On Thu, 25 Aug 2005 13:15:33 -0500, Smarduch Mario-CMS063 <[EMAIL PROTECTED]> wrote: > >We've been noticing some TLB issues on 2.4 and 2.6.10 kernels running >on IA64 NUMA architecture. To this end I have some questions regarding >TLB purging, please bare through with the initial introduction. > >IA64 Inst Set Manual points out that propogation of ptc.g across local >cache coherence domains is platform dependent and must be handled by >software. I'm trying to understand how would this work on a ccNUMA and >whether or not software beyond what hw offers to propgate a ptc.ga >(Purte TC bus transaction) is needed.
See platform_global_tlb_purge. On ccNUMA boxes it gets defined to a platform specific routine. On SGI's SN2, platform_global_tlb_purge ends up calling sn2_global_tlb_purge(). That routine works out if the flush is for the current cpu, for a cpu on the same node or for a remote node and handles the flush accordingly. >When a Purge TC global is issued is hardware responsible for keeping the >xaction from completion (TND# >assertion) until the xaction has become visible to all nodes? The platform's tlb purge routine is responsible for synchronization. It must not return to the caller of platform_global_tlb_purge() until the tlb has been flushed on all the target nodes. IOW, software make non-sync hardware look synchronous. - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
