Izik Eidus wrote: > Izik Eidus wrote: >> Anthony Liguori wrote: >>> Izik Eidus wrote: >>>> this patchs allow the guest not shadowed memory to be swapped out. >>>> >>>> to make it the must effective you should run -kvm-shadow-memory 1 >>>> (witch will make your machine slow) >>>> with -kvm-shadow-memory 1, 3giga memory guest can get to be just >>>> 32mb on physical host! >>>> >>>> when not using -kvm-shadow-memory, i saw 4100mb machine getting to >>>> as low as 168mb on the physical host (not as bad as i thought it >>>> would be, and surely not as bad as it can be with 41mb of shadow >>>> pages :)) >>>> >>> >>> So what exactly does this option do? Is it really worth exposing it >>> as an option if it slows down guests so much? >>> >>> At least, a better name for the option would be nice. >>> >>> Regards, >>> >>> Anthony Liguori >> -kvm-shadow-memory was included in kvm from version 46. >> it control how much pages will be allocated to the shadow cache, >> (from version 46 the default is 2% of the system (so 4.1giga have >> about 80 mbs of shadow cache by default)) >> the problem is that each page that present at the shadow cache ( mmu >> pages ) cant be swapped out, so as lower as the number of shadow >> caches you have as more swappable will be >> useful. >> >> (this option (kvm-shadow-memory) was included to make it possible >> that as less as possible shadow cache memory will be deleated ( >> beacuse it have big overhead to lose this cache) >> > just to make it clearer, > -kvm-shadow-memory main purpose is to speed up the guest, ( as more > mmu pages you have to the shadow cache, as faster as your guest will > be while > it working with alot of memory) > (the main mission is that kvm_free_some_pages() will get called as > less as possible)
Yeah, I realized what -kvm-shadow-memory shortly after I sent my first note :-) Sorry for the noise. Regards, Anthony Liguori ------------------------------------------------------------------------- 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
