Date: Wed, 9 Jan 2008 12:06:26 GMT From: Åke Wallebom <ake@ake.nu> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/119487: page fault in em taskq with polling enabled Message-ID: <200801091206.m09C6QeB002727@www.freebsd.org> Resent-Message-ID: <200801091210.m09CA3Pt009883@freefall.freebsd.org>
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>Number: 119487 >Category: kern >Synopsis: page fault in em taskq with polling enabled >Confidential: no >Severity: serious >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Jan 09 12:10:02 UTC 2008 >Closed-Date: >Last-Modified: >Originator: Åke Wallebom >Release: 7.0 RC1 >Organization: >Environment: FreeBSD dunder 7.0-RC1 FreeBSD 7.0-RC1 #2: Tue Jan 8 22:29:24 CET 2008 removed@dunder:/usr/obj/usr/src/sys/CUSTOM amd64 >Description: I got a page fault with 'current process' being 'em0 taskq' while transferring about 200 GB of data from an ftp server to my FreeBSD box via Gigabit LAN. I had compiled my kernel with DEVICE_POLLING and HZ=2000, and kern.polling.enable was set to 1 (I noticed later that this was deprecated). The files were transfered onto a ZFS pool on a GELI-device (1TB SATA2-drive). After transferring 150 GB i got the above error and the kernel panic'ed. Sadly, I can't remember the whole error message. More about the machine: Core 2 Duo E6750 4 GB RAM Three Intel PRO/1000 GT Desktop NICs (Single port cards) >How-To-Repeat: I really don't know... Hasn't happened again - but I have now recompiled the kernel with just 'POLLING' set, using default HZ now. And now i don't enable polling via sysctl but via ifconfig xxx polling. Transfered 180 GB and did not crash. So I guess I'm just reporting this as a curiosity for the em driver developer(s). >Fix: Decrease the HZ value? Set polling via ifconfig instead of kern.polling.enable? >Release-Note: >Audit-Trail: >Unformatted:
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