[Pkg-xfce-devel] Bug#777151: xfdesktop4: takes 100% cpu during network transfer and keeps doing that forever

[Jurriaan]

Package: xfdesktop4
Version: 4.10.2-3
Severity: important

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When I start X, xfdesktop is a mostly idle process as I'd expect.
When I transfer a file to my system with ncftp, xfdesktop starts to take 80%-100% cpu.
And it keeps on doing that, for minutes afterwards.
This is a i7-4790K system with 32 GiB memory and a SSD, so that is an insane amount of cpu time.

I can reproduce this - it always happens with file transfers and never happens without.
This is the result of strace -c (started during file transfer and ran for a few minutes afterwards,
ended while xfdesktop was still at 100% cpu):

Process 1337 attached
^CProcess 1337 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 31.89    0.004729           0   4748187   2849261 stat
 15.89    0.002356           0   2847137    949092 open
 15.56    0.002308           0   3796072    949018 access
 12.89    0.001911           0   2847055           lstat
  9.60    0.001423           0   2847076           read
  6.90    0.001024           0   1898044           close
  3.70    0.000548           0    949018           statfs
  3.43    0.000509           0    949025           fstat
  0.15    0.000022           0     27165      1071 futex
  0.00    0.000000           0        73           write
  0.00    0.000000           0       348           poll
  0.00    0.000000           0         5           mmap
  0.00    0.000000           0         5           munmap
  0.00    0.000000           0        10           brk
  0.00    0.000000           0        28           rt_sigprocmask
  0.00    0.000000           0       172           writev
  0.00    0.000000           0       518       343 recvmsg
------ ----------- ----------- --------- --------- ----------------
100.00    0.014830              20909938   4748785 total

grep stat xfdesktop4.log | sort | uniq -c | head -5:

 282003 fstat(10, {st_mode=S_IFREG|0644, st_size=1720, ...}) = 0
 564007 lstat("/home/jurriaan", {st_mode=S_IFDIR|0755, st_size=12288, ...}) = 0
 282003 lstat("/usr/share/icons/default.kde4/32x32/places/user-home.png", {st_mode=S_IFREG|0644, st_size=1720, ...}) = 0
      1 statfs("/home/jurriaan", {f_type="EXT2_SUPER_MAGIC", f_bsize=4096, f_blocks=64412515, f_bfree=52782739, f_bavail=49504992, f_files=16375808, f_ffree=16027008, f_fsid={-1009844909, -894125222}, f_namelen=255, f_frsize=4096}) = 0
      2 statfs("/home/jurriaan", {f_type="EXT2_SUPER_MAGIC", f_bsize=4096, f_blocks=64412515, f_bfree=52782740, f_bavail=49504993, f_files=16375808, f_ffree=16027008, f_fsid={-1009844909, -894125222}, f_namelen=255, f_frsize=4096}) = 0

grep open xfdesktop4.log | sort | uniq -c | sort -rn | head -5:

 564006 open("/usr/share/icons/default.kde4/32x32/places/user-home.png", O_RDONLY) = 10
 282003 open("/usr/share/icons/default.kde4/32x32/places/user-home.png", O_RDONLY|O_NOATIME) = -1 EPERM (Operation not permitted)
     25 open("/home/.hidden", O_RDONLY)         = -1 ENOENT (No such file or directory)

but that file seems perfectly readable (and I can cat it without problems)

ls -l /usr/share/icons/default.kde4/32x32/places/user-home.png
-rw-r--r-- 1 root root 1720 Apr 26  2011 /usr/share/icons/default.kde4/32x32/places/user-home.png

Kind regards,
Jurriaan

jurriaan_xfdesktopbug <insert AT sign here> onderneming10 . net

-- System Information:
Debian Release: 8.0
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 3.18.3 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages xfdesktop4 depends on:
ii  exo-utils           0.10.2-4
ii  libc6               2.19-14
ii  libcairo2           1.14.0-2.1
ii  libdbus-1-3         1.8.14-2
ii  libdbus-glib-1-2    0.102-1
ii  libexo-1-0          0.10.2-4
ii  libgarcon-1-0       0.2.1-2
ii  libgdk-pixbuf2.0-0  2.31.1-2+b1
ii  libglib2.0-0        2.42.1-1
ii  libgtk2.0-0         2.24.25-1
ii  libnotify4          0.7.6-2
ii  libpango-1.0-0      1.36.8-3
ii  libthunarx-2-0      1.6.3-2
ii  libwnck22           2.30.7-2
ii  libx11-6            2:1.6.2-3
ii  libxfce4ui-1-0      4.10.0-6
ii  libxfce4util6       4.10.1-2
ii  libxfconf-0-2       4.10.0-3
ii  xfdesktop4-data     4.10.2-3

Versions of packages xfdesktop4 recommends:
ii  dbus-x11         1.8.14-2
ii  librsvg2-common  2.40.5-1
ii  xdg-user-dirs    0.15-2

Versions of packages xfdesktop4 suggests:
ii  menu  2.1.47

-- no debconf information