search for: pvclock_read_retri

Dereferencing gtod->cycle_last all over the place and foing the cycles < last comparison in the vclock read functions generates horrible code. Doing it at the call site is much better and gains a few cycles both for TSC and pvclock. Caveat: This adds the comparison to the hyperv vclock as well, but I have no way to test that. Signed-off-by: Thomas Gleixner <tglx at linutronix.de> ---

The code flow for the vclocks is convoluted as it requires the vclocks which can be invalidated separately from the vsyscall_gtod_data sequence to store the fact in a separate variable. That's inefficient. Restructure the code so the vclock readout returns cycles and the conversion to nanoseconds is handled at the call site. If the clock gets invalidated or vclock is already VCLOCK_NONE,

Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime() implementation, which extended the clockid switch case and added yet another slightly different copy of the same code. Especially the extended switch case is problematic as the compiler tends to generate a jump table which then requires to use retpolines. If jump tables are disabled it adds yet another conditional to the existing

Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime() implementation, which extended the clockid switch case and added yet another slightly different copy of the same code. Especially the extended switch case is problematic as the compiler tends to generate a jump table which then requires to use retpolines. If jump tables are disabled it adds yet another conditional to the existing

Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime() implementation, which extended the clockid switch case and added yet another slightly different copy of the same code. Especially the extended switch case is problematic as the compiler tends to generate a jump table which then requires to use retpolines. If jump tables are disabled it adds yet another conditional to the existing