Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [RFC][PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code | Date | Wed, 9 Aug 2006 04:45:16 +0200 |
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On Wednesday 09 August 2006 04:17, john stultz wrote:
> + cycle_t ret; > + rdtscll(ret);
_sync
> +static cycle_t __vsyscall_fn vread_hpet(void) > +{ > + return (cycle_t)readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0); > +}
64bit HPET?
> +extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
No extern in .c please
> +static __always_inline int syscall_gtod(struct timeval *tv, struct timezone *tz) > +{ > + int ret; > + > + asm volatile("syscall"
You eliminated the patching away of the syscall opcode? Please retain that.
> - tv->tv_sec = sec + usec / 1000000; > - tv->tv_usec = usec % 1000000; > + now = __vsyscall_gtod_data.clock.vread(); > + > + base = __vsyscall_gtod_data.clock.cycle_last; > + mask = __vsyscall_gtod_data.clock.mask; > + mult = __vsyscall_gtod_data.clock.mult; > + shift = __vsyscall_gtod_data.clock.shift; > + > + *tv = __vsyscall_gtod_data.wall_time_tv; > + > + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq));
Do you have benchmarks on performance compared to the old code?
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