at times, pdflush is taking over my system:
kernel 2.6.6-rc1-mm1
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
31276 jurriaan 25 0 76772 59m 8764 R 98.7 2.0 776:39.05 mencoder
3479 root 25 0 0 0 0 R 96.7 0.0 134:29.90 pdflush
1 root 16 0 1520 516 1368 S 0.0 0.0 0:10.50 init
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
2 0 3064 7428 71536 2696036 0 0 94 154 201 196 53 5 41 1
2 0 3064 7108 71556 2696424 0 0 128 303 1146 182 50 50 0 0
2 0 3064 6540 71556 2697036 0 0 192 238 1129 155 50 50 0 0
2 0 3064 6284 71556 2697512 0 0 128 228 1127 278 50 50 0 0
2 0 3064 7692 71564 2696076 0 0 192 266 1134 161 50 50 0 0
2 0 3064 7108 71564 2696688 0 0 192 302 1140 203 50 50 0 0
2 0 3064 6660 71568 2697092 0 0 128 232 1128 145 50 50 0 0
2 0 3064 6276 71588 2697616 0 0 128 309 1141 178 50 50 0 0
2 0 3064 7108 71588 2696732 0 0 192 290 1139 169 50 50 0 0
2 0 3064 6596 71600 2697332 0 0 192 260 1133 165 50 50 0 0
output from
#!/bin/sh
readprofile -r
readprofile -M10
sleep 30
readprofile -n -v -m /proc/kallsyms | sort +0.50 -n | tail -20
c0170978 __iget 172 2.1235
c0178af1 writeback_acquire 220 8.8000
c0178b18 writeback_release 223 4.7447
c0142757 __pagevec_release 237 4.3889
c0172151 wake_up_inode 270 4.2857
c02909b0 atomic_dec_and_lock 271 2.3362
c0339333 ide_intr 308 0.6498
c013ec60 mapping_tagged 376 3.5140
c0178224 sync_sb_inodes 393 0.5406
c0177f49 __sync_single_inode 469 0.9214
c0103029 default_idle 525 10.7143
c0142aff pagevec_lookup_tag 587 9.7833
c0142432 lru_add_drain 689 6.2072
c0138943 wait_on_page_bit 1112 5.2701
c0138910 page_waitqueue 9518 186.6275
c0142579 release_pages 23597 49.3661
c0138a16 unlock_page 23666 281.7381
c013e945 clear_page_dirty_for_io 24791 255.5773
c01797c5 mpage_writepages 30701 40.0274
c0138ec9 find_get_pages_tag 181934 1166.2436
.config:
CONFIG_X86=y
CONFIG_MMU=y
CONFIG_UID16=y
CONFIG_GENERIC_ISA_DMA=y
CONFIG_EXPERIMENTAL=y
CONFIG_BROKEN=y
CONFIG_BROKEN_ON_SMP=y
CONFIG_SWAP=y
CONFIG_SYSVIPC=y
CONFIG_SYSCTL=y
CONFIG_LOG_BUF_SHIFT=16
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_KALLSYMS=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_AS=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_OBSOLETE_MODPARM=y
CONFIG_KMOD=y
CONFIG_STOP_MACHINE=y
CONFIG_X86_PC=y
CONFIG_MPENTIUM4=y
CONFIG_X86_CMPXCHG=y
CONFIG_X86_XADD=y
CONFIG_X86_L1_CACHE_SHIFT=7
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_X86_WP_WORKS_OK=y
CONFIG_X86_INVLPG=y
CONFIG_X86_BSWAP=y
CONFIG_X86_POPAD_OK=y
CONFIG_X86_GOOD_APIC=y
CONFIG_X86_INTEL_USERCOPY=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_SMP=y
CONFIG_NR_CPUS=2
CONFIG_SCHED_SMT=y
CONFIG_PREEMPT=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
CONFIG_X86_TSC=y
CONFIG_X86_MCE=y
CONFIG_X86_MCE_NONFATAL=y
CONFIG_X86_MCE_P4THERMAL=y
CONFIG_MICROCODE=y
CONFIG_X86_MSR=y
CONFIG_X86_CPUID=y
CONFIG_HIGHMEM4G=y
CONFIG_HIGHMEM=y
CONFIG_HIGHPTE=y
CONFIG_MTRR=y
CONFIG_HAVE_DEC_LOCK=y
CONFIG_PM=y
CONFIG_ACPI=y
CONFIG_ACPI_BOOT=y
CONFIG_ACPI_INTERPRETER=y
CONFIG_ACPI_SLEEP=y
CONFIG_ACPI_SLEEP_PROC_FS=y
CONFIG_ACPI_AC=y
CONFIG_ACPI_BUTTON=y
CONFIG_ACPI_FAN=y
CONFIG_ACPI_PROCESSOR=y
CONFIG_ACPI_THERMAL=y
CONFIG_ACPI_DEBUG=y
CONFIG_ACPI_BUS=y
CONFIG_ACPI_EC=y
CONFIG_ACPI_POWER=y
CONFIG_ACPI_PCI=y
CONFIG_ACPI_SYSTEM=y
CONFIG_PCI=y
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y
CONFIG_PCI_MMCONFIG=y
CONFIG_PCI_NAMES=y
CONFIG_ISA=y
CONFIG_BINFMT_ELF=y
CONFIG_BINFMT_AOUT=y
CONFIG_BINFMT_MISC=y
CONFIG_PARPORT=y
CONFIG_PARPORT_PC=y
CONFIG_PARPORT_PC_CML1=y
CONFIG_PARPORT_1284=y
CONFIG_BLK_DEV_FD=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_IDE=y
CONFIG_BLK_DEV_IDE=y
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_BLK_DEV_IDECD=y
CONFIG_BLK_DEV_IDESCSI=y
CONFIG_IDE_GENERIC=y
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_BLK_DEV_ADMA=y
CONFIG_BLK_DEV_AMD74XX=y
CONFIG_BLK_DEV_HPT366=y
CONFIG_BLK_DEV_PIIX=y
CONFIG_BLK_DEV_PDC202XX_OLD=y
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_AUTO=y
CONFIG_SCSI=y
CONFIG_SCSI_PROC_FS=y
CONFIG_BLK_DEV_SD=y
CONFIG_CHR_DEV_ST=y
CONFIG_BLK_DEV_SR=y
CONFIG_CHR_DEV_SG=y
CONFIG_SCSI_MULTI_LUN=y
CONFIG_SCSI_REPORT_LUNS=y
CONFIG_SCSI_CONSTANTS=y
CONFIG_SCSI_SPI_ATTRS=y
CONFIG_SCSI_SYM53C8XX_2=y
CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=1
CONFIG_SCSI_SYM53C8XX_DEFAULT_TAGS=16
CONFIG_SCSI_SYM53C8XX_MAX_TAGS=64
CONFIG_SCSI_QLA2XXX=y
CONFIG_MD=y
CONFIG_BLK_DEV_MD=y
CONFIG_MD_LINEAR=y
CONFIG_MD_RAID0=y
CONFIG_MD_RAID1=y
CONFIG_MD_RAID5=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_ADVANCED_ROUTER=y
CONFIG_IP_ROUTE_VERBOSE=y
CONFIG_SYN_COOKIES=y
CONFIG_NETDEVICES=y
CONFIG_DUMMY=y
CONFIG_NET_ETHERNET=y
CONFIG_MII=y
CONFIG_NET_TULIP=y
CONFIG_TULIP=y
CONFIG_TULIP_MWI=y
CONFIG_TULIP_MMIO=y
CONFIG_NET_PCI=y
CONFIG_8139TOO=y
CONFIG_8139_RXBUF_IDX=2
CONFIG_TIGON3=m
CONFIG_INPUT=y
CONFIG_INPUT_MOUSEDEV=y
CONFIG_INPUT_MOUSEDEV_PSAUX=y
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
CONFIG_SOUND_GAMEPORT=y
CONFIG_SERIO=y
CONFIG_SERIO_I8042=y
CONFIG_SERIO_SERPORT=y
CONFIG_INPUT_KEYBOARD=y
CONFIG_KEYBOARD_ATKBD=y
CONFIG_INPUT_MOUSE=y
CONFIG_MOUSE_PS2=y
CONFIG_INPUT_MISC=y
CONFIG_INPUT_PCSPKR=y
CONFIG_VT=y
CONFIG_VT_CONSOLE=y
CONFIG_HW_CONSOLE=y
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_CORE=y
CONFIG_UNIX98_PTYS=y
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256
CONFIG_PRINTER=y
CONFIG_WATCHDOG=y
CONFIG_SOFT_WATCHDOG=y
CONFIG_HW_RANDOM=y
CONFIG_RTC=y
CONFIG_AGP=y
CONFIG_AGP_INTEL=y
CONFIG_DRM=y
CONFIG_DRM_RADEON=y
CONFIG_DRM_MGA=y
CONFIG_HANGCHECK_TIMER=y
CONFIG_I2C=y
CONFIG_I2C_CHARDEV=m
CONFIG_I2C_ALGOBIT=y
CONFIG_I2C_ISA=m
CONFIG_I2C_VIAPRO=m
CONFIG_I2C_SENSOR=m
CONFIG_SENSORS_VIA686A=m
CONFIG_SENSORS_W83781D=m
CONFIG_SENSORS_EEPROM=m
CONFIG_FB=y
CONFIG_VIDEO_SELECT=y
CONFIG_FB_MATROX=y
CONFIG_FB_MATROX_G450=y
CONFIG_FB_MATROX_G100=y
CONFIG_FB_RADEON=y
CONFIG_FB_RADEON_I2C=y
CONFIG_FB_RADEON_DEBUG=y
CONFIG_FB_3DFX=y
CONFIG_VGA_CONSOLE=y
CONFIG_DUMMY_CONSOLE=y
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_PCI_CONSOLE=y
CONFIG_FONTS=y
CONFIG_FONT_SUN12x22=y
CONFIG_LOGO=y
CONFIG_LOGO_LINUX_MONO=y
CONFIG_LOGO_LINUX_VGA16=y
CONFIG_LOGO_LINUX_CLUT224=y
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_HWDEP=y
CONFIG_SND_RAWMIDI=y
CONFIG_SND_SEQUENCER=y
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_SEQUENCER_OSS=y
CONFIG_SND_RTCTIMER=y
CONFIG_SND_MPU401_UART=y
CONFIG_SND_OPL3_LIB=y
CONFIG_SND_AC97_CODEC=y
CONFIG_SND_EMU10K1=y
CONFIG_SND_CMIPCI=y
CONFIG_SND_INTEL8X0=y
CONFIG_SND_VIA82XX=y
CONFIG_USB=y
CONFIG_USB_DEVICEFS=y
CONFIG_USB_EHCI_HCD=y
CONFIG_USB_UHCI_HCD=y
CONFIG_USB_PRINTER=y
CONFIG_USB_HID=y
CONFIG_USB_HIDINPUT=y
CONFIG_EXT2_FS=y
CONFIG_EXT3_FS=y
CONFIG_EXT3_FS_XATTR=y
CONFIG_JBD=y
CONFIG_FS_MBCACHE=y
CONFIG_REISERFS_FS=y
CONFIG_XFS_FS=y
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
CONFIG_UDF_FS=y
CONFIG_FAT_FS=y
CONFIG_VFAT_FS=y
CONFIG_NTFS_FS=y
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
CONFIG_RAMFS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_LOCKD=y
CONFIG_LOCKD_V4=y
CONFIG_SUNRPC=y
CONFIG_MSDOS_PARTITION=y
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_CODEPAGE_437=y
CONFIG_NLS_ISO8859_1=y
CONFIG_DEBUG_KERNEL=y
CONFIG_EARLY_PRINTK=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_FRAME_POINTER=y
CONFIG_4KSTACKS=y
CONFIG_SCHEDSTATS=y
CONFIG_X86_FIND_SMP_CONFIG=y
CONFIG_X86_MPPARSE=y
CONFIG_CRC32=y
CONFIG_X86_SMP=y
CONFIG_X86_HT=y
CONFIG_X86_BIOS_REBOOT=y
CONFIG_X86_TRAMPOLINE=y
CONFIG_X86_STD_RESOURCES=y
CONFIG_PC=y
/proc/sys/vm/block_dump:0
/proc/sys/vm/dirty_background_ratio:10
/proc/sys/vm/dirty_expire_centisecs:3000
/proc/sys/vm/dirty_ratio:40
/proc/sys/vm/dirty_writeback_centisecs:500
/proc/sys/vm/laptop_mode:0
/proc/sys/vm/lower_zone_protection:0
/proc/sys/vm/max_map_count:65536
/proc/sys/vm/min_free_kbytes:957
/proc/sys/vm/nr_pdflush_threads:2
/proc/sys/vm/overcommit_memory:0
/proc/sys/vm/overcommit_ratio:50
/proc/sys/vm/page-cluster:3
/proc/sys/vm/swappiness:60
MemTotal: 3107928 kB
MemFree: 6540 kB
Buffers: 72764 kB
Cached: 2696996 kB
SwapCached: 1240 kB
Active: 342292 kB
Inactive: 2625092 kB
HighTotal: 2228160 kB
HighFree: 1088 kB
LowTotal: 879768 kB
LowFree: 5452 kB
SwapTotal: 4016232 kB
SwapFree: 4013180 kB
Dirty: 11868 kB
Writeback: 0 kB
Mapped: 212944 kB
Slab: 107076 kB
Committed_AS: 236832 kB
PageTables: 1252 kB
VmallocTotal: 114680 kB
VmallocUsed: 27256 kB
VmallocChunk: 87420 kB
Any ideas? I've seen this in earlier kernels, but this is the first time
I've been able to profile it. Usually, when I leave the system like this
for the night, pdlush has quieted down by morning. That does hamper the
encoding speed, however.
Thanks,
Jurriaan
--
He was back, and they could like it or lump it.
Simon R Green - Blue Moon Rising
Debian (Unstable) GNU/Linux 2.6.6-rc1-mm1 2x6062 bogomips 2.53 2.32
Jurriaan <[email protected]> wrote:
>
> at times, pdflush is taking over my system:
yup, there's some logic error in there. If I could reproduce it, it would
be fixed in a jiffy :(
Which filesystems are in active use at the time? reiserfs?
From: Andrew Morton <[email protected]>
Date: Tue, Apr 20, 2004 at 07:15:33PM -0700
> Jurriaan <[email protected]> wrote:
> >
> > at times, pdflush is taking over my system:
>
> yup, there's some logic error in there. If I could reproduce it, it would
> be fixed in a jiffy :(
>
> Which filesystems are in active use at the time? reiserfs?
>
mostly, yes, also ext3, and raid-1 and linear raid. I can't always
reproduce it either, unfortunately :-(
/dev/md3 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/md4 on /usr type ext3 (rw,errors=remount-ro)
/dev/md2 on /var type ext3 (rw,errors=remount-ro)
sysfs on /devices type sysfs (rw)
/dev/md5 on /vmware type reiserfs (rw)
/dev/md0 on /home type reiserfs (rw)
/dev/md1 on /var/spool/news_binary type reiserfs (rw)
/dev/hde1 on /space1 type reiserfs (rw,noexec,nosuid,nodev)
/dev/hdk1 on /space2 type reiserfs (rw,noexec,nosuid,nodev)
/dev/hdg1 on /space3 type reiserfs (rw,noexec,nosuid,nodev)
Personalities : [linear] [raid0] [raid1] [raid5]
md3 : active raid1 hdc1[0] hda1[1]
497856 blocks [2/2] [UU]
md4 : active raid1 hdc3[0] hda3[1]
8008320 blocks [2/2] [UU]
md2 : active raid1 hdc5[0] hda5[1]
16008640 blocks [2/2] [UU]
md5 : active raid1 hdc6[0] hda6[1]
8008256 blocks [2/2] [UU]
md1 : active linear hdi1[2] hdc7[1] hda7[0]
76909568 blocks 64k rounding
md0 : active raid1 hdc8[0] hda8[1]
62645312 blocks [2/2] [UU]
unused devices: <none>
Kind regards,
Jurriaan
--
But what can you do with it?
ubiquitous cry from Linux-user partner
Debian (Unstable) GNU/Linux 2.6.6-rc1-mm1 2x6062 bogomips load av: 2.07 2.06 2.17
Jurriaan <[email protected]> wrote:
>
> From: Andrew Morton <[email protected]>
> Date: Tue, Apr 20, 2004 at 07:15:33PM -0700
> > Jurriaan <[email protected]> wrote:
> > >
> > > at times, pdflush is taking over my system:
> >
> > yup, there's some logic error in there. If I could reproduce it, it would
> > be fixed in a jiffy :(
> >
> > Which filesystems are in active use at the time? reiserfs?
> >
>
> mostly, yes, also ext3, and raid-1 and linear raid. I can't always
> reproduce it either, unfortunately :-(
I'm suspecting that reiserfs_writepage() is redirty pages rather than
writing them and writeback is livelocking.
Could you try this?
---
25-akpm/fs/buffer.c | 2 +-
25-akpm/fs/ext3/inode.c | 6 +++---
25-akpm/fs/ntfs/aops.c | 15 +++------------
25-akpm/fs/reiserfs/inode.c | 2 +-
25-akpm/include/linux/mm.h | 2 ++
25-akpm/mm/page-writeback.c | 12 ++++++++++++
6 files changed, 22 insertions(+), 17 deletions(-)
diff -puN fs/buffer.c~writeback-livelock-fix fs/buffer.c
--- 25/fs/buffer.c~writeback-livelock-fix 2004-04-20 23:46:12.979432024 -0700
+++ 25-akpm/fs/buffer.c 2004-04-20 23:46:13.000428832 -0700
@@ -1826,7 +1826,7 @@ static int __block_write_full_page(struc
if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
lock_buffer(bh);
} else if (test_set_buffer_locked(bh)) {
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
continue;
}
if (test_clear_buffer_dirty(bh)) {
diff -puN fs/ext3/inode.c~writeback-livelock-fix fs/ext3/inode.c
--- 25/fs/ext3/inode.c~writeback-livelock-fix 2004-04-20 23:46:12.981431720 -0700
+++ 25-akpm/fs/ext3/inode.c 2004-04-20 23:46:12.998429136 -0700
@@ -1311,7 +1311,7 @@ static int ext3_ordered_writepage(struct
return ret;
out_fail:
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
unlock_page(page);
return ret;
}
@@ -1340,7 +1340,7 @@ static int ext3_writeback_writepage(stru
return ret;
out_fail:
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
unlock_page(page);
return ret;
}
@@ -1396,7 +1396,7 @@ out:
return ret;
no_write:
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
out_unlock:
unlock_page(page);
goto out;
diff -puN fs/ntfs/aops.c~writeback-livelock-fix fs/ntfs/aops.c
--- 25/fs/ntfs/aops.c~writeback-livelock-fix 2004-04-20 23:46:12.983431416 -0700
+++ 25-akpm/fs/ntfs/aops.c 2004-04-20 23:46:12.995429592 -0700
@@ -499,10 +499,7 @@ static int ntfs_write_block(struct page
* Put the page back on mapping->dirty_pages, but leave its
* buffer's dirty state as-is.
*/
- // FIXME: Once Andrew's -EAGAIN patch goes in, remove the
- // __set_page_dirty_nobuffers(page) and return -EAGAIN instead
- // of zero.
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
@@ -733,10 +730,7 @@ lock_retry_remap:
* Put the page back on mapping->dirty_pages, but
* leave its buffer's dirty state as-is.
*/
- // FIXME: Once Andrew's -EAGAIN patch goes in, remove
- // the __set_page_dirty_nobuffers(page) and set err to
- // -EAGAIN instead of zero.
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
err = 0;
} else
SetPageError(page);
@@ -986,10 +980,7 @@ err_out:
* Put the page back on mapping->dirty_pages, but leave its
* buffer's dirty state as-is.
*/
- // FIXME: Once Andrew's -EAGAIN patch goes in, remove the
- // __set_page_dirty_nobuffers(page) and set err to -EAGAIN
- // instead of zero.
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
err = 0;
} else {
ntfs_error(vi->i_sb, "Resident attribute write failed with "
diff -puN fs/reiserfs/inode.c~writeback-livelock-fix fs/reiserfs/inode.c
--- 25/fs/reiserfs/inode.c~writeback-livelock-fix 2004-04-20 23:46:12.985431112 -0700
+++ 25-akpm/fs/reiserfs/inode.c 2004-04-20 23:46:12.993429896 -0700
@@ -2112,7 +2112,7 @@ static int reiserfs_write_full_page(stru
lock_buffer(bh);
} else {
if (test_set_buffer_locked(bh)) {
- __set_page_dirty_nobuffers(page);
+ redirty_page_for_writepage(wbc, page);
continue;
}
}
diff -puN include/linux/mm.h~writeback-livelock-fix include/linux/mm.h
--- 25/include/linux/mm.h~writeback-livelock-fix 2004-04-20 23:46:12.986430960 -0700
+++ 25-akpm/include/linux/mm.h 2004-04-20 23:46:12.992430048 -0700
@@ -499,6 +499,8 @@ int get_user_pages(struct task_struct *t
int __set_page_dirty_buffers(struct page *page);
int __set_page_dirty_nobuffers(struct page *page);
+int redirty_page_for_writepage(struct writeback_control *wbc,
+ struct page *page);
int FASTCALL(set_page_dirty(struct page *page));
int set_page_dirty_lock(struct page *page);
int clear_page_dirty_for_io(struct page *page);
diff -puN mm/page-writeback.c~writeback-livelock-fix mm/page-writeback.c
--- 25/mm/page-writeback.c~writeback-livelock-fix 2004-04-20 23:46:12.988430656 -0700
+++ 25-akpm/mm/page-writeback.c 2004-04-20 23:46:13.001428680 -0700
@@ -581,6 +581,18 @@ int __set_page_dirty_nobuffers(struct pa
EXPORT_SYMBOL(__set_page_dirty_nobuffers);
/*
+ * When a writepage implementation decides that it doesn't want to write this
+ * page for some reason, it should redirty the locked page via
+ * redirty_page_for_writepage() and it should then unlock the page and return 0
+ */
+int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
+{
+ wbc->pages_skipped++;
+ return __set_page_dirty_nobuffers(page);
+}
+EXPORT_SYMBOL(redirty_page_for_writepage);
+
+/*
* If the mapping doesn't provide a set_page_dirty a_op, then
* just fall through and assume that it wants buffer_heads.
*/
_