Hi Thomas, On 15/04/2019 10:51, Thomas Gleixner wrote: > On Mon, 15 Apr 2019, Huw Davies wrote: > >> On Sun, Apr 14, 2019 at 12:53:32PM +0200, Thomas Gleixner wrote: >>> So it stays in the same cache line, but as we move the VDSO to generic >>> code, the mask field needs to stay and this will make >>> basetime[CLOCK_MONOTONIC] >>> overlap into the next cache line. >> >> Thanks for the great review; this is a good point. >> >>> See >>> https://lkml.kernel.org/r/alpine.deb.2.21.1902231727060.1...@nanos.tec.linutronix.de >>> for an alternate solution to this problem, which avoids this and just gives >>> CLOCK_MONOTONIC_RAW a separate storage space alltogether. >> >> I can certainly do this for the x86 vdso. Would that be useful or >> should I wait for Vincenzo's work on the generic vdso first? > > Depends. If Vincenzo comes along with his new version soon, then you might > get this for free :) > > Vincenzo, what's the state of your work? >
I am mostly done with the development, the only thing missing is the integration of the generic update_vsyscall. After this is complete, I will need to do some testing and extract the performance numbers. Considering that I will be on Easter holiday from this Wednesday till the end of April, I think v6 will be ready around second week of May. > Thanks, > > tglx > -- Regards, Vincenzo