X-Recipient:	archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status:	No, hits=1.8 required=5.0 tests=AWL,BAYES_00,TW_DB,TW_RX,T_RP_MATCHES_RCVD
X-Spam-Check-By:	sourceware.org
Message-ID:	<4DD5565B.1070607@ece.cmu.edu>
Date:	Thu, 19 May 2011 13:41:47 -0400
From:	Ryan Johnson <ryanjohn AT ece DOT cmu DOT edu>
User-Agent:	Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10
MIME-Version:	1.0
To:	Sravan Bhamidipati <bsravanin AT gmail DOT com>
CC:	cygwin AT cygwin DOT com
Subject:	Re: Re: High Activity of setprogname
References:	<BANLkTinTO89ym2Jo=k3=d8ZJbcZ-j5nA9w AT mail DOT gmail DOT com>
In-Reply-To:	<BANLkTinTO89ym2Jo=k3=d8ZJbcZ-j5nA9w@mail.gmail.com>
X-IsSubscribed:	yes
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com

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

- Raw text -