From owner-freebsd-threads@FreeBSD.ORG Sat Nov 29 21:26:50 2003 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 783C016A4CE for ; Sat, 29 Nov 2003 21:26:50 -0800 (PST) Received: from mail.chesapeake.net (chesapeake.net [208.142.252.6]) by mx1.FreeBSD.org (Postfix) with ESMTP id 274FA43FCB for ; Sat, 29 Nov 2003 21:26:47 -0800 (PST) (envelope-from jroberson@chesapeake.net) Received: from localhost (jroberson@localhost) by mail.chesapeake.net (8.11.6/8.11.6) with ESMTP id hAU5Qet01099; Sun, 30 Nov 2003 00:26:40 -0500 (EST) (envelope-from jroberson@chesapeake.net) Date: Sun, 30 Nov 2003 00:26:40 -0500 (EST) From: Jeff Roberson To: "Christopher M. Sedore" In-Reply-To: <32A8B2CB12BFC84D8D11D872C787AA9A515DAE@EXCHANGE.forest.maxwell.syr.edu> Message-ID: <20031130002541.F4201-100000@mail.chesapeake.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: threads@freebsd.org Subject: Re: KSE system scope vs non system scope threads X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Nov 2003 05:26:50 -0000 On Sat, 29 Nov 2003, Christopher M. Sedore wrote: > > I have a fairly simple question about KSE threads: In a threaded program using KSE threads, what is the effective difference between a system-scope thread and a non-system-scope thread? If I understand the KSE architecture correctly, there should not be a significant functional difference. If my reading lead me to the right conclusion, at the nitty-gritty level, there are multiple KSE groups created with system-scope threads, as I understand it, meaning that the kernel scheduler actually does the scheduling work for system-scope threads, instead of the userland KSE scheduler. > > I ask this because I'm observing some behavior that I don't expect. When running a threaded program with KSE and non-system-scope threads, I see performance degradation in my network traffic when I'm attempting to connect to remote hosts that are down. Libthr doesn't see this degradation, and KSE with system-scope threads doesn't perform as well as libthr, but is much closer. Can you describe the threaded application some? For certain types of tasks thr is likely to remain faster due to its simplicity. I'm mostly just curious to hear what your observations are. Thanks, Jeff > > If there is a canonical document that describes all this, a pointer would be very welcome. > > -Chris > _______________________________________________ > freebsd-threads@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-threads > To unsubscribe, send any mail to "freebsd-threads-unsubscribe@freebsd.org" >