Date: Mon, 31 Dec 2001 23:55:10 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Alfred Perlstein <bright@mu.org> Cc: Michal Mertl <mime@traveller.cz>, Matthew Dillon <dillon@apollo.backplane.com>, <arch@FreeBSD.ORG> Subject: Re: 64 bit counters Message-ID: <20011231234620.O6481-100000@gamplex.bde.org> In-Reply-To: <20011229185917.J16101@elvis.mu.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 29 Dec 2001, Alfred Perlstein wrote: > * Michal Mertl <mime@traveller.cz> [011229 18:49] wrote: > > I doesn't seem too bad to me, but I do have a problem - I can't implement > > real atomic 64 bit operations on an i386. It shouldn't be named atomic_XXX > > if it isn't atomic. So that other people don't start to use it on <586 > > with some variable which changes fast. > > > > What about making the counters not 64 bit, but the size of biggest atomic > > type? Something like type u_maxatomic_t which would be 32 bit on <586 and > > 64 bit otherwise. There would still be problem in determining at compile > > time the size but we could choose the safe size if not somewhere defined > > otherwise. > > > > I can make changes to my local tree but how should I send them someone for > > review? Should I send them to arch? I tried to find the answer to this > > question in developers's handbook but didn't find it. > > *laff* the concept of atomic_t was initially proposed by me over > a year ago (i got the idea from linux) however it never seemed to > get done. atomic_t would be "int" if anything. I removed support for atomic operations on all types except "int" (and some pointers punned to int on i386's), and found that (on i386's) only 2 source files didn't compile. Both are easy to fix (one MD place used a char type for a set of flags that is followed by padding to a 32-bit boundary anyway, and one MI place uses long types which are equivalent to ints on i386's anyway). Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011231234620.O6481-100000>