Messages in this thread | | | From | Steven Cole <> | Subject | Re: 1352 NUL bytes at the end of a page? (was Re: Assertion `s && s->tree' failed: The saga continues.) | Date | Sun, 16 May 2004 20:12:56 -0600 |
| |
On Sunday 16 May 2004 05:53 pm, Andrea Arcangeli wrote: > On Sun, May 16, 2004 at 04:11:16PM -0600, Steven Cole wrote: > > On Sunday 16 May 2004 03:29 pm, Andrew Morton wrote: > > > Steven Cole <elenstev@mesatop.com> wrote: > > > > > > > > Anyway, although the regression for my particular machine for this > > > > particular load may be interesting, the good news is that I've seen > > > > none of the failures which started this whole thread, which are relatively > > > > easily reproduceable with PREEMPT set. > > > > > > So... would it be correct to say that with CONFIG_PREEMPT, ppp or its > > > underlying driver stack > > > > > > a) screws up the connection and hangs and > > > > > > b) scribbles on pagecache? > > > > > > Because if so, the same will probably happen on SMP. > > > > > Perhaps someone has the hardware to test this. > > > > To summarize my experience with the past 24 hours of testing: > > Without PREEMPT , everything is rock solid. > > so we've two separate problems: the first is the ppp instability with > preempt, the second is a regresion in the vm heuristics between 2.6.3 > and 2.6.5. Yes, that is correct. The instability was first noticed about one month ago when doing a bk pull from linus' repository. I've been updating my kernel via bk almost nightly, and around the time of 2.6.6-rc1 (IIRC), I got the Assertion `s && s->tree' failed message from bk. At first it was thought to be related to using an older version (3.0.1) of bk, so that was updated. A few days later, the problem recurred. Since it only happened about 15% to 20% of the time, and was easy to recover from, I didn't scream too loudly or too often to bitmover. But then, the problem started becoming more persistent about a week ago, so I began complaining again. I managed to get a bitkeeper-generated file to bitmover, who discovered that a very odd (or even in this case) number of NUL bytes existed where they should not exist. Hence this thread.
Then during the course of testing, I noticed the significant difference in time it took to run a test script supplied by bitkeeper for current kernels versus an older vendor kernel. Hence your being cc'ed.
> > > and I (cringes at the thought) may repeat some bk pulls with > > PREEMPT set. > > I've heard other reports of preempt being unstable with some sound > stuff, just in case are you using sound drivers at all during that > workload? > > Yes, mea culpa. CONFIG_SND_ENS1371=y.
Steven - 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/
| |