From owner-freebsd-arch Thu Mar 7 16:29:26 2002 Delivered-To: freebsd-arch@freebsd.org Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by hub.freebsd.org (Postfix) with ESMTP id 882BB37B400 for ; Thu, 7 Mar 2002 16:29:22 -0800 (PST) Received: by elvis.mu.org (Postfix, from userid 1192) id 58813AE211; Thu, 7 Mar 2002 16:29:22 -0800 (PST) Date: Thu, 7 Mar 2002 16:29:22 -0800 From: Alfred Perlstein To: Julian Elischer Cc: arch@freebsd.org Subject: Re: Contemplating THIS change to signals. (fwd) Message-ID: <20020308002922.GO26621@elvis.mu.org> References: <20020308002452.GN26621@elvis.mu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020308002452.GN26621@elvis.mu.org> User-Agent: Mutt/1.3.27i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Alfred Perlstein [020307 16:25] wrote: > * Julian Elischer [020307 14:00] wrote: > > > > My suggestion is to remove teh code in issignal() that perfoms the > > blocking actions and create a separate function that does that action. > > I would then call that function from userret() immediatly after the call > > to issignal(). The result would be that > > suspended processes would still not reach userland, but processes would > > not have to option of suspending indefinitly at sleep(). > > You are correct, you can _not_ allow arbitrary kernel threads to > block indefinetly while potentially holding higher level locks. > > Please proceed with your planned work, it seems like the right > thing to do. Both Poul-Henning Kamp and Nate Williams bring up the important point of potentially long running syscalls, there are two ways you might consider fixing this: 1) add an additional flag to msleep to allow suspension during sleep. 2) restart the syscall at the userland boundry. -- -Alfred Perlstein [alfred@freebsd.org] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message