Messages in this thread | | | Date | Wed, 25 Apr 2007 13:54:48 +0400 | From | Brad Campbell <> | Subject | Re: [OOPS] 2.6.21-rc6-git5 in cfq_dispatch_insert |
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Neil Brown wrote: > On Wednesday April 25, jens.axboe@oracle.com wrote: >> BUT... That may explain while we are only seeing it on md. Would md >> ever be issuing such requests that trigger this condition? > > Can someone remind me which raid level(s) was/were involved?
Raid-5 gegraded here, But I've had it on my server on a fully functioning raid-5 also. Don't think I've seen it on any of my raid-6 yet.
> I guess it could happen with raid4/5/6. A read request that was > properly aligned (and we do encourage proper alignment) will be passed > directly to the underlying device. A concurrent write elsewhere could > require the same block to be read into the stripe-cache to enable a > parity calculation. So you could get two reads at the same block > address.
Except all the filesystems I've had this occur on are Ext3 and all are mounted noatime, with no processes ever writing to the filesystems. So here it occurs with reads only.
Brad -- "Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so." -- Douglas Adams - 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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