Hi, Please CMIIW. On 32bit systems: Regarding ZONE_HIMEM which is 128MB virtual memory in size. With kmap you can address using this 128MB of virtual memory, any physical memory from 0-4GB that is not used by ZONE_DMA and ZONE_NORMAL. However, i am not sure why you would want to address this whole 0-4GB range and not a predetermined 128MB physical range since different devices in the kernel can only use the same 128MB (it is not replaced as with processes when there is a context switch). I.e., a device has to release the memory almost immediately and certainly before another device needs that memory. I can only guess that the reason is some weird devices that can only access specific physical memory ranges for DMA transfers. Though, what happens if a process captured that range? it would have to be vacated first to be mapped to. Plus, how ZONE_HIMEM applies when you have under 896MB, over 896MB and 4GB RAM, does it even matter? can a mapped ZONE_HIMEM physical memory be swapped? As i understand it, if RAM is under 896MB, since ZONE_NORMAL uses logical mappings it will mean the ZONE_NORMAL will be lower than 896MB, how much is determined how? and ZONE_HIMEM, perhaps non-existant? 10x. -- Regards, Tzahi. -- Tzahi Fadida Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info WARNING TO SPAMMERS: see at http://members.lycos.co.uk/my2nis/spamwarning.html -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
