| 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
| ||
|
Message-ID: <4F91769B.7000709@wanadoo.fr> Date: Fri, 20 Apr 2012 16:45:47 +0200 From: Pascal Chapperon <pascal.chapperon@...adoo.fr> To: paulmck@...ux.vnet.ibm.com CC: Josh Boyer <jwboyer@...hat.com>, linux-kernel@...r.kernel.org, kernel-team@...oraproject.org Subject: Re: RCU related performance regression in 3.3 Le 18/04/2012 17:23, Paul E. McKenney a écrit : >> systemd is controlling the whole boot process including mount >> operation (apart root filesystem) and as I can see, uses heavily >> sockets to do it (not to mention cpu-affinity). It controls also the >> major part of umount operations. Is it possible that your patch hits >> a systemd bug ? > > Is it possible that systemd is using network operations that include > synchronize_rcu()? Then if you did the same operation from the > command line at runtime, you might not see the slowdown. > > Is it possible for you to convince systemd to collect RCU event tracing > during the slow operation? RCU event tracing is available under > /sys/kernel/debug/tracing/rcu. > - Paul, thank you for these suggestions : I'll manage to enable RCU event tracing immediately after mounting debugfs (systemd permits custom units). As debugfs is mounted early in the boot sequence, maybe I'll catch something. Pascal -- 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