lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 17 Oct 2008 12:33:01 -0200 From: Glauber Costa <glommer@...hat.com> To: Max Kellermann <mk@...all.com> Cc: linux-kernel@...r.kernel.org, gcosta@...hat.com, ijc@...lion.org.uk Subject: Re: [PATCH] NFS regression in 2.6.26?, "task blocked for more than 120 seconds" On Fri, Oct 17, 2008 at 02:32:07PM +0200, Max Kellermann wrote: > Hi, > > Ian: this is a follow-up to your post "NFS regression? Odd delays and > lockups accessing an NFS export" a few weeks ago > (http://lkml.org/lkml/2008/9/27/42). > > I am able to trigger this bug within a few minutes on a customer's > machine (large web hoster, a *lot* of NFS traffic). > > Symptom: with 2.6.26 (2.6.27.1, too), load goes to 100+, dmesg says > "INFO: task migration/2:9 blocked for more than 120 seconds." with > varying task names. Except for the high load average, the machine > seems to work. > > With git bisect, I was finally able to identify the guilty commit, > it's not "Ensure we zap only the access and acl caches when setting > new acls" like you guessed, Ian. According to my bisect, > 6becedbb06072c5741d4057b9facecb4b3143711 is the origin of the problem. > e481fcf8563d300e7f8875cae5fdc41941d29de0 (its parent) works well. > > Glauber: that is your patch "x86: minor adjustments for do_boot_cpu" > (http://lkml.org/lkml/2008/3/19/143). I don't understand this patch > well, and I fail to see a connection with the symptom, but maybe > somebody else does... > > See patch below (applies to 2.6.27.1). So far, it looks like the > problem is solved on the server, no visible side effects. > > Max That's probably something related to apic congestion. Does the problem go away if the only thing you change is this: > @@ -891,11 +897,6 @@ do_rest: > store_NMI_vector(&nmi_high, &nmi_low); > > smpboot_setup_warm_reset_vector(start_ip); > - /* > - * Be paranoid about clearing APIC errors. > - */ > - apic_write(APIC_ESR, 0); > - apic_read(APIC_ESR); > } Please let me know. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists