Date: Tue, 2 May 2006 11:19:21 -0700 From: "Bharma Ji" <bharmaji@gmail.com> To: freebsd-hackers@freebsd.org Subject: memory allocation / deallocation within the kernel Message-ID: <67beabb0605021119y5770cd3al55e2c875c84589b@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
I am trying to understand the impact of memory allocation / deallocation within the kernel. As I understand a) Kernel memory is not pageable ie the one you get from using kernel malloc(there may be exceptions) b) Does this imply that if I have 1 GB of RAM - then I cannot reserve more than 1 GB of kernel virtual address space? The reason is that if at any point of time, the kernel has to allocate all of its virtual address space i.e. if it needs to allocate more than 1 GB of address space, there won't b= e any physical RAM memory to allocate from and thus this scenario is not allowed as a configuration? c) Another scenario is that assume that the kernel has 512 MB of virtual address space with 1 GB of RAM. Now assume that the entire 1 GB of RAM is used up by the kernel and other userland process that are running - with th= e kernel taking 256 MB and the rest allocated to the processes. Now if the kernel needs to allocate more memory, will some of the processes be swapped out to make way for the kernel(since the kernel can take upto 512 MB) Thanks for any answers. Any URL / literature that explains this will also b= e appreciated.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?67beabb0605021119y5770cd3al55e2c875c84589b>