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[Alberto Salvia Novella <es20490446e@xxxxxxxxx>]

** Changed in: apt (Ubuntu)
   Importance: Undecided => Medium

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https://bugs.launchpad.net/bugs/1123272

Title:
  high cpu usage on download (not optimised SHA256, SHA512, SHA1)

Status in apt package in Ubuntu:
  Confirmed

Bug description:
  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)

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