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Re: slow bash spawn


Marc Compere wrote:
Dave Korn wrote:
On 18 March 2007 13:28, Marc Compere wrote:

The recent setup.exe update has caused bash.exe to have startup times
approx. 10x longer than before. sh.exe starts pretty quickly but bash.exe
[...]
Running XP sp2 on a fresh, plain vanilla cygwin install. antivirus is not
the problem as bash started just fine on cygwin release just a few weeks
ago.

Perhaps something in your startup scripts is taking this time. Open a dos
shell (start->run->"cmd"), cd to c:\cygwin\bin or whereever your install
lives, run "bash --login -i -x". The '-x' will make it print out all the
commands it's running during startup; hopefully you can narrow down the
problem to one particular item.


  Also, please run "cygcheck -s -v -r > cygcheck.out" and send the
cygcheck.out file ***as an attachment please*** with your next post.

    cheers,
      DaveK

Dave,


Your suggestions were good. I inspected the "bash --login -i -x" command from cmd.exe and found nothing in particular hanging although the hostname and "id -un" and "id -ng" took a little longer than the rest. Even silly simple things like a 'test' and short sed command all take an unusually long time.

I ran the cygcheck command similar to what you suggested:

cygcheck -s -v -r > /tmp/cygcheck.out 2>&1

and have attached. Also, as an example of generally slow access to the underlying XpSp2 os, an strace output of 'ls' is also attached. ls was never lighning fast in cygwin, but now it takes 2 seconds in a directory with 6 files in it. I can consistently get strace to show a burp that looks like this:
exception C0000005 at 18B5B7C3
right after a pair of:
_pinfo::set_ctty:
commands.


Complete details are in the attached strace output from command:

strace -o /tmp/strace_output_for_ls.txt ls

Any tips? Are you (or anyone else) able to discern any unusual incompatible dll's in the cygcheck.out or have any other hunches?

TIA again,
Marc


Well, it seems I've found the problem, or at least a big component of the problem. Turns out it is likely not (directly) related to cygwin code but some other interaction between cygwin and the OS as a result of a Sonic Solutions DLA process running. DLA apparantly stands for Drive Letter Access Component. Exact process name is c:\windows\system32\dla\dlactrlw.exe. Snapshot attached.


Being fed up with long XP boot-up times I had downloaded Autoruns and removed many, seemingly unnecessary startup processes and services. Oops, apparantly dlactrlw.exe is necessary for Cygwin to run quickly as usual. Never would have guessed - still don't quite understand how a Sonic cd burner software (I presume) causes the slow down, but it's pretty repeatable. 5 reboots later there's a 1-to-1 correspondence with this process and fast cygwin bash-related commands, including ./configure and make.

bash --login -i -x takes 33 seconds with DLA turned off (via Autoruns checkbox) and takes about 5.5 seconds with this process turned on. Go figure?

Thanks for all your thoughtful responses,

Marc





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