thanks... But i was talking in context with Linux 2.6 kernel. Anyways can i have a gud article to read on this topic. also there came another doubt in my mind while reading a paper on "unfied buffering and caching mechanism" by Vivek Pai that : if the page cache is shared between different domains and user level programs so will the different programs use the same copy of page cache to read or they wud copy the data to different page cache and then access. If they use the same copy then what will happen if any particular process want to update the data of the page cache. On 11/20/06, David Howells <dhowells@xxxxxxxxxx> wrote:
gaurav <gaurav1207@xxxxxxxxx> wrote: > sorry but i wanted to know exactly two points : > 1) Is default page cache(means not useing MMAP_SHARED()) is shareable among > different user level process . The pagecache is shared between all processes. If MAP_PRIVATE is used, then pages in a private mapping *may* be shared up until those pages are written to. > 2)Is default page cache(means not useing MMAP_SHARED()) is shareable among > diffrent protection domain(means kernel and user adrress space) > thank you I'm not sure your question makes any sense. The kernel does things *to* the pagecache directly, but doesn't make use of it, unless bits of it are passed as data to various system calls. Also, in general, there's no way of stopping the kernel from trampling on the pagecache at will if it wants to. I believe it differs to the M$ Windows kernel in that respect, if that's what you're thinking of. David -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs
-- Gaurav....
