讨论一下：读写硬盘时，系统会反应很慢！

faxian

我的系统（testing)在硬盘大量读写时，比如aptitude更新，其它的
操作会反应很慢，至少比xp要糟糕。是5400笔记本硬盘，DMA已经开启。大家也是这种情况吗？是linux本身的问题吗？

# hdparm -v /dev/hda1

/dev/hda1:
multcount     = 16 (on)
IO_support    =  1 (32-bit)
unmaskirq     =  1 (on)
using_dma     =  1 (on)
keepsettings  =  0 (off)
readonly      =  0 (off)
readahead     = 256 (on)
geometry      = 16383/255/63, sectors = 2298177, start = 63
自己编译的内核，下面是相关的配置：

CONFIG_HAVE_IDE=y
CONFIG_IDE=y
CONFIG_BLK_DEV_IDE=y

#
# Please see Documentation/ide/ide.txt for help/info on IDE drives
#
# CONFIG_BLK_DEV_IDE_SATA is not set
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_IDEDISK_MULTI_MODE=y
# CONFIG_BLK_DEV_IDECS is not set
# CONFIG_BLK_DEV_DELKIN is not set
# CONFIG_BLK_DEV_IDECD is not set
# CONFIG_BLK_DEV_IDETAPE is not set
# CONFIG_BLK_DEV_IDEFLOPPY is not set
# CONFIG_BLK_DEV_IDESCSI is not set
CONFIG_BLK_DEV_IDEACPI=y
# CONFIG_IDE_TASK_IOCTL is not set
# CONFIG_IDE_PROC_FS is not set

#
# IDE chipset support/bugfixes
#
# CONFIG_IDE_GENERIC is not set
# CONFIG_BLK_DEV_PLATFORM is not set
# CONFIG_BLK_DEV_CMD640 is not set
# CONFIG_BLK_DEV_IDEPNP is not set
CONFIG_BLK_DEV_IDEDMA_SFF=y

#
# PCI IDE chipsets support
#
CONFIG_BLK_DEV_IDEPCI=y
# CONFIG_IDEPCI_PCIBUS_ORDER is not set
# CONFIG_BLK_DEV_GENERIC is not set
# CONFIG_BLK_DEV_OPTI621 is not set
# CONFIG_BLK_DEV_RZ1000 is not set
CONFIG_BLK_DEV_IDEDMA_PCI=y
# CONFIG_BLK_DEV_AEC62XX is not set
# CONFIG_BLK_DEV_ALI15X3 is not set
# CONFIG_BLK_DEV_AMD74XX is not set
# CONFIG_BLK_DEV_ATIIXP is not set
# CONFIG_BLK_DEV_CMD64X is not set
# CONFIG_BLK_DEV_TRIFLEX is not set
# CONFIG_BLK_DEV_CY82C693 is not set
# CONFIG_BLK_DEV_CS5520 is not set
# CONFIG_BLK_DEV_CS5530 is not set
# CONFIG_BLK_DEV_CS5535 is not set
# CONFIG_BLK_DEV_HPT34X is not set
# CONFIG_BLK_DEV_HPT366 is not set
# CONFIG_BLK_DEV_JMICRON is not set
# CONFIG_BLK_DEV_SC1200 is not set
CONFIG_BLK_DEV_PIIX=y
# CONFIG_BLK_DEV_IT8213 is not set
# CONFIG_BLK_DEV_IT821X is not set
# CONFIG_BLK_DEV_NS87415 is not set
# CONFIG_BLK_DEV_PDC202XX_OLD is not set
# CONFIG_BLK_DEV_PDC202XX_NEW is not set
# CONFIG_BLK_DEV_SVWKS is not set
# CONFIG_BLK_DEV_SIIMAGE is not set
# CONFIG_BLK_DEV_SIS5513 is not set
# CONFIG_BLK_DEV_SLC90E66 is not set
# CONFIG_BLK_DEV_TRM290 is not set
# CONFIG_BLK_DEV_VIA82CXXX is not set
# CONFIG_BLK_DEV_TC86C001 is not set
CONFIG_BLK_DEV_IDEDMA=y
# CONFIG_BLK_DEV_HD_ONLY is not set
# CONFIG_BLK_DEV_HD is not set

d00m3d

Post by faxian;1883383
我的系统（testing)在硬盘大量读写时，比如aptitude更新，其它的
操作会反应很慢，至少比xp要糟糕。是5400笔记本硬盘，DMA已经开启。大家也是这种情况吗？是linux本身的问题吗？

# hdparm -v /dev/hda1

/dev/hda1:
multcount     = 16 (on)
IO_support    =  1 (32-bit)
unmaskirq     =  1 (on)
using_dma     =  1 (on)
keepsettings  =  0 (off)
readonly      =  0 (off)
[color="Red"] readahead     = 256 (on)
geometry      = 16383/255/63, sectors = 2298177, start = 63

把 readahead buffer 加大到 1024 会有一点帮助，即

hdparm -a1024 /dev/hda

另，系统在资源不足的情况会启用 swap 作虚拟内存，如机器本身内存较少，最好尽量避免消耗大量内存的桌面或软件

faxian

谢谢版主回复。readahead设为1024没有变化。可能是我内存太小。

d00m3d

內存有多少？

wm 方面最好找些輕量級的，如 icewm，jwm 之類的