On 14/01/2020 20:35, Andrew Cooper wrote:
Xen inherited its list infrastructure from Linux. One area where has fallen behind is that of prefetching, which as it turns out is a performance penalty in most cases. Prefetch of NULL on x86 is now widely measured to have glacial performance properties, and will unconditionally hit on every hlist use due to the termination condition. Cross-port the following Linux patches: 75d65a425c (2011) "hlist: remove software prefetching in hlist iterators" e66eed651f (2011) "list: remove prefetching from regular list iterators" c0d15cc7ee (2013) "linked-list: Remove __list_for_each" to Xen, which results in the following net diffstat on x86: add/remove: 0/1 grow/shrink: 27/83 up/down: 576/-1648 (-1072) (The code additions comes from a few now-inlined functions, and slightly different basic block padding.) No functional change. Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Acked-by: Julien Grall <jul...@xen.org> Cheers, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
