Re: High Activity of setprogname

Re: High Activity of setprogname

[Sravan Bhamidipati]

Terminals like mintty and rxvt are doing an unusual amount of context
switching and consuming a lot of CPU cycles even in idle time. Process
Explorer suggests that this activity is largely attributable to
"cygwin1.dll!setprogname". Could this be something that should not or
need not be done? (Running cygwin.bat directly to use Cygwin doesn't
show such activity.)

Most recently I've been seeing this behavior with Mintty v0.97, Cygwin
v1.7.9-1, Windows 7 Ultimate SP1 (x64, Build Version: 6.1.7601 Service
Pack 1 Build 7601). However I've noticed this in a few older versions
of Mintty, Cygwin as well, even on Windows XP.

You can also view the mintty thread where this discussion began:
http://code.google.com/p/mintty/issues/detail?id=265

Regards,
Sravan

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

Re: Re: High Activity of setprogname

[Ryan Johnson]

On 2:59 PM, Sravan Bhamidipati wrote:
> Terminals like mintty and rxvt are doing an unusual amount of context
> switching and consuming a lot of CPU cycles even in idle time. Process
> Explorer suggests that this activity is largely attributable to
> "cygwin1.dll!setprogname". Could this be something that should not or
> need not be done? (Running cygwin.bat directly to use Cygwin doesn't
> show such activity.)
>
> Most recently I've been seeing this behavior with Mintty v0.97, Cygwin
> v1.7.9-1, Windows 7 Ultimate SP1 (x64, Build Version: 6.1.7601 Service
> Pack 1 Build 7601). However I've noticed this in a few older versions
> of Mintty, Cygwin as well, even on Windows XP.
>
> You can also view the mintty thread where this discussion began:
> http://code.google.com/p/mintty/issues/detail?id=265
The running code is related to select() (try running strace -mselect 
mintty to see for yourself).

A little poking around with windbg and gdb shows that select.cc:650 
(thread_pipe) is the culprit: select itself is called with infinite 
timeout; somebody more knowledgeable than me will have to explain why 
thread_pipe would return data so often for an idle process, however.

Ryan

P.S. Windows has no clue about gcc's symbols, which is why you got 
setprogname+0x2620 instead of something that made sense.


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

Re: Re: High Activity of setprogname

[Christopher Faylor]

On Thu, May 19, 2011 at 01:41:47PM -0400, Ryan Johnson wrote:
>On 2:59 PM, Sravan Bhamidipati wrote:
>> Terminals like mintty and rxvt are doing an unusual amount of context
>> switching and consuming a lot of CPU cycles even in idle time. Process
>> Explorer suggests that this activity is largely attributable to
>> "cygwin1.dll!setprogname". Could this be something that should not or
>> need not be done? (Running cygwin.bat directly to use Cygwin doesn't
>> show such activity.)
>>
>> Most recently I've been seeing this behavior with Mintty v0.97, Cygwin
>> v1.7.9-1, Windows 7 Ultimate SP1 (x64, Build Version: 6.1.7601 Service
>> Pack 1 Build 7601). However I've noticed this in a few older versions
>> of Mintty, Cygwin as well, even on Windows XP.
>>
>> You can also view the mintty thread where this discussion began:
>> http://code.google.com/p/mintty/issues/detail?id=265
>The running code is related to select() (try running strace -mselect 
>mintty to see for yourself).
>
>A little poking around with windbg and gdb shows that select.cc:650 
>(thread_pipe) is the culprit: select itself is called with infinite 
>timeout; somebody more knowledgeable than me will have to explain why 
>thread_pipe would return data so often for an idle process, however.

It's called "polling", see:

http://msdn.microsoft.com/en-us/library/aa365779%28v=vs.85%29.aspx

cgf

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple