From owner-freebsd-hackers Sun Apr 11 18:29:27 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from lestat.nas.nasa.gov (lestat.nas.nasa.gov [129.99.50.29]) by hub.freebsd.org (Postfix) with ESMTP id 0A2BD14E21 for ; Sun, 11 Apr 1999 18:29:25 -0700 (PDT) (envelope-from thorpej@lestat.nas.nasa.gov) Received: from lestat (localhost [127.0.0.1]) by lestat.nas.nasa.gov (8.8.8/8.6.12) with ESMTP id SAA25072; Sun, 11 Apr 1999 18:27:05 -0700 (PDT) Message-Id: <199904120127.SAA25072@lestat.nas.nasa.gov> To: John Milford Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: read() and pread() syscalls Reply-To: Jason Thorpe From: Jason Thorpe Date: Sun, 11 Apr 1999 18:27:04 -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 11 Apr 1999 18:10:45 -0700 John Milford wrote: > Yeah, I sort let that slip by me. However the concept of > emulating read() with readv() and pread() with preadv() does seem > valid. I originally was looking at emulating read() with readv() > from userspace, but when pread showed up it looked like a better > match, unfortuantely I didn't look close enough. It would appear that > there is no efficiency trade off in a read() to readv() user space > conversion since the kernel essentially does the convertion internally > anyway. ...and since you must provide the old syscall stubs for binary compatibility, and the read() interface is much easier for some things to deal with (e.g. assembly language), "what's the point"? Just share as much of the in-kernel code as you can. -- Jason R. Thorpe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message