Date: Thu, 25 Jan 2018 17:52:57 +0100 From: Hartmut Brandt <hartmut.brandt@dlr.de> To: <hackers@freebsd.org> Subject: allocating large piece of contiguous kernel memory Message-ID: <alpine.BSF.2.20.1801251747460.70702@KNOP-BEAGLE.kn.op.dlr.de>
next in thread | raw e-mail | index | archive | help
Hi all, for a device driver communicating with an FPGA I would like to allocate an 8GByte piece or two 4GByte pieces of contiguous memory in the device driver. The machine is amd64 and has 256GByte. The maximum I can allocate is 512MByte. If I try more (in one piece or in two pieces) contigfree() crashes in pmap_resident_count_dec() with an "pmap resident count underflow". Is this something which is not supposed to work? Or is there something tunable or is this a bug? Regards, harti
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.20.1801251747460.70702>