Re: Strange "flush" process bahaviour

[Piotr Szymaniak <szarpaj-TbOm9Ca2r9GrDJvtcaxF/A@public.gmane.org>]

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On Fri, Mar 29, 2013 at 12:15:10PM +0400, Vyacheslav Dubeyko wrote:
> I meant that sysrq-trigger output ends with resume about runnable tasks
> and locks in the system (for example):
> *snip*
> So, I need in full sysrq-trigger output for understanding situation on
> your side. Could you share it?

If this should be in echo t > /proc/sysrq-trigger then I shared full
output already. Maybe I'm missing some (debug?) features in kernel for
more verbose output.


> > Btw looking at ps aux output it seems, that this flush is hanging there
> > almost from first boot:
> > root       937 88.2  0.0      0     0 ?        S    Feb17 50160:39 [flush-8:0]
> > 
> 
> Could you share "cat /proc/partitions" and "mount" outputs? I need to
> understand what partition is processed by [flush-8:0].

~ # cat /proc/partitions
major minor  #blocks  name

   8        0    3915776 sda
   8        1      32768 sda1
   8        2      65536 sda2
   8        3    3816448 sda3
   8       16  156290904 sdb
   8       17    4200966 sdb1
   8       18     273105 sdb2
   8       19  146810002 sdb3
   8       20    5004247 sdb4
 254        0      65536 dm-0
 254        1  146808974 dm-1


~ # mount
rootfs on / type rootfs (rw)
/dev/sda3 on / type nilfs2 (rw,noatime,nodiratime,gcpid=16150)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /run type tmpfs (rw,nosuid,nodev,relatime,mode=755)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=10240k,nr_inodes=221714,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
/dev/mapper/chome on /home type btrfs (rw,noatime)


> > > I can easily reproduce the issue by big file (100 - 500 GB) deletion
> > > or truncation. Please, find description in:
> > > http://www.mail-archive.com/linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org/msg01504.html.
> > 
> > If this brings something new - I'm not using huge files like that (this
> > flush above is a 3.7G device). But if this reproduces the issue, it
> > could be related.  (:
> > 
> 
> Yes, it is really important to understand the situation on your side.
> Because you can have another reason of the issue with similar symptoms.
> So, we need to investigate your case more deeply, I think.

Got this issue on two different machines, but none of them uses nilfs2 at
device bigger then 60G (in fact, the partitions are, afair, around 30G and the
mentioned 3.7G).


Piotr Szymaniak.
-- 
I ten smród. Diabli wiedzą, co tam gniło, w tym mięsiwie, ale Redowi
wydało się, że sto tysięcy rozbitych cuchnących jaj wylanych na sto
tysięcy cuchnących rybich łbów i zdechłych kotów nie może śmierdzieć
tak, jak śmierdziała ta maź.
 -- Arkadij i Borys Strugaccy, „Piknik na skraju drogi”

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