Date: Tue, 15 Mar 2011 09:19:58 +0300 From: Maxim Dounin <mdounin@mdounin.ru> To: Jung-uk Kim <jkim@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r219653 - in head/sys: arm/include i386/include Message-ID: <20110315061957.GD99496@mdounin.ru> In-Reply-To: <201103142330.p2ENUEL8014903@svn.freebsd.org> References: <201103142330.p2ENUEL8014903@svn.freebsd.org>
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Hello! On Mon, Mar 14, 2011 at 11:30:14PM +0000, Jung-uk Kim wrote: > Author: jkim > Date: Mon Mar 14 23:30:14 2011 > New Revision: 219653 > URL: http://svn.freebsd.org/changeset/base/219653 > > Log: > Make get_cyclecount(9) little bit more useful where binuptime(9) is used. get_cyclecount(9) is for random harvesting, and dropping half of it's entropy in binuptime() case may not be a good idea. It's probably better to fix manpage instead, to clarify it's intended usage. Maxim Dounin > > Modified: > head/sys/arm/include/cpu.h > head/sys/i386/include/cpu.h > > Modified: head/sys/arm/include/cpu.h > ============================================================================== > --- head/sys/arm/include/cpu.h Mon Mar 14 23:19:04 2011 (r219652) > +++ head/sys/arm/include/cpu.h Mon Mar 14 23:30:14 2011 (r219653) > @@ -16,7 +16,7 @@ get_cyclecount(void) > struct bintime bt; > > binuptime(&bt); > - return (bt.frac ^ bt.sec); > + return ((uint64_t)bt.sec << 56 | bt.frac >> 8); > > } > #endif > > Modified: head/sys/i386/include/cpu.h > ============================================================================== > --- head/sys/i386/include/cpu.h Mon Mar 14 23:19:04 2011 (r219652) > +++ head/sys/i386/include/cpu.h Mon Mar 14 23:30:14 2011 (r219653) > @@ -67,7 +67,7 @@ void swi_vm(void *); > * Return contents of in-cpu fast counter as a sort of "bogo-time" > * for random-harvesting purposes. > */ > -static __inline u_int64_t > +static __inline uint64_t > get_cyclecount(void) > { > #if defined(I486_CPU) || defined(KLD_MODULE) > @@ -75,7 +75,7 @@ get_cyclecount(void) > > if (!tsc_present) { > binuptime(&bt); > - return (bt.frac ^ bt.sec); > + return ((uint64_t)bt.sec << 56 | bt.frac >> 8); > } > #endif > return (rdtsc()); > _______________________________________________ > svn-src-all@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/svn-src-all > To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"
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