Date: Thu, 27 Jan 2011 23:35:36 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Devin Teske <dteske@vicor.com> Cc: freebsd-hackers@freebsd.org, Mark Saad <nonesuch@longcount.org> Subject: Re: rtld optimizations Message-ID: <20110127213536.GR2518@deviant.kiev.zoral.com.ua> In-Reply-To: <1296162754.20060.42.camel@dt.vicor.com> References: <AANLkTikwHteyqMfMpy_B-AxQ5ZQ_Z3RKhkNpGN23fXtX@mail.gmail.com> <20110125234911.223d8f75@kan.dnsalias.net> <201101271305.21510.naylor.b.david@gmail.com> <AANLkTinkhfso3iRR4pERxhf=%2BnCqy2YDigzgyfNVtnaJ@mail.gmail.com> <20110127203126.GN2518@deviant.kiev.zoral.com.ua> <1296161448.20060.40.camel@dt.vicor.com> <20110127205907.GP2518@deviant.kiev.zoral.com.ua> <1296162754.20060.42.camel@dt.vicor.com>
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--PI2T0JrbAUafY2qi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jan 27, 2011 at 09:12:34PM +0000, Devin Teske wrote: > On Thu, 2011-01-27 at 22:59 +0200, Kostik Belousov wrote: >=20 > > On Thu, Jan 27, 2011 at 08:50:48PM +0000, Devin Teske wrote: > > > Probably did something like this: > > >=20 > > > time sh -c '( firefox & ); sleep 10000000' > > >=20 > > > and then pressed Ctrl-C when he felt that firefox was finished loadin= g. > > > The moment Ctrl-C is pressed, time(1) shows how long it ran up until = you > > > pressed Ctrl-C. > > > NOTE: Pressing Ctrl-C will not terminate the firefox instance. > >=20 > > You cannot have 1/100 of seconds precision with this method. > > This is why I am asking, seeing < 0.1 seconds difference. > > Not to mention some methodical questions, like whether the caches were > > warmed before the measurement by several runs before the actual > > test. >=20 >=20 > Really? >=20 > $ time sh -c '( firefox & ); sleep 10000000' > ^C >=20 > real 0m5.270s > user 0m0.000s > sys 0m0.005s >=20 >=20 > I'd call that 1/100th of a second precision, wouldn't you? >=20 > HINT: Try using bash instead of csh. (I supposed that) obvious point of my mail is that you cannot reliably measure 1/100 second intervals when human interaction is involved. To make it completely obvious: human has to press CTRL-C, I did not mean reading the numbers from display. --PI2T0JrbAUafY2qi Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk1B5SgACgkQC3+MBN1Mb4iyEACcDA+e2npfczgWpJsikfv1yXNA hW4AmgI+O15s0tDj/nW8abxKYCsdbGOD =EDM/ -----END PGP SIGNATURE----- --PI2T0JrbAUafY2qi--
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