Messages in this thread | | | Date | Fri, 11 Oct 2002 20:07:12 -0700 | From | Andrew Morton <> | Subject | Re: Strange load spikes on 2.4.19 kernel |
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Rob Mueller wrote: > > > > Filesystem is ext3 with one big / partition (that's a mistake > > > we won't repeat, but too late now). This should be mounted > > > with data=journal given the kernel command line above, though > > > it's a bit hard to tell from the dmesg log: > > > > > > > It's possible tht the journal keeps on filling. When that happens, > > everything has to wait for writeback into the main filesystem. > > Completion of that writeback frees up journal space and then everything > > can unblock. > > > > Suggest you try data=ordered. > > We have a 192M journal, and from the dmesg log it's saying that it's got a 5 > second flush interval, so I can't imagine that the journal is filling, but > we'll try it and see I guess. > > What I don't understand is why the spike is so sudden, and decays so slowly. > It's Friday night now, so the load is fairly low. I setup a loop to dump > uptime information every 10 seconds and attached the result below. It's > running smoothly, then 'bam', it's hit with something big, which then slowly > decays off. > > A few extra things: > 1. It happens every couple of minutes or so, but not exactly on any time, so > it's not a cron job or anything > 2. Viewing 'top', there are no extra processes obviously running when it > happens >
If it was this, one would expect it to happen every time you'd written 0.75 * 192 Mbytes to the filesystem. Which seems about right.
Easy enough to test though. - 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/
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