Public bug reported:
http process takes about 20% on intel i5-3317. Here is output of ps aux:
root 4309 21.7 0.0 37108 2344 pts/2 S+ 18:17 0:01
/usr/lib/apt/methods/http
it can be easy reproduces with "apt-get download firefox-dbg" or any
other upgrade realted command.
The reason of this overhead are this functions:
22,34% http libapt-pkg.so.4.12.0 [.] SHA256_Transform(_SHA256_CTX*, unsigned
int const*)
14,81% http libapt-pkg.so.4.12.0 [.] SHA512_Transform(_SHA512_CTX*, unsigned
long const*)
8,11% http libapt-pkg.so.4.12.0 [.] SHA1Transform(unsigned int*, unsigned
char const*)
5,62% http libapt-pkg.so.4.12.0 [.] MD5Transform(unsigned int*, unsigned int
const*)
libapt uses own implementation of this hasches without any optimisation. Are
there any reason why libapt do not use
openssl? Beside current version of openssl has AVX optimised SHA*
implementations.
ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: apt 0.9.7.7ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-4.9-generic 3.8.0-rc6
Uname: Linux 3.8.0-4-generic x86_64
ApportVersion: 2.8-0ubuntu4
Architecture: amd64
Date: Tue Feb 12 18:12:33 2013
InstallationDate: Installed on 2012-09-13 (152 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120913.1)
MarkForUpload: True
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=de_DE.UTF-8
SHELL=/bin/bash
SourcePackage: apt
UpgradeStatus: Upgraded to raring on 2013-02-06 (5 days ago)
** Affects: apt (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug raring running-unity
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1123272
Title:
high cpu usage on download (not optimised SHA256, SHA512, SHA1)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1123272/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
