Hi! On Thu, Jan 16, 2020 at 05:58:24PM +0000, Christophe Leroy wrote: > On a powerpc8xx, with current powerpc/32 ASM VDSO: > > gettimeofday: vdso: 907 nsec/call > clock-getres-realtime: vdso: 484 nsec/call > clock-gettime-realtime: vdso: 899 nsec/call > > The first patch adds VDSO generic C support without any changes to common > code. > Performance is as follows: > > gettimeofday: vdso: 1211 nsec/call > clock-getres-realtime: vdso: 722 nsec/call > clock-gettime-realtime: vdso: 1216 nsec/call > > Then a few changes in the common code have allowed performance improvement. At > the end of the series we have: > > gettimeofday: vdso: 974 nsec/call > clock-getres-realtime: vdso: 545 nsec/call > clock-gettime-realtime: vdso: 941 nsec/call > > The final result is rather close to pure ASM VDSO: > * 7% more on gettimeofday (9 cycles) > * 5% more on clock-gettime-realtime (6 cycles) > * 12% more on clock-getres-realtime (8 cycles)
Nice! Much better. It should be tested on more representative hardware, too, but this looks promising alright :-) Segher
