Bug#808579: apt: Very slow rred phase during update
Package: apt
Version: 1.1.5
Severity: normal
Since some time, the rred phase during aptitude/apt-get update is very
slow and produces very high system cpu-load.
Today I managed to get an strace of the relevant process (the one
matched by "pgrep -f rred", I don't know the exact name right now). It
does stuff like this:
2572 read(3, "P", 1) = 1
2572 read(3, "a", 1) = 1
2572 read(3, "c", 1) = 1
2572 read(3, "k", 1) = 1
2572 read(3, "a", 1) = 1
2572 read(3, "g", 1) = 1
2572 read(3, "e", 1) = 1
2572 read(3, ":", 1) = 1
2572 read(3, " ", 1) = 1
2572 read(3, "o", 1) = 1
2572 read(3, "p", 1) = 1
2572 read(3, "e", 1) = 1
2572 read(3, "n", 1) = 1
2572 read(3, "s", 1) = 1
2572 read(3, "l", 1) = 1
2572 read(3, "i", 1) = 1
2572 read(3, "d", 1) = 1
2572 read(3, "e", 1) = 1
2572 read(3, "-", 1) = 1
2572 read(3, "p", 1) = 1
2572 read(3, "y", 1) = 1
2572 read(3, "t", 1) = 1
2572 read(3, "h", 1) = 1
2572 read(3, "o", 1) = 1
2572 read(3, "n", 1) = 1
2572 read(3, "\n", 1) = 1
2572 write(4, "Package: openslide-python\n", 26) = 26
2572 read(3, "B", 1) = 1
2572 read(3, "i", 1) = 1
2572 read(3, "n", 1) = 1
Maybe buffering is disabled for some file descriptor where it should not
be?
-- Package-specific info:
-- (no /etc/apt/preferences present) --
-- (/etc/apt/sources.list present, but not submitted) --
-- System Information:
Debian Release: stretch/sid
APT prefers unstable
APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 4.3.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages apt depends on:
ii adduser 3.113+nmu3
ii debian-archive-keyring 2014.3
ii gnupg 1.4.19-6
ii gnupg2 2.1.10-3
ii gpgv 1.4.19-6
ii libapt-pkg5.0 1.1.5
ii libc6 2.21-4
ii libgcc1 1:5.3.1-4
ii libstdc++6 5.3.1-4
apt recommends no packages.
Versions of packages apt suggests:
pn apt-doc <none>
ii aptitude 0.7.5-3
ii dpkg-dev 1.18.3
ii python-apt 1.1.0~beta1
-- no debconf information
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