Date: Thu, 22 Mar 2001 15:47:02 -0800 (PST) From: Matthew Jacob <mjacob@feral.com> To: John Baldwin <jhb@FreeBSD.org> Cc: arch@FreeBSD.org Subject: Re: Critical Regions Round II Message-ID: <Pine.LNX.4.21.0103221539400.14792-100000@zeppo.feral.com> In-Reply-To: <XFMail.010322153200.jhb@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 22 Mar 2001, John Baldwin wrote: > > On 22-Mar-01 Matthew Jacob wrote: > > > > critical_enter/critical_exit seem fine, but you can save yourself some > > compiler space by just having it return a void *. > > So far critical_t is a register_t on all arch's it is implemented on so far. > Well, it probably should be a register_t, I think I'm using __uint32_t and > the like right now: > > x86: > /* Critical section value */ > typedef __uint32_t critical_t; > > alpha: > /* Critical section value */ > typedef __uint32_t critical_t; > > ia64: > /* Critical section value */ > typedef __uint64_t critical_t; > > Hrm, is a ldq any different from a ldl to the alpha? Umm... yup... 8 bytes instead of 4... > If ldq is faster I could > make it be a register_t (and thus a __int64_t). I'll probably change it to > register_t on x86 and ia64 as it simply holds the saved value of a register > (eflags on x86, psr on ia64). I don't think the speed is an issue either way. > > > What's wrong with alpha having > > > > disable_intr() calls MD/platform function that disables mainbridge > ints > > enable_intr() calls MD/platform function that enables mainbridge ints > > > > I believe that this actually is possible. > > That's fine, however, with this change, disable/enable_intr() are actually > called in very few places. Mostly in trap() on x86 due to hacks to work around > Cyrix bugs, and in configure(). Everything else uses critical_*. > > Well, the joy driver needs fixing (it should use critical_*) as does the bktr > driver. The x86 pcvt driver is also obnoxious, but its x86 specific, and the > pc98 spkr and dma drivers should be using critical_* so that they work in a > nested fashion. Hmm, and x86 profiling, though again, that can use critical_*. > Kernel x86 profiling with SMP is broken in lots of interesting ways. Let's put it this way...if I have to solve what appear to be obscure bugs by disabling interrupts in the alpha MD code somewhere, I'll instantiate such a function (again) if it's no longer there. 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?Pine.LNX.4.21.0103221539400.14792-100000>