> -----Original Message----- > From: Mike Surcouf [mailto:mps.surcouf.lkml@xxxxxxxxx] > Sent: Friday, September 26, 2014 7:53 PM > To: Thomas Shao > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; Olaf Hering; Robo Bot; > jasowang@xxxxxxxxxx; KY Srinivasan; Haiyang Zhang > Subject: Re: [PATCH] Drivers: hv: util: Implement Time Synchronization using > host time sample > > > +/* helper function to call adjtimex command in user mode */ static > > +void run_adjtimex_cmd(s64 tickvalue) { > > + char *argv[4], *envp[3]; > > + char str_tickvalue[20]; > > + > > + sprintf(str_tickvalue, "%lld", tickvalue); > > + > > + argv[0] = "/sbin/adjtimex"; > > + argv[1] = "-t"; > > + argv[2] = str_tickvalue; > > + argv[3] = NULL; > > + > > + envp[0] = "HOME=/"; > > + envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; > > + envp[2] = NULL; > > + > > + call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); } > > > What happens when adjtimex is not present? > Is there no kernel space function for that? > Does this patch affect "not setting correct time on restore" or "not setting > correct time on live migration" bug? > If adjtimex is not present, then the slew time part didn't take effect. There is a kernel space do_adjtmex, but it's only for sys call and not exposed to module. So I didn't use it in my patch. With this patch, it will step the clock if the time drift is larger than 1 seconds, so it can solve the issue your mentioned. And on the other hand, "setting correct time on restore" is already fixed in other patch, which is already in upstream. > Thanks > > Mike _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
