Date: Sat, 22 Dec 2001 02:45:14 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Luigi Rizzo <rizzo@aciri.org> Cc: John Baldwin <jhb@FreeBSD.ORG>, Peter Wemm <peter@wemm.org>, <current@FreeBSD.ORG> Subject: Re: vm_zeropage priority problems. Message-ID: <20011222023741.P5064-100000@gamplex.bde.org> In-Reply-To: <20011221055117.A15321@iguana.aciri.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 21 Dec 2001, Luigi Rizzo wrote: > On Sat, Dec 22, 2001 at 12:46:40AM +1100, Bruce Evans wrote: > > I think pri_native is just an implementation detail which shouldn't > > be used or visible to threads. It used used by the priority propagation > > mechanism to hold the original pri_level. Threads should just use their > > original priority (or a different one if they want to temporarily change > > thier priority). Even pri_level probably shouldn't be used or visible > > to threads. > > the original priority should be somewhere and accessible, > either directly or through some function. Otherwise how > do we know what to pass to tsleep() ? It's whatever the thread set itself. There is no good way of setting this either (vm_pagezero() and poll_idle() hack it into td->td_ksegrp->kg_pri). Userland would use rtprio(2) instead. Unfortunately, this gives priorities in different units than the ones for tsleep(). > In any case I wonder if this is a bug new in -current; -stable > uses three separate data structures for realtime, user and idle tasks > so even specifying the wrong priority in tsleep should not cause > crossing classes there. -current has only one array, hence the > chance of doing the wrong thing. The 3 classes are a design bug in -stable. Crossing classes is sometimes right and 3 classes mainly make it harder and force triplication of code. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011222023741.P5064-100000>