Re: kernel page size explanation

2005-07-25 Thread Valdis . Kletnieks
On Mon, 25 Jul 2005 19:12:47 +0530, VASM said: > are there any specific reasons for not using large page size for > userspace processes Assume you can use 4K or 4M page sizes. Compute the total memory usage for a system that has 50 processes running, each 1556K in size pgpcU7vVX9g8Z.pgp De

Re: kernel page size explanation

2005-07-25 Thread VASM
On 7/25/05, Nix <[EMAIL PROTECTED]> wrote: > On Mon, 25 Jul 2005, VASM wrote: > > i had one question > > does the linux kernel support only one default page size even if the > > processor on which it is working supports multiple ? > > No. Some architectures have compile-time support for multiple d

Re: kernel page size explanation

2005-07-24 Thread Nix
On Mon, 25 Jul 2005, VASM wrote: > i had one question > does the linux kernel support only one default page size even if the > processor on which it is working supports multiple ? No. Some architectures have compile-time support for multiple different page sizes (e.g. Itanium, SPARC64); many have

Re: kernel page size explanation

2005-07-24 Thread Fawad Lateef
On 7/25/05, VASM <[EMAIL PROTECTED]> wrote: > i had one question > does the linux kernel support only one default page size even if the > processor on which it is working supports multiple ? > The PAGE_SIZE depends on the architecture and it do supports different page_sizes depending on the archi

Re: kernel page size explanation

2005-07-24 Thread VASM
i had one question does the linux kernel support only one default page size even if the processor on which it is working supports multiple ? On 7/25/05, Nix <[EMAIL PROTECTED]> wrote: > On 22 Jul 2005, Jesper Juhl suggested tentatively: > > You can > > A) look in the .config file for your curren

Re: kernel page size explanation

2005-07-24 Thread Nix
On 22 Jul 2005, Jesper Juhl suggested tentatively: > You can > A) look in the .config file for your current kernel (if your arch > supports different page sizes at all). > B) You can use the getpagesize(2) syscall at runtime. getpagesize() > returns the nr of bytes in a page - man getpagesize -

Re: kernel page size explanation

2005-07-23 Thread Gaspar Bakos
Hi, Jesper, RE: > > 2. how can one tune it (for 2.6.*)? > > For some archs the page size can be set at compile-time with > CONFIG_PAGE_SIZE_4KB, CONFIG_PAGE_SIZE_8KB etc - mips is an example of > such an arch (also take a look at CONFIG_HUGETLB_PAGE and friends). OK, now i figured it out. On AMD

Re: kernel page size explanation

2005-07-21 Thread Jesper Juhl
On 7/22/05, Gaspar Bakos <[EMAIL PROTECTED]> wrote: > Hi, > > Sorry for this nursery-school question. > > Could someone briefly explain me : > 1. what is the kernel page size (any _useful_ pointer on the web is fine), Depends on arch. Take a look at PAGE_SIZE and PAGE_SHIFT - look in include/asm

Re: kernel page size explanation

2005-07-21 Thread Robert Hancock
Gaspar Bakos wrote: Hi, Sorry for this nursery-school question. Could someone briefly explain me : 1. what is the kernel page size (any _useful_ pointer on the web is fine), 2. how can one tune it (for 2.6.*)? 3. what kind of effect does it have on system performance, if it is tuneable, and if

kernel page size explanation

2005-07-21 Thread Gaspar Bakos
Hi, Sorry for this nursery-school question. Could someone briefly explain me : 1. what is the kernel page size (any _useful_ pointer on the web is fine), 2. how can one tune it (for 2.6.*)? 3. what kind of effect does it have on system performance, if it is tuneable, and if it worth changing this