[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [V9 2/3] Refactor rangeset structure for better performance.
>>> On 31.12.15 at 10:33, <yu.c.zhang@xxxxxxxxxxxxxxx> wrote: > On 12/21/2015 10:38 PM, Jan Beulich wrote: >>>>> On 15.12.15 at 03:05, <shuai.ruan@xxxxxxxxxxxxxxx> wrote: >>> This patch refactors struct rangeset to base it on the red-black >>> tree structure, instead of on the current doubly linked list. By >>> now, ioreq leverages rangeset to keep track of the IO/memory >>> resources to be emulated. Yet when number of ranges inside one >>> ioreq server is very high, traversing a doubly linked list could >>> be time consuming. With this patch, the time complexity for >>> searching a rangeset can be improved from O(n) to O(log(n)). >>> Interfaces of rangeset still remain the same, and no new APIs >>> introduced. >> >> So this indeed addresses one of the two original concerns. But >> what about the other (resource use due to thousands of ranges >> in use by a single VM)? IOW I'm still unconvinced this is the way >> to go. > > Thank you, Jan. As you saw in patch 3/3, the other concern was solved > by extending the rangeset size, which may not be convictive for you. > But I believe this patch - refactoring the rangeset to rb_tree, does > not only solve XenGT's performance issue, but may also be helpful in > the future, e.g. if someday the rangeset is not allocated in xen heap > and can have a great number of ranges in it. :) I don't follow: Patch 3 makes things worse resource consumption wise, not better. Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |