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From: "John S. Dyson" <toor@dyson.iquest.net>
Message-Id: <199712221139.GAA01259@dyson.iquest.net>
Subject: Re: Descriptor vectorized read/write?
In-Reply-To: <Pine.BSF.3.96.971222001036.2544A-100000@acroal.com> from "J. Weatherbee - Senior Systems Architect" at "Dec 22, 97 00:35:09 am"
To: jamil@acroal.com (J. Weatherbee - Senior Systems Architect)
Date: Mon, 22 Dec 1997 06:39:43 -0500 (EST)
Cc: hackers@FreeBSD.ORG
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In -current, we have implemented POSIX AIO, it does what you
need.  It is super-efficient on raw devices (I wonder what
that is for??? :-)).


J. Weatherbee - Senior Systems Architect said:
> And in addition to this, has anyone ever though of implement vectorized
> read/write calls that are vectorized across multiple descriptors.  i.e
> reading from multiple descriptors into buffers simultaneously, possibly
> implemented similarily to the way poll(2) is.
> 
> i.e (multiple duplicate fd's with same direction handled the same as
> readv/writev scatter io)
> 
> ---------------------------------------------------------------------------
> 
> void mreadv (const struct miovec *miov, int miovcnt);
> 
>     struct miovec 
>      {
>         int fd; /* file descriptor */ 
>         int err; /* error status/ return count / initially i/o direction
>                   * MREAD/MWRITE */
>         char *base; /* base address */
>         size_t len; /* io length */       
>       };
> ---------------------------------------------------------------------------
> 


-- 
John                  | Never try to teach a pig to sing,
dyson@freebsd.org     | it just makes you look stupid,
jdyson@nc.com         | and it irritates the pig.