On Thu, Sep 05, 2024 at 06:55:27PM +0200, Christophe Leroy wrote: > > > Le 05/09/2024 à 18:13, Jason A. Donenfeld a écrit : > >> +/* > >> + * The macro sets two stack frames, one for the caller and one for the callee > >> + * because there are no requirement for the caller to set a stack frame when > >> + * calling VDSO so it may have omitted to set one, especially on PPC64 > >> + */ > >> + > >> +.macro cvdso_call funct > >> + .cfi_startproc > >> + PPC_STLU r1, -PPC_MIN_STKFRM(r1) > >> + .cfi_adjust_cfa_offset PPC_MIN_STKFRM > >> + mflr r0 > >> + PPC_STLU r1, -PPC_MIN_STKFRM(r1) > >> + .cfi_adjust_cfa_offset PPC_MIN_STKFRM > >> + PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1) > >> + .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF > >> + get_datapage r8 > >> + addi r8, r8, VDSO_RNG_DATA_OFFSET > >> + bl CFUNC(DOTSYM(\funct)) > >> + PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1) > >> + cmpwi r3, 0 > >> + mtlr r0 > >> + addi r1, r1, 2 * PPC_MIN_STKFRM > >> + .cfi_restore lr > >> + .cfi_def_cfa_offset 0 > >> + crclr so > >> + bgelr+ > >> + crset so > >> + neg r3, r3 > >> + blr > >> + .cfi_endproc > >> +.endm > > > > You wrote in an earlier email that this worked with time namespaces, but > > in my testing that doesn't seem to be the case. > > Did I write that ? I can't remember and neither can I remember testing > it with time namespaces. It's possible I confused you with someone else? Hum. Anyway... > > From my test harness [1]: > > > > Normal single thread > > vdso: 25000000 times in 12.494133131 seconds > > libc: 25000000 times in 69.594625188 seconds > > syscall: 25000000 times in 67.349243972 seconds > > Time namespace single thread > > vdso: 25000000 times in 71.673057436 seconds > > libc: 25000000 times in 71.712774121 seconds > > syscall: 25000000 times in 66.902318080 seconds > > > > I'm seeing this on ppc, ppc64, and ppc64le. > > What is the command to use to test with time namespace ? Look at the C in the commit I linked.
