRQ 12 is LED */
#define RF5C_MODE_CA21 0x04
#define RF5C_MODE_CA22 0x08
#define RF5C_MODE_CA23 0x10
#define RF5C_MODE_CA24 0x20
#define RF5C_MODE_CA25 0x40
#define RF5C_MODE_3STATE_BIT7 0x80
/* Flags for RF5C_PWR_CTL */
#define RF5C_PWR_VCC_3V 0x01
#define RF5C_PWR_IREQ_HIGH 0x02
#define RF5C_PWR_INPACK_ENA 0x04
#define RF5C_PWR_5V_DET 0x08
#define RF5C_PWR_TC_SEL 0x10 /* Terminal Count: irq 11 or 15 */
#define RF5C_PWR_DREQ_LOW 0x20
#define RF5C_PWR_DREQ_OFF 0x00 /* DREQ steering control */
#define RF5C_PWR_DREQ_INPACK 0x40
#define RF5C_PWR_DREQ_SPKR 0x80
#define RF5C_PWR_DREQ_IOIS16 0xc0
/* Values for RF5C_CHIP_ID */
#define RF5C_CHIP_RF5C296 0x32
#define RF5C_CHIP_RF5C396 0xb2
/* Flags for RF5C_MODE_CTL_3 */
#define RF5C_MCTL3_DISABLE 0x01 /* Disable PCMCIA interface */
#define RF5C_MCTL3_DMA_ENA 0x02
/* Register definitions for Ricoh PCI-to-CardBus bridges */
/* Extra bits in CB_BRIDGE_CONTROL */
#define RL5C46X_BCR_3E0_ENA 0x0800
#define RL5C46X_BCR_3E2_ENA 0x1000
/* Bridge Configuration Register */
#define RL5C4XX_CONFIG 0x80 /* 16 bit */
#define RL5C4XX_CONFIG_IO_1_MODE 0x0200
#define RL5C4XX_CONFIG_IO_0_MODE 0x0100
#define RL5C4XX_CONFIG_PREFETCH 0x0001
/* Misc Control Register */
#define RL5C4XX_MISC 0x0082 /* 16 bit */
#define RL5C4XX_MISC_HW_SUSPEND_ENA 0x0002
#define RL5C4XX_MISC_VCCEN_POL 0x0100
#define RL5C4XX_MISC_VPPEN_POL 0x0200
#define RL5C46X_MISC_SUSPEND 0x0001
#define RL5C46X_MISC_PWR_SAVE_2 0x0004
#define RL5C46X_MISC_IFACE_BUSY 0x0008
#define RL5C46X_MISC_B_LOCK 0x0010
#define RL5C46X_MISC_A_LOCK 0x0020
#define RL5C46X_MISC_PCI_LOCK 0x0040
#define RL5C47X_MISC_IFACE_BUSY 0x0004
#define RL5C47X_MISC_PCI_INT_MASK 0x0018
#define RL5C47X_MISC_PCI_INT_DIS 0x0020
#define RL5C47X_MISC_SUBSYS_WR 0x0040
#define RL5C47X_MISC_SRIRQ_ENA 0x0080
#define RL5C47X_MISC_5V_DISABLE 0x0400
#define RL5C47X_MISC_LED_POL 0x0800
/* 16-bit Interface Control Register */
#define RL5C4XX_16BIT_CTL 0x0084 /* 16 bit */
#define RL5C4XX_16CTL_IO_TIMING 0x0100
#define RL5C4XX_16CTL_MEM_TIMING 0x0200
#define RL5C46X_16CTL_LEVEL_1 0x0010
#define RL5C46X_16CTL_LEVEL_2 0x0020
/* 16-bit IO and memory timing registers */
#define RL5C4XX_16BIT_IO_0 0x0088 /* 16 bit */
#define RL5C4XX_16BIT_MEM_0 0x008a /* 16 bit */
#define RL5C4XX_SETUP_MASK 0x0007
#define RL5C4XX_SETUP_SHIFT 0
#define RL5C4XX_CMD_MASK 0x01f0
#define RL5C4XX_CMD_SHIFT 4
#define RL5C4XX_HOLD_MASK 0x1c00
#define RL5C4XX_HOLD_SHIFT 10
#define RL5C4XX_MISC_CONTROL 0x2F /* 8 bit */
#define RL5C4XX_ZV_ENABLE 0x08
#ifdef __YENTA_H
#define rl_misc(socket) ((socket)->private[0])
#define rl_ctl(socket) ((socket)->private[1])
#define rl_io(socket) ((socket)->private[2])
#define rl_mem(socket) ((socket)->private[3])
#define rl_config(socket) ((socket)->private[4])
static void ricoh_zoom_video(struct pcmcia_socket *sock, int onoff)
{
u8 reg;
struct yenta_socket *socket = container_of(sock, struct yenta_socket, socket);
reg = config_readb(socket, RL5C4XX_MISC_CONTROL);
if (onoff)
/* Zoom zoom, we will all go together, zoom zoom, zoom zoom */
reg |= RL5C4XX_ZV_ENABLE;
else
reg &= ~RL5C4XX_ZV_ENABLE;
config_writeb(socket, RL5C4XX_MISC_CONTROL, reg);
}
static void ricoh_set_zv(struct yenta_socket *socket)
{
if(socket->dev->vendor == PCI_VENDOR_ID_RICOH)
{
switch(socket->dev->device)
{
/* There may be more .. */
case PCI_DEVICE_ID_RICOH_RL5C478:
socket->socket.zoom_video = ricoh_zoom_video;
break;
}
}
}
static void ricoh_save_state(struct yenta_socket *socket)
{
rl_misc(socket) = config_readw(socket, RL5C4XX_MISC);
rl_ctl(socket) = config_readw(socket, RL5C4XX_16BIT_CTL);
rl_io(socket) = config_readw(socket, RL5C4XX_16BIT_IO_0);
rl_mem(socket) = config_readw(socket, RL5C4XX_16BIT_MEM_0);
rl_config(socket) = config_readw(socket, RL5C4XX_CONFIG);
}
static void ricoh_restore_state(struct yenta_socket *socket)
{
config_writew(socket, RL5C4XX_MISC, rl_misc(socket));
config_writew(socket, RL5C4XX_16BIT_CTL, rl_ctl(socket));
config_writew(socket, RL5C4XX_16BIT_IO_0, rl_io(socket));
config_writew(socket, RL5C4XX_16BIT_MEM_0, rl_mem(socket));
config_writew(socket, RL5C4XX_CONFIG, rl_config(socket));
}
/*
* Magic Ricoh initialization code..
*/
static int ricoh_override(struct yenta_socket *socket)
{
u16 config, ctl;
config = config_readw(socket, RL5C4XX_CONFIG);
/* Set the default timings, don't trust the original values */
ctl = RL5C4XX_16CTL_IO_TIMING | RL5C4XX_16CTL_MEM_TIMING;
if(socket->dev->device < PCI_DEVICE_ID_RICOH_RL5C475) {
ctl |= RL5C46X_16CTL_LEVEL_1 | RL5C46X_16CTL_LEVEL_2;
} else {
config |= RL5C4XX_CONFIG_PREFETCH;
}
config_writew(socket, RL5C4XX_16BIT_CTL, ctl);
config_writew(socket, RL5C4XX_CONFIG, config);
ricoh_set_zv(socket);
return 0;
}
#endif /* CONFIG_CARDBUS */
#endif /* _LINUX_RICOH_H */
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