this patch make kvm dynamicly allocate memory to its mmu pages buffer. untill now kvm used to allocate just 1024 pages ( 4MB ) no matter what was the guest ram size.
beacuse the mmu pages buffer was very small alot of pages that had "correct" information about the guest pte, had to be released. what i did here is the first step to get one or both of the below options: 1)adding support to kvm to increase and decrease at runtime its mmu pages buffer by considering how much times the mmu_free_some_pages function is called. 2)adding support to kvm to share the mmu buffers with all VMs that run, in this case an idle vm will give some of it mmu buffer to "highly working vm" i wrote this patch with this 2 options in mind, and therefor i used lists and not arry, and created each entry of the list 1MB (holding list of 256 pages). it is now very easy and inexpensive to delete/add/move or doing anything we want with this 1MB block. ugly "benchmark" i ran showed that when the guest used 1% of 512mb vm to its mmu buffer and compiled the linux kernel with -j 8 it had number of 21,100,000 fix page_fault exits and it took 8:10 secs when the same guest with the same number of ram used 2% of the 512mb bm to its mmu buffer it compiled the linux kernel with -8 at 7:48 secs and had just 17,500,000 fix page_faults exits. (as far as the guest will have more ram the results should be much faster than without this patch) (this benchmark was really ugly, i didnt use ram drive or anything like that to compiling it..) ohh, i must to add that i added a function to remove the lists and all the pages it allocated to the mmu pages, but i didnt write any line in it because i want to ask avi something first, so dont blame me for stealing your ram :) anyway enjoy. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
