On 16.01.2012, at 19:38, Raghavendra K T wrote: > On 01/16/2012 07:53 PM, Alexander Graf wrote: >> >> On 16.01.2012, at 15:20, Srivatsa Vaddagiri wrote: >> >>> * Alexander Graf<agraf@xxxxxxx> [2012-01-16 04:57:45]: >>> >>>> Speaking of which - have you benchmarked performance degradation of pv ticket locks on bare metal? >>> >>> You mean, run kernel on bare metal with CONFIG_PARAVIRT_SPINLOCKS >>> enabled and compare how it performs with CONFIG_PARAVIRT_SPINLOCKS disabled for >>> some workload(s)? >> >> Yup >> >>> >>> In some sense, the 1x overcommitcase results posted does measure the overhead >>> of (pv-)spinlocks no? We don't see any overhead in that case for atleast >>> kernbench .. >>> >>>> Result for Non PLE machine : >>>> ============================ >>> >>> [snip] >>> >>>> Kernbench: >>>> BASE BASE+patch >> >> What is BASE really? Is BASE already with the PV spinlocks enabled? I'm having a hard time understanding which tree you're working against, since the prerequisites aren't upstream yet. >> >> >> Alex > > Sorry for confusion, I think I was little imprecise on the BASE. > > The BASE is pre 3.2.0 + Jeremy's following patches: > xadd (https://lkml.org/lkml/2011/10/4/328) > x86/ticketlocklock (https://lkml.org/lkml/2011/10/12/496). > So this would have ticketlock cleanups from Jeremy and > CONFIG_PARAVIRT_SPINLOCKS=y > > BASE+patch = pre 3.2.0 + Jeremy's above patches + above V5 PV spinlock > series and CONFIG_PARAVIRT_SPINLOCKS=y > > In both the cases CONFIG_PARAVIRT_SPINLOCKS=y. > > So let, > A. pre-3.2.0 with CONFIG_PARAVIRT_SPINLOCKS = n > B. pre-3.2.0 + Jeremy's above patches with CONFIG_PARAVIRT_SPINLOCKS = n > C. pre-3.2.0 + Jeremy's above patches with CONFIG_PARAVIRT_SPINLOCKS = y > D. pre-3.2.0 + Jeremy's above patches + V5 patches with CONFIG_PARAVIRT_SPINLOCKS = n > E. pre-3.2.0 + Jeremy's above patches + V5 patches with CONFIG_PARAVIRT_SPINLOCKS = y > > is it performance of A vs E ? (currently C vs E) Since D and E only matter with KVM in use, yes, I'm mostly interested in A, B and C :). Alex _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
