From owner-freebsd-current Thu Dec 20 11:24:25 2001 Delivered-To: freebsd-current@freebsd.org Received: from iguana.aciri.org (iguana.aciri.org [192.150.187.36]) by hub.freebsd.org (Postfix) with ESMTP id 9780A37B41A for ; Thu, 20 Dec 2001 11:24:16 -0800 (PST) Received: (from rizzo@localhost) by iguana.aciri.org (8.11.3/8.11.1) id fBKJOGT08373; Thu, 20 Dec 2001 11:24:16 -0800 (PST) (envelope-from rizzo) Date: Thu, 20 Dec 2001 11:24:15 -0800 From: Luigi Rizzo To: Peter Wemm Cc: current@freebsd.org Subject: Re: vm_zeropage priority problems. Message-ID: <20011220112415.B8230@iguana.aciri.org> References: <20011218160949.B89864@iguana.aciri.org> <20011220191327.9119538CC@overcee.netplex.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20011220191327.9119538CC@overcee.netplex.com.au> User-Agent: Mutt/1.3.23i Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, Dec 20, 2001 at 11:13:27AM -0800, Peter Wemm wrote: ... > Excellent catch! This particular problem was one of the main reasons > why this is still defaulting to 'off'. I have a couple of other changes > to it pending commit to fix some of Bruce's complaints, but I hadn't > noticed the cause of this. > > Part of the problem is that tsleep temporarily elevates the priority for > wakeup, and it is normally returned back to "normal" level when the process > returns to userland (see the *_userpri stuff). ah, ok, kernel threads never return to userland... so, i presume one should also make sure that after the process is scheduled, the priority is restored to the 'native' level; this should also solve the problem with the priority propagation mechanism (though... I have the feeling that if you have nested locks, this cannot scale...) cheers luigi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message