Yes, I remembered your suggestion. That is why I suggest to enable a compile option so that somebody can start formal benchmark measurement :-) Eddie
Magenheimer, Dan (HP Labs Fort Collins) wrote: > Rid mangling change has been discussed many times on the list, > most recently: > > http://lists.xensource.com/archives/html/xen-ia64-devel/2005-11/msg00282.html > >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of Xu, >> Anthony Sent: Monday, March 13, 2006 6:37 PM >> To: Dong, Eddie; Tian, Kevin; Akio Takebe; Masaki Kanno; >> xen-ia64-devel@lists.xensource.com >> Subject: RE: [Xen-ia64-devel] [PATCH] [RESEND] domU destroy & page >> ref counter >> >>> From: Dong, Eddie >>> Sent: 2006年3月13日 22:12 >>> A minor suggestion for next in my mind is that we may add a simple >>> COMPILE option in Makefile or some .h file to be able to choice 1/3 >>> byte swap or 1/2 byte swap. People has some thoughts that 1/2 byte >>> swap may have better hash locality. >>> >>> Eddie. >> I second Eddie, >> >> I have some observations about this. >> Usually guest applications use almost the address space, the only >> different is rid. What I observed was if the lowest 17 bits of rid >> are same, the hash address is same. If we swap 1/3 byte, >> applications use the same address space but different rid may have >> the hash address in a majority of situations, which may make some >> collision chains very long. >> >> These are just some observations, I don't mean 1/2 byte swap is >> better than 1/3 byte swap.I think we need to add COMPILE option to >> get benchmark data first, and then make the decision. >> >> It's obviously not a big task but deserve to do. One thing we need >> to pay extra attention is the rid byte swap is done in assembly code >> in some fast_hyperpriops. >> >> Thanks, >> Anthony >> >> _______________________________________________ >> Xen-ia64-devel mailing list >> Xen-ia64-devel@lists.xensource.com >> http://lists.xensource.com/xen-ia64-devel _______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel
