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Date:      Fri, 18 Apr 1997 12:49:58 +0930 (CST)
From:      Michael Smith <msmith@atrad.adelaide.edu.au>
To:        hasty@rah.star-gate.com (Amancio Hasty)
Cc:        msmith@atrad.adelaide.edu.au, terry@lambert.org, freebsd-hackers@freebsd.org
Subject:   Re: video capture driver interface to file system?
Message-ID:  <199704180319.MAA21156@genesis.atrad.adelaide.edu.au>
In-Reply-To: <199704180304.UAA01268@rah.star-gate.com> from Amancio Hasty at "Apr 17, 97 08:04:28 pm"

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Amancio Hasty stands accused of saying:
> 
> Not interested in using write nor any user level api.

Ok, so you want the kernel to do the work for you.  Have a look at
kern/kern_ktrace..c for how ktrace does it; it gets an fd passed in
from userland (which is the right place for manipulating files etc.),
and writes to it.  It also demonstrates using multiple iov entries 
for writing multiple non-contiguous buffers.

> For the purpose of this discussion, what I want to do is when I get a frame
> in a buffer to pass a token to a file system routine to write the buffer
> to disk.  The object is to avoid unnecessarily copying the buffer.

If you don't want to futz around with filesystems, then you need to 
play with bwrite, and you will want to talk to John D. about that.

> 	Amancio

-- 
]] Mike Smith, Software Engineer        msmith@gsoft.com.au             [[
]] Genesis Software                     genesis@gsoft.com.au            [[
]] High-speed data acquisition and      (GSM mobile)     0411-222-496   [[
]] realtime instrument control.         (ph)          +61-8-8267-3493   [[
]] Unix hardware collector.             "Where are your PEZ?" The Tick  [[



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