long I/O delays when strace is running
Fri Apr 21 07:57:00 GMT 2017
On 04/20/2017 08:43 AM, Gluszczak, Glenn wrote:
> I haven't run Cygwin Expect for about 6 moths on Windows but it was behaving fine last time I did.
> One thing I am aware of is you can't interrupt sleep in TCL. The sleep must
> complete until the Control C is processed (regardless of whether you redirected signals
> to your own routines). Otherwise signals seemed to be processed immediately.
Please note that my simplified test case isn't using expect, but the
standard /usr/bin/sleep.exe -- this is just to have strace run and trace
for a longer amount of time in order to expose the problem. (it did get
broken into a new line though, so add a backslash:
> for ((i = 0; i < 64; ++i)); do strace --output=/tmp/sleep.$$.log \
> --trace-children --mask=startup sleep 64; done
> Perhaps some other service is interfering. You may want to disable other services.
I usually disable most services, I can probably disable a few more, but
I would like if somebody can run the above test case in one terminal
windows and in the other terminal window do a simple ps -ef and let me
know if ps responds immediately or has a delay. I am using Windows 7,
so it could be isolated to that windows version as well. When I do
this, ps has a 3 second delay while in
fhandler_base_overlapped::wait_overlapped, but I've seen this delay in
other processes while calling something like "open_shared."
Anyway, I'm going to try to find another simple test case that causes
more of a drastic delay.
Problem reports: http://cygwin.com/problems.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
More information about the Cygwin