> On Sep 14, 2018, at 7:27 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > > On Fri, 14 Sep 2018, Andy Lutomirski wrote: >>> On Sep 14, 2018, at 5:50 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: >>> >>> With the storage array in place it's now trivial to support CLOCK_TAI in >>> the vdso. Instead of extending the array to accomodate CLOCK_TAI, make use >>> of the fact that: >>> >>> - CLOCK ids are set in stone >>> - CLOCK_THREAD_CPUTIME is never going to be supported in the VDSO so >>> the array slot 3 is unused >>> - CLOCK_TAI is id 11 which results in 3 when masked with 0x3 >>> >>> Add the mask to the basetime array lookup and set up the CLOCK_TAI base >>> time in update_vsyscall(). >> >> That’s... horrible. In an amazing way. Can you add BUILD_BUG_ON somewhere >> to assert that this actually works? > > Sure, but changing any of the clock ids will cause more wreckage than that. > I’m more concerned that we add a new one and break the magic masking. Maybe two start sharing the same slot. > Thanks, > > tglx _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
