Date: Thu, 30 May 2002 12:19:15 -0700 (PDT) From: Doug White <dwhite@resnet.uoregon.edu> To: Tom Tang <tangj@cs.ucdavis.edu> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: KLD mmap question Message-ID: <20020530121826.D71308-100000@resnet.uoregon.edu> In-Reply-To: <Pine.LNX.4.33.0205301209280.6101-100000@pc1.cs.ucdavis.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 30 May 2002, Tom Tang wrote: > I have a question about implementing mmap functions in > device drivers. Thinking it would be simple, I contigmalloc'd > a buffer of PAGE_SIZE and returned it using atop like other > mmap device implementations. However when my userland program > mmaps the device with offset 0, when I try accessing the returned > pointer, it returns me invalid memory address. Any help would > be appreciated... Generally, after the machine is started, memory gets too fragmented to use contigmalloc. If you preload the module and do the contigmalloc at attach time it should succeed. Doug White | FreeBSD: The Power to Serve dwhite@resnet.uoregon.edu | www.FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020530121826.D71308-100000>