Check this out for an overview of the difference between discontigmem and flatmem. http://lkml.org/lkml/2006/2/6/92 me no experts either. just learning. Another on discontiguous memory: http://wikis.sun.com/display/WDD/DMA and its reason: http://www.technovelty.org/linux/bigmemory.html basically your inside dmesg's output the entries for e820 provides the physical memory ranges: BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009f000 (usable) BIOS-e820: 000000000009f000 - 00000000000a0000 (reserved) BIOS-e820: 0000000000100000 - 000000003ffda000 (usable) BIOS-e820: 000000003ffda000 - 0000000040000000 (reserved) BIOS-e820: 00000000e0000000 - 00000000f0007000 (reserved) BIOS-e820: 00000000f0008000 - 00000000f000c000 (reserved) BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved) BIOS-e820: 00000000fed20000 - 00000000fee10000 (reserved) BIOS-e820: 00000000ffb00000 - 0000000100000000 (reserved) plus lots of other goodies as well....check it out. cat /proc/iomem and /proc/meminfo may help as well. I would suggest u compiled with FLATMEM, take all these information, and diff it with DISCONTIGMEM kernel, and see where are the differences.....these should be the cause of your problem. As explained here: http://lse.sourceforge.net/numa/status/description.html DISCONTIGMEM seemed to be used mainly in NUMA scenario. Not sure why are you changing it from FLATMEM to DISCONTIGMEM? More info: http://mail.nl.linux.org/kernelnewbies/2002-05/msg00074.html http://cateee.net/lkddb/web-lkddb/DISCONTIGMEM.html ---> good info. Perhaps what u need is sparsemem: http://lkml.indiana.edu/hypermail/linux/kernel/0607.3/2465.html On Thu, Apr 23, 2009 at 1:31 PM, Adam Jiang <jiang.adam@xxxxxxxxx> wrote: > Hello, > > How can I test if the physical memory initialized correctly? Is there some test > suite for kernel? > > I have encountered some errors in main memory. It seems DMA related functions > don't work well after I change the memory mode from 'FLATMEM' to > 'DISCONTIGMEM'. I wonder how can I confirm the status in kernel. > > How can I get these information in kernel? > 1. the layout of memory > 2. memory mapping > 3. whether the conversion between physical address and virtual address is > correct. > > Would you please help me kindly? Any idea or documents will be appreciate. > > Thanks and best regards, > -- > Adam > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
