Date: Sat, 8 Feb 2003 23:57:06 -0800 From: Alfred Perlstein <bright@mu.org> To: Peter Wemm <peter@wemm.org> Cc: Jake Burkholder <jake@locore.ca>, Jeff Roberson <jroberson@chesapeake.net>, arch@FreeBSD.ORG Subject: Re: New kernel allocation API Message-ID: <20030209075706.GO88781@elvis.mu.org> In-Reply-To: <20030209074604.EC6962A8B4@canning.wemm.org> References: <20030207234049.A32864@locore.ca> <20030209074604.EC6962A8B4@canning.wemm.org>
next in thread | previous in thread | raw e-mail | index | archive | help
* Peter Wemm <peter@wemm.org> [030208 23:46] wrote: > > And there is hardware support for direct mapping on alpha as well, so it > completely bypasses the TLB entirely for significant benefits. For x86-64 > there'll likely be up to 2^39 of direct mapped space as well, but using 2MB > pages (use an entire level 4 directory slot for direct mapping to avoid the > APTD evilness). We just dont have the space to do this on plain x86 :-(. It seems to me that someone should run some tests to get numbers to determine if the tlb optimization helps more than the kmem-array optimization. However the problem with that is that much more of the kernel should be converted to use zones/slabs before counting on the data gathered. I'm trusting you guys that avoiding the tlb shootdowns help quite a bit, but then again the cost of each free(9) seems quite high. I may see if I can convert some paths in the kernel to use zones. :) -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' 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?20030209075706.GO88781>