From owner-freebsd-threads@FreeBSD.ORG Tue Apr 22 05:55:53 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 EFD5E37B401 for ; Tue, 22 Apr 2003 05:55:53 -0700 (PDT) Received: from mail.pcnet.com (mail.pcnet.com [204.213.232.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id 36DDE43F3F for ; Tue, 22 Apr 2003 05:55:53 -0700 (PDT) (envelope-from eischen@pcnet1.pcnet.com) Received: from pcnet1.pcnet.com (localhost [127.0.0.1]) by mail.pcnet.com (8.12.8/8.12.1) with ESMTP id h3MCtqBg027967; Tue, 22 Apr 2003 08:55:52 -0400 (EDT) Received: from localhost (eischen@localhost)h3MCtpYR027964; Tue, 22 Apr 2003 08:55:52 -0400 (EDT) Date: Tue, 22 Apr 2003 08:55:51 -0400 (EDT) From: Daniel Eischen To: Igor Sysoev In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: threads@freebsd.org Subject: Re: libkse -> libpthread 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: Tue, 22 Apr 2003 12:55:54 -0000 On Tue, 22 Apr 2003, Igor Sysoev wrote: > On Mon, 21 Apr 2003, Daniel Eischen wrote: > > Libpthread can be made to behave the same as libthr just > > by forcing every thread to be scope system. Currently, > > the implementation for scope system threads does have > > a small amount of overhead in that they still get upcalls > > after the thread blocks in the kernel (in this case > > the KSE just reenters the kernel with kse_release() > > and waits for the thread to become unblocked). These > > KSEs also require a small stack separate from the > > thread's stack. The code is in place (in the UTS) to > > not require a separate stack and not get any upcalls > > for these threads, but we just need a bit more > > kernel work to optimize this overhead away. > > But why is not it implemented via setting kse_mailbox.km_curthread to NULL ? > As I understand it's way to disable upcalls when UTS is preempted > by the kernel (the time slice ended, the page in operation, etc.) > i.e. UTS should always run as 1:1 thread. > Had it been changed ? How is UTS protected now ? We can't use this method yet for 1:1 because we don't have a way to redirect a signal to a thread running like this. We need kse_thr_interrupt() to have a signal argument and for the kernel to install the signal frame on the stack of the target thread (or keep it pending on the thread if masked). -- Dan Eischen