2010/7/15 Kostik Belousov <kostik...@gmail.com>: > On Thu, Jul 15, 2010 at 08:24:53PM +0530, kalash nainwal wrote: >> On Thu, Jul 15, 2010 at 5:41 PM, John Baldwin <j...@freebsd.org> wrote: >> > On Thursday, July 15, 2010 6:28:53 am kalash nainwal wrote: >> >> Hi, >> >> >> >> I want to allocate one (or more) pages in kernel space. >> >> I'm not sure what is the api in freebsd (something which >> >> is similar to __get_free_pages() of linux). >> >> >> >> Would malloc(4096, ...) guarantee that the returned >> >> address is aligned on page boundary? >> > >> > Well, malloc(PAGE_SIZE) will align it on a page boundary. :) malloc(4096) >> > will be aligned on a 4096-byte boundary if PAGE_SIZE is >= 4096. My >> > understanding is that objects returned from malloc() are aligned to the >> > smallest power-of-2 value >= the requested size up to a page. Allocations >> > larger than a page are page aligned. So a malloc of 24 bytes or 32 bytes >> > is >> > 32-byte aligned for example. >> > >> >> Thanks John for explaining. >> >> After going through the kernel src I was not sure about >> malloc, as the code is little hard to follow. However I figured >> kmem_alloc(kernel_pmap, PAGE_SIZE) would serve my > ^^^^^^kernel_map.
oops. my bad. thanks for correcting. _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
