Messages in this thread | | | Date | Tue, 19 Feb 2002 09:42:14 -0800 | From | john <> | Subject | Re: kupdated using all CPU |
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[Mon, Feb 18, 2002 at 09:53:08PM -0700] ebiederm@xmission.com wrote: + Andrew Morton <akpm@zip.com.au> writes: + + > john wrote: + > > + > > [Mon, Feb 18, 2002 at 02:13:06PM -0800] akpm@zip.com.au wrote: + > > + john wrote: + > > + > + > > + > hi, + > > + > ive searched all over and found many references to this problem, but + > > + > never found an actual solution. the problem is that during heavy + > > + > disk I/O, kupdated will periodically take up ALL the cpu. + > > + + > > + I've seen a couple of reports of this, nothing to indicate that it's + > > + a common problem? + > > + + > > + In the other reports, it was related to extremely low disk throughput. + > > + What does `hdparm -t /dev/hda' say? + > > + > > root@doom:~# hdparm -t /dev/hda + > > + > > /dev/hda: + > > Timing buffered disk reads: 64 MB in 25.60 seconds = 2.50 MB/sec + > + > ugh. OK, I'll see if I cen reproduce this - there's no reason + > why disk suckiness should cause high CPU load. But you need to + > pay some attention to your IDE settings in kernel config, and + > possibly tuning. + + + Another possibility with the same symptoms is that there are simply + very large I/O request starving everything else out. When some + crucial data needs to be paged back in. john can you confirm you + looked in top and saw kupdate taking 100% of the cpu?
yes, i did. another thing that makes it pretty obvious is the cpu time reported by ps. kupdated cpu time will stay 0:00 until i run into the condition i described. then kupdated cpu time will jump as much as 0:45.
but i have fixed the issue by using the correct ide driver. though, someone may want to look into this anyway...dunno.. -j - 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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