:
:In message <[EMAIL PROTECTED]>, Matthew Dillon writes:
:
:> Sigh. Ok, I've fixed the VN device. Again. It looks like the removal of
:> /dev/drum removed a little too much. We need the device infrastructure
:> to support the VN device's use of swap backing store.
:>
:> This patch below is a commit candidate. It could use a review, then I'll
:> commit it.
:
:Could you please explain why you need this ?
:
:--
:Poul-Henning Kamp FreeBSD coreteam member
:[EMAIL PROTECTED] "Real hackers run -current on their laptop."
:FreeBSD -- It will take a long time before progress goes too far!
VN calls vm_pager_strategy() which collects I/O in filesystem buffers
(bp)'s in order to cluster the I/O, and you cannot initiate I/O on
filesystem buffers without a valid b_dev.
So, the jist of the problem is that in order to get reasonable performance
out of the thing (i.e. not issue 4K I/O's to the disk), we have to use
filesystem buffers which means the bp must be properly initialized.
-Matt
Matthew Dillon
<[EMAIL PROTECTED]>
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