[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] some performance issue of shadow2 on 2.6 Linux VMX and possible fix
On ia32e system, old Linux 2.6 kernel (previous to 2.6.16) shares one l4 page for all processes. At context switch, it replaces old L3 page in l4e with the new one. Current shadow discards old shadow page at the same time. When context switch (e.g. client/server model) is very frequent, it can be a high cost. One solution is to pin L3 page as well as L4 page. It reserves previous process' L3 shadow page for later use. The test shows it benefits benchmark with frequent context switch such as OLTP (server/client), CPU2k (multi users) and specjbb (multi warehouses). But it also introduces some overhead. As L3 page table is pinned, it needs 1+ extra page fault to be unpinned after the process is terminated. KB's performance has some impact. Thanks, Xiaowei Attachment:
sh2.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |