Hi Adhemerval, > This patch implement the time syscall as vDSO. I have a glibc patch > to use it as IFUNC (as latest gettimeofday patch). Below the perf > numbers: > > Baseline PPC32: 380 nsec > Baseline PPC64: 352 nsec > vdso PPC32: 20 nsec > vdso PPC64: 20 nsec
Very nice speedup. One small performance improvement: +1: ld r8,CFG_TB_UPDATE_COUNT(r3) + ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3) + andi. r0,r8,1 /* pending update ? loop */ + bne- 1b Since you are only reading one long you shouldn't need to check the update count and loop, you will always see a consistent value. The system call version of time() just does an unprotected load for example. > I focused on 64 bit kernel, do I need to provide a scheme for 32 bits > as well? > > Any tips, advices, comments? With the above change and with Michael's comments covered (decent changelog entry and Signed-off-by): Acked-by: Anton Blanchard <an...@samba.org> Anton _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
