On Thu, 25 Feb 2010, Zenek wrote: > my kernel driver gets a userspace pointer to a memory area (virtually > contiguous), allocated by userspace. I would like to use that memory in a > vmalloc-like manner, i.e. I want it to be: Its already virtually mapped for the process. The kernel can access the data. > I will be writing to it using the CPU only, in kernel mode. Thats possible already. > I understand that: > - no page pinning is required (as only the CPU will be writing to that > area) Page pinning is required if the access from the kernel is asynchrononous to user space. > There will be no multithreaded access to that memory. The kernel and userspace are not concurrently accessing the memory? > If the userspace free()s the memory, I still have the pages unless I > vunmap() them, right? If you increase the page count then you still have the pages. The virtual mapping goes away with the process. > How should I go about it? Get the user's vm_area_struct, go through all > the pages, construct an array of struct *page and vmap it? Do a get_user_pages() on the range? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>