hello all
i have a sensor driver want to malloc 2.xM SDRAM to capture data(using DMA), so i used remap_pfn_range to malloc 3M.
But in /proc/meminfo, it showes free memory reduce 4M. i also check the /proc/buddyinfo, it seemes too.
(i am looking inside kernel code, but not get clear at now).
is remap_pfn_range should align to 2(n) * (page size) ?
thanks for any hints
zzh