Date: Sat, 21 Sep 2002 06:50:09 +0200 From: Christian Zander <zander@minion.de> To: "M. Warner Losh" <imp@bsdimp.com> Cc: dominic_marks@btinternet.com, jamie@jamiesdomain.org.uk, freebsd-hackers@FreeBSD.ORG Subject: Re: Kernel - Modules and Compiled in Message-ID: <20020921065009.S4788@chronos> In-Reply-To: <20020921.004207.103236464.imp@bsdimp.com> References: <001001c25d36$a3672be0$83bf83d5@BONG> <20020915203835.GA3497@gallium> <20020921.004207.103236464.imp@bsdimp.com>
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On Sat, Sep 21, 2002 at 12:42:07AM -0600, M. Warner Losh wrote: > > this is false. If you load the module from the boot loader there > is no difference between that and having it be actually compiled > into the kernel in terms of resource allocation. > > However, this is true if you intend to load the drivers at some > time later than boot. > Maybe it helps to get an idea of what memory allocation sizes we are talking about for the NVIDIA driver. For every single OpenGL client in the system memory case (no AGP), the resource manager has to allocate ~1MB (in multiple chunks; 258, 1, 8 pages). > Actually, this issues get gross in a hurry, which is why no one > has done it. :-( > There is a similar interface on Linux, the bigphys patch; it is really only useful to set aside larger chunks of contiguous physical memory for special-case drivers rather than for daily life. Allocating dynamically from a static block of memory set aside a boot time would quickly grow into a major pain for this specific driver due to the numerous smaller allocations. This works well enough for AGP memory since all AGP allocations are much larger (258, 2304 pages) and sized in multiples of 1MB. Even in the AGP memory case, several pages of DMA memory need to be allocated from general system memory. -- christian zander zander@minion.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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