lftp crashes on Mac OS X 10.5 Leopard: 99% CPU usage due to bad poll()

[dackze@…]

On Leopard, lftp uses 99% CPU when idle due to poll() failing when being called on the tty device. You can see this with Instruments if you record lftp running with the "CPU Sampler" trace document, check "Invert Call Tree" and sort by "Total %". You can see it's on a tty with a dtrace script like "syscall::poll:entry { trace(fds[*(uint32_t *)copyin(arg0, 4)].fi_pathname); }".

lftp's configure script only uses its own poll() implementation if Darwin 8.* is being used, but Leopard is Darwin 9.0.0. Patching the configure script to add in a check for that doesn't actually seem to work for me though, as lftp still links to _poll$UNIX2003 and doesn't use its own implementation. I even went so far as to patch m4/lftp.m4's poll() test to account for the failure on device files, but it still ends up linking to _poll$UNIX2003. At this point I have no idea how to fix it. I'd appreciate it if someone else could take a look. I can post patches I've been messing with, if need be.

[nox@…]

Have you reported this bug upstream?

[dackze macports@…]

It's patched upstream in CVS, in revision 1.11 of m4/lftp.m4. The patch adds a test for poll() on devices.

I haven't been able to get its autogen.sh working on OS X though, so I haven't been able to test the patch.

[simon@…]

I updated lftp to version 3.6.1 ([31561]). But I'm not sure if this fixed this problem.

Simon

[mjhsieh@…]

I confirm that v3.6.1 DOES NOT fix this problem.

[nox@…]

Could you please try the following command?

sudo port -d build lftp configure.post_args="lftp_cv_func_poll_works=no"

[mjhsieh@…]

The result is the same.

/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_net_lftp\
/work/lftp-3.6.1/src/lftp
lftp :~>

in the other window,... the top still shows

  PID   UID  REG RPRVT  RSHRD  RSIZE  VPRVT  VSIZE  TH PRT    TIME  %CPU COMMAND
26754   501   51  352K   184K  1456K    74M    79M   1  13   8m11s  99.9 lftp

[mjhsieh@…]

The configuring log

[yunzheng.hu@…]

Sorry i opened up a new trac ticket a few days ago without checking first: #14242

I located the problem, and have a fix in that ticket.

[yunzheng.hu@…]

(Moving my initial comments of my ticket #14242 to this one.)

When compiling and running lftp on Leopard it causes the 'known' 100% cpu usage. This however is not entirely related to the 'poll' bug, like in Tiger.

I have attached a patch for configure that detects the broken poll on Leopard as well. And a modification to the Portfile that sets the MACOSX_DEPLOYMENT_TARGET=10.4, which fixes the cpu usage issue on Leopard.

references to the bug in Tiger:
​http://www.mail-archive.com/lftp%40uniyar.ac.ru/msg02101.html

same patch but for Leopard (but does not entirely fix the problem):
​http://www.mail-archive.com/lftp@uniyar.ac.ru/msg03091.html

[yunzheng.hu@…]

Modified Portfile that fixes the bug on leopard, also took maintainership (currently nomaintainer)

[yunzheng.hu@…]

patch for configure that also applies to Darwin 9 instead of only Darwin 8 (the poll issue)

[simon@…]

Committed in [34174]. I also added you as maintainer. Thanks for your help.

Simon

[anonymous]

Milestone Port Bugs deleted