Messages in this thread | | | Date | Wed, 7 Mar 2001 20:56:59 +0000 | From | "Stephen C. Tweedie" <> |
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Hi,
On Wed, Mar 07, 2001 at 09:15:36PM +0100, Jens Axboe wrote: > On Wed, Mar 07 2001, Stephen C. Tweedie wrote: > > > > For most fs'es, that's not an issue. The fs won't start writeback on > > the primary disk at all until the journal commit has been acknowledged > > as firm on disk. > > But do you then force wait on that journal commit?
It doesn't matter too much --- it's only the writeback which is doing this (ext3 uses a separate journal thread for it), so any sleep is only there to wait for the moment when writeback can safely begin: users of the filesystem won't see any stalls.
> A barrier operation is sufficient then. So you're saying don't > over design, a simple barrier is all you need?
Pretty much so. The simple barrier is the only thing which can be effectively optimised at the hardware level with SCSI anyway.
Cheers, Stephen - 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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