Messages in this thread | | | Date | Thu, 8 Sep 2011 04:22:29 -0400 | From | Christoph Hellwig <> | Subject | Re: Help with implementing some form of barriers in 3.0 kernels. |
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On Wed, Sep 07, 2011 at 05:31:37PM -0400, Vivek Goyal wrote: > I have a basic question. In old guest why BARRIER handling on request > queue is not sufficient for sequencing and ordering of requests and why > xen-blkfront and qemu have to do something about it. > > I am also wondering if virtio-blk have similar issues?
Mainline xen-blkfront was using ORDERED_TAG before, which meant bypassing the sequencer entirely, as well as not beeing able to implement plain cache flushes as used by ->fsync.
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