linux-kernel - High sleep_on

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

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Date:	Mon, 16 Jan 2012 10:18:10 +0530
From:	Prateek Sharma <prateek3.14@...il.com>
To:	Linux Kernel <linux-kernel@...r.kernel.org>,
	kernelnewbies@...nelnewbies.org
Subject: High sleep_on_page latency

Hello,
  I am measuring system latency using latencytop. I am using kernel
version 3.0 with some minor changes.
The latencytop output for the process doing the IO (qemu) is below:

Process qemu-system-x86 (6239)             Total: 31363.7 msec
[sleep_on_page]                                   1966.5 msec         81.4 %
Waiting for event (select)                          5.0 msec          7.8 %
[kvm_vcpu_block]                                    5.0 msec          8.5 %
synchronous write                                   1.7 msec          0.0 %
Userspace lock contention                           1.5 msec          2.3 %

Is the 2000 msec sleep_on_page delays normal ? I would also like to
know what sleep_on_page exactly corresponds to. My understanding is
that it is the time spent waiting for grabbing a lock on a page. Is
this correct ?

Thanks.
--
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/