Re: 2.4.17 RAID-1 EXT3 reliable to hang....

From: Andrew Morton (
Date: Mon Jan 07 2002 - 05:09:29 EST

Richard Guenther wrote:
> On Mon, 7 Jan 2002, Oliver Paukstadt wrote:
> > Heavy traffic on ext3 seems to cause short system freezes.
> I see dropped frames while watching TV (bttv chip, xawtv in overlay mode,
> XFree 4.1.0)
> since I use ext3 (2.4.16&17). Always during disk activity (IDE, umask irq
> and dma enabled). From what I know the bttv driver does it seems to loose
> interrupts!? This doesnt happen with ext2.

ext3 never blocks interrupts. It _may_ cause increased interrupt
latency than ext2 by the very large linear writes which it does. These
may cause other parts of the kernel to block interrupts for longer.

However, more likely that it's a scheduling latency problem. Sigh.
I spent *ages* on the ext3 buffer writeout code and it's still not
ideal. Can you test with this patch applied?

It should go into 2.4.17 OK.

> ...
> By any chance, is some global lock held during any IO intensive part of
> ext3?

Yes, a couple. But on uniprocessor it's more a matter of the kernel
failing to context switch promptly.

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

This archive was generated by hypermail 2b29 : Mon Jan 07 2002 - 21:00:33 EST