On 02/08/2012 09:53 AM, Nitin Gupta wrote: > vmap() is not just slower but also does memory allocations at various > places. Under memory pressure, this may cause failure in reading a > stored object just because we failed to map it. Also, it allocates VA > region each time its called which is a real big waste when we can simply > pre-allocate 2 * PAGE_SIZE'ed VA regions (per-cpu). Yeah, vmap() is a bit heavy-handed. I'm just loathe to go mucking around in the low-level pagetables too much. Just seems like there'll be a ton of pitfalls, like arch-specific TLB flushing, and it _seems_ like one of the existing kernel mechanisms should work. I guess if you've exhaustively explored all of the existing kernel mapping mechanisms and found none of them to work, and none of them to be in any way suitably adaptable to your use, you should go ahead and roll your own. I guess you do at least use alloc_vm_area(). What made map_vm_area() unsuitable for your needs? If you're remapping, you should at least be guaranteed not to have to allocate pte pages. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>