On Tue, Mar 15, 2016 at 1:22 PM, Chong Li <lichong...@gmail.com> wrote: > On Tue, Mar 15, 2016 at 11:41 AM, Dario Faggioli > <dario.faggi...@citrix.com> wrote: >> On Tue, 2016-03-15 at 11:22 -0500, Chong Li wrote: >>> On Mon, Mar 14, 2016 at 5:05 AM, Dario Faggioli >>> <dario.faggi...@citrix.com> wrote: >>> > >> >> We said 'once' and then 'once per domain', but something I'd be fine >> with (coupled with keeping G_WARNING) would be 'once per operation'. >> Basically, if a domain has 128 vcpus, and an hypercall tries to set all >> of them to period=100, budget=50, we just print the warning once. Then, >> if after a while the sysadmin tries the same again, we again just log >> once, etc. >> >> Doing this seems much easier, as the 'warned' flag could just be a >> local variable of the hypercall implementation. I'm quite sure that >> would work if there is not any continuation/re-issueing mechanism in >> the hypercall in question. BUT in our case there is, so things may be >> more complicated... :-/ >> >> Had you thought about a solution like this already? If no, can you see >> whether there is a nice and easy way to make something like what I just >> described above to work in our case? >> > How about: > > We create a global variable in sched_rt.c: > /* This variable holds its value through hyerpcall re-issueing. > * When finding vcpu settings with too low budget or period (e.g, > 100 us), we print a warning > * and set this variable "true". No more warnings are printed > until this variable > * becomes false. > */ > static bool warned; > Initialize it as "false" in rt_init(). > In your example, > we "warned = true" when we find the first vcpu has budget less than > 100 us. Outside > of the while loop, we do: > if ( index == op->u.v.nr_vcpus ) /* no more hypercall re-issueing */ > warned = false; > Hi Chong,
I don't think creating a global variable just for the warning thing is a better idea. Even if we do want such a variable, it should only occur in rt_dom_cntl() function, since it is only used in rt_dom_cntl(). Global variable should be used "globally", isn't it. ;-) Thanks, Meng ----------- Meng Xu PhD Student in Computer and Information Science University of Pennsylvania http://www.cis.upenn.edu/~mengxu/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
