Date: Wed, 1 Dec 2010 15:23:10 -0800 (PST) From: Mark Terribile <materribile@yahoo.com> To: freebsd-questions@freebsd.org Subject: swap pager:indefinite wait buffer: message out of vm.c Message-ID: <552239.98378.qm@web110303.mail.gq1.yahoo.com> In-Reply-To: <20101130120032.B79B010656A4@hub.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi,
Would some kind soul please tell me the meaning of a message coming
from vm.c (FreeBSD 7.2):
"swap pager: indefinite wait buffer: bufobj: 0, blkno: 2, size: 4096"
This message occurs after a return from an msleep whose last args are PSWP,
"swread", and HZ*20 .
When it occurs, some interactive program is locked up. It recovers
sometime later.
My best guess is that this is a complaint that swap or paging I/O has been
excessively delayed. It is occurring while I am running disk-to-disk
transfers that have deep buffering. Think mbuf(1), but it's my own code,
testing some algorithms. I speculate that if the disk queuing/head movement optimization doesn't let the heads move off the file system
where the file resides (and I only see this with large, single files)
then this problem might result. But that is a guess, and speculation.
Does anyone know if this can occur under later versions of FreeBSD?
Thank you for your help.
Mark Terribile
materribile@yahoo.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?552239.98378.qm>