From owner-freebsd-current Mon Feb 11 19:45:55 2002 Delivered-To: freebsd-current@freebsd.org Received: from newman2.bestweb.net (newman2.bestweb.net [209.94.102.67]) by hub.freebsd.org (Postfix) with ESMTP id 1FE3437B50C for ; Mon, 11 Feb 2002 18:18:45 -0800 (PST) Received: from okeeffe.bestweb.net (okeefe.bestweb.net [209.94.100.110]) by newman2.bestweb.net (Postfix) with ESMTP id 495982313D; Mon, 11 Feb 2002 21:17:48 -0500 (EST) Received: by okeeffe.bestweb.net (Postfix, from userid 0) id 789399F136; Mon, 11 Feb 2002 21:12:27 -0500 (EST) Date: Sat, 09 Feb 2002 10:50:42 -0500 (EST) From: John Baldwin To: Julian Elischer Subject: RE: cred stuff.. Cc: current@freebsd.org Message-Id: <20020212021227.789399F136@okeeffe.bestweb.net> 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 09-Feb-02 Julian Elischer wrote: > John, (peter? others?) > > How is it that getting a ucred reference is guarded by PROC_LOCK(p) > but freeing it is guarded by mtx_lock(&Giant); > ? > > Call me naive, but shouldn't they be guarded by the same thing? Naive, maybe. :-P The actual refcount for a ucred is protected by an internal mutex. The PROC_LOCK is to ensure that the value of p_ucred is up to date and doesn't change so that the cred doesn't get free'd out from under us. Giant is needed for crfree() since it can call free(). > Julian > > > On Fri, 8 Feb 2002, Julian Elischer wrote: > >> I'm a little worried about invariants because the behaviour when >> INVARIANTS is set wil be different to teh behaviour when it is off, which >> is 'strange' to say the least. Normally the behaviour si the same but you >> just check for invariant conditions. >> >> >> On Fri, 8 Feb 2002, John Baldwin wrote: >> >> > >> > On 08-Feb-02 Julian Elischer wrote: >> > > >> > > I'd like to commit the code to keep the ucred across userland, >> > > with the code to clear it to NULL kept under DEBUG ifdefs. >> > >> > Use INVARIANTS for the ifdef macro name, but sure. >> > >> > -- >> > >> > John Baldwin <>< http://www.FreeBSD.org/~jhb/ >> > "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ >> > >> >> >> To Unsubscribe: send mail to majordomo@FreeBSD.org >> with "unsubscribe freebsd-current" in the body of the message >> > -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message