From owner-freebsd-hackers Mon Sep 13 22: 3:23 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from scam.xcf.berkeley.edu (scam.XCF.Berkeley.EDU [128.32.43.201]) by hub.freebsd.org (Postfix) with SMTP id 423FE1516C for ; Mon, 13 Sep 1999 22:02:58 -0700 (PDT) (envelope-from nordwick@scam.xcf.berkeley.edu) Received: (qmail 40382 invoked by uid 27268); 14 Sep 1999 05:02:40 -0000 Message-ID: <19990914050240.40381.qmail@scam.xcf.berkeley.edu> To: freebsd-hackers@freebsd.org Subject: aio_* MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <40380.937285360.1@scam.XCF.Berkeley.EDU> Date: Mon, 13 Sep 1999 22:02:40 -0700 From: "Jayson Nordwick" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG While reading through (at least trying to... I wish there was some sort of kernel documentation available, the entry fee is very high) the aio_* calls, I had a few questions to clear up my understanding: 1) Do they only work on files? The only implementation I see is in the VFS layer. 2) It is my understanding that it uses an aio daemon running as a kernel thread (the aio_daemon() call kind of give that one away). It seems as if this can be almost entirely done in user space. More important to what I am trying to do, it seems as if aio_* does not give peak latency or throughput performace, since the aio_daemon has to compete for resources along with all other processes. Should aio_* be used for applications that have high performance requirements? What does aio_* get you above having a seperate thread pumping in/out data? -jason To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message