severe slowdown with 2.4 series w/heavy disk access

severe slowdown with 2.4 series w/heavy disk access

Post by Paul Bole » Fri, 28 Dec 2001 01:40:07

> >              total       used       free     shared    buffers
> > cached
> > Mem:        417472     412192       5280          0      20632
> > 315680

> Thyose values dont show any problems. In fact your machine seems to think it
> had a ton of free memory to waste and has let it fill up with stuff that has
> been accessed - just on the chance that it may be reused.

> It hasn't even felt enough memory pressure to start swapping. When you
> say it "becomes slow", what precisely becomes slow ?

When this happens in X, the mouse drags and skips, any processes running
(like tar/gzip. ls in an empty dir takes about 10 seconds) slow down,
and it happens usually for about 10sec-2min, often for no apparent
reason.  The big decompression was just a way I can easily duplicate
it.  Oddly enough though, according to top, it caches all that memory at
once, and my free goes down to 5 megs, with the system*/slow to
respond, for 10sec-2min.  Even typing in the console has delay before
the characters appear, and according to top, tar and gz are both using
under 1% cpu while this happens, and about 50% of the cpu is in use by
the system (not by any processes that I can see.  kupdated goes up to
about 0.3% during this)


> Also what disks do you have and how are they set up ?
> -

/dev/hdb3 on / type ext2 (rw)
/dev/hdb4 on /home type ext2 (rw)
/dev/hda1 on /dos/c type vfat (rw)
/dev/hdb1 on /dos/d type vfat (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
none on /proc type proc (rw)

and my swap is /dev/hdb2
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in

More majordomo info at
Please read the FAQ at


1. severe slowdown with 2.4 series w/heavy disk access (revisited)


Anyone remember this thread:

   "severe slowdown with 2.4 series w/heavy disk access"

It describes the tendency of 2.4 series kernels to slowdown under I/O load.
Well, that problem still seems to be alive and kicking. And no, it is not
related to reiserfs as I previously suggested in this thread:

   "Abysmal interactive performance on 2.4.linus", archived here:

I removed the last reiserfs partition quite some time ago, currently running
mostly ext3 with ext2 root fs.

The systems use IDE disks, I don't have any SCSI-systems handy to test whether
this might be IDE-only (anyone?). Currently running 2.4.18 (with preempt and
lowlatency, but the problems are NOT related to those patches as they also hit
unpatched kernels) on SMP (Abit BP-6 yeah yeah I know but it does not seem to
be specific to the BP-6).

Does anyone else see these problems? Specifically, does anyone with a
SCSI-based system see this happening? Also, does anyone who uses only ext2 (no
ext3 or reiserfs, let alone jfs/xfs or any other journaling fs) see this?


 [ BTW: I'm moving to Sweden, and am looking for a project/job in V?stra
   G?taland, preferrably G?teborg... Anyone know anything interesting? ]
  WWWWW      ________________________
 ## o o\    /     Frank de Lange     \
 }#   \|   /                          \
  \ `--| _/     <Hacker for Hire>      \
   `---'  \                            /

 [ "Omnis enim res, quae dando non deficit, dum habetur
    et non datur, nondum habetur, quomodo habenda est."  ]
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in

More majordomo info at
Please read the FAQ at

2. ping and sendto error

3. Oopses with heavy disk activity with 2.4 on VIA Apollo (VT82C586B)

4. what flavor of linux should I start off with ? ( newbie )

5. 3c90x "overruns" causing severe network slowdown

6. Nice Linux Article

7. freeze during heavy (SCSI) disk access

8. Sleeping until a file exists

9. HP Netserver LD PRO 200 freezes under heavy disk access

10. RS6000 almost stops with heavy disk access.

11. Severe paging problem in Solaris 2.4

12. Severe Linux 2.4 kernel memory leakage

13. severe problems with linux (2.4.x) and dualhead xf86 (4.0.x)