Date: Mon, 21 Jun 2004 11:29:39 +0800 From: Xin LI <delphij@frontfree.net> To: Robert Watson <rwatson@FreeBSD.org> Cc: current@FreeBSD.org Subject: Re: calcru: negative time ... followed by freeze Message-ID: <20040621032939.GA1909@frontfree.net> In-Reply-To: <Pine.NEB.3.96L.1040620200617.5500D-100000@fledge.watson.org> References: <Pine.NEB.3.96L.1040620200617.5500D-100000@fledge.watson.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--4Ckj6UjgE2iN1+kY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jun 20, 2004 at 08:10:23PM -0400, Robert Watson wrote: >=20 > I've now seen the following scenario happen several times in the last few > days while doing testing and benchmarking: I run a multi-threaded test, > such as super-smack, that causes a moderately high system load. I then > hit Ctrl-T or run top, or some other activity that forces calcru() to > execute. I will not infrequently get an extremely hard hang -- can't get > to DDB using serial break, etc. I don't remember it happening when using > non-threaded apps, so I'm wondering if there's a poor interaction with > KSE/scheduler/who knows what. >=20 > 7:55PM up 6 mins, 2 users, load averages: 1.37, 0.91, 0.43 > USER TTY FROM LOGIN@ IDLE WHAT > root d0 - 7:55PM - w > rwatson p0 cboss 7:50PM 2 super-smack > select-key > hippy# top > calcru: negative time of 1834075 usec for pid 654 (super-smack) > ca~~ >=20 > In this case, I ran super-smack with the following parameters: >=20 > hippy:/usr/tmp/super-smack> super-smack select-key.smack 15 1000 >=20 > This generates 15 workers, which should cause mysql to spawn off threads > as well. I'm running with stock libpthread on this system (slightly old) > but an up-to-date kernel from CVS, GENERIC. >=20 > Has anyone else seen this? I saw calcru: negative time when I am having my system booted with a fresh built kernel and world: %uname -a FreeBSD beastie.frontfree.net 5.2-delphij FreeBSD 5.2-delphij #77: Sun Jun = 20 21:58:10 CST 2004 root@:/usr/obj/usr/src/sys/BEASTIE i386 I have some local kernel modifications, which includes RFC3522 implementation ported from DragonFlyBSD (kern/68110 and some further patch), some filesystem modifications (bin/61981) and a PID allocation algorithm ported from NetBSD. However I believe these changes does not contribute to this situation. Additionally I have noticed that my system would silently freeze when encounting heavy load with HTT enabled. My CPU is Pentium4 2.8-E. It seems that I am not the only one who have problem with P4-2.8E, I think this should be taken into consideration, too. Cheers, --=20 Xin LI <delphij frontfree net> http://www.delphij.net/ See complete headers for GPG key and other information. --4Ckj6UjgE2iN1+kY Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFA1lYjOfuToMruuMARAtCMAJ45AgQhaUzJJRUp/xF4RnblnxCg7QCggUf8 Caaw2fIIIMypkleqVqNXhRI= =ZfdD -----END PGP SIGNATURE----- --4Ckj6UjgE2iN1+kY--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040621032939.GA1909>