Messages in this thread |  | | | Date | Wed, 28 Apr 2004 08:50:40 -0500 (CDT) | | From | Brent Cook <> | | Subject | Re: pdflush eating a lot of CPU on heavy NFS I/O |
| |
On Tue, 27 Apr 2004, Andrew Morton wrote:
> Brent Cook <busterbcook@yahoo.com> wrote: > > > > Running any kernel from the 2.6.6-rc* series (and a few previous > > -mm*'s), > > It's a shame this wasn't reported earlier.
Since it was a pretty big deal on my system, I just assumed it was for other people's too, and that someone else would have reported it by now. I only got concerned when it persisted between rc's.
> > the pdflush process starts using near 100% CPU indefinitely after > > a few minutes of initial NFS traffic, as far as I can tell. > > Please confirm that the problem is observed on the NFS client and not the > NFS server? I'll assume the client.
Yes, both affected machines had the issue when connecting as a client to a 2.4.25-based NFS server.
> What other filesystems are in use on the client?
One uses Reiser on /, the other uses ext3 on /. Here is the mount table for one machine:
/dev/hda3 on / type ext3 (rw) none on /dev/pts type devpts (rw,gid=5,mode=620) none on /proc type proc (rw) none on /sys type sysfs (rw) usbfs on /proc/bus/usb type usbfs (rw) ozma:/home on /home type nfs (rw,addr=192.168.1.1)
Running 2.6.6-rc2-mm1, Here is a shot compiling KDE with the source on the NFS mount, -j2. This is the initial state:
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 12091 busterb 25 0 63524 59M 5140 R 38.4 23.8 0:19 0 cc1plus 12199 busterb 25 0 55660 52M 5140 R 38.0 20.8 0:07 0 cc1plus 7 root 16 0 0 0 0 SW 4.9 0.0 0:03 0 pdflush
About 10 minutes into the process, pdflush starts taking over:
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 7 root 25 0 0 0 0 RW 34.4 0.0 3:05 0 pdflush 17856 busterb 25 0 69400 65M 5140 R 34.4 26.1 0:31 0 cc1plus 19466 busterb 25 0 43732 39M 5140 R 26.3 15.5 0:03 0 cc1plus
After stopping the compile, pdflush remains until a reboot:
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 7 root 25 0 0 0 0 RW 98.0 0.0 3:21 0 pdflush
The network light will flash continually on each machine once pdflush gets into this state, which makes me think NFS. Each machine has 512-256 MB of ram and a single CPU.
- Brent - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |