[lkml]   [2000]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Blocked processes <=> Elevator starvation?
On Sun, 8 Oct 2000, Rik van Riel wrote:

> On Sun, 8 Oct 2000, Rui Sousa wrote:
> > After starting 2 processes that scan a lot of files (diff, find,
> > slocate, ...) it's impossible to run any other processes that
> > touch the disk, they will stall until one of the first two stop.
> > Could this be a sign of starvation in the elevator code?
> It could well be. I've seen this problem too and don't
> really have another explanation for this phenomenon.
> OTOH, maybe there is another reason for it that hasn't
> been found yet ;)

I finally had time to give this a better look. It now seems the problem
is in the VM system.

I patched a test10-pre4 kernel with kdb, then started two "diff -ur
linux-2.4.0testX linux-2.4.0testY > log1" and two "find / -true >
log". After this I tried cat"ing" a small file. The cat never
returned. At this point I entered kdb and did a stack trace on the "cat"


So it seems the process is either in a loop in ___wait_on_page()
racing for the PageLock or it never wakes-up... (I guess I could add a
printk to check which)
Unfortunately I didn't find anything obviously wrong with the code.
I hope you can do a better job tracking the problem down.

As a reminder:
i686, UP, 64Mb RAM, IDE disks, ext2.

Rui Sousa

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:45    [W:0.080 / U:1.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site