Re: Slow pipes after upgrade cygwin 1.5.12-1->1.5.13-1 when running boinc

[David Rothenberger <daveroth at acm dot org>]

On 3/3/2005 8:36 AM, Bengt-Arne Fjellner wrote:
> With boinc running einstein@home at lowest priority ( uses 100% cpu but yields easily)
> simple pipes takes a long time.
> Example: from a bash prompt
> echo hello|grep -v xyz
> with boinc running and 1.5.13-1 takes about 7 seconds.
> if i stop boinc it takes parts of a second.
> after downgrade to 1.5.12-1 with boinc running: parts of a second.
> 
> i have seen this on two different computers one HT one normal.

I was able to reproduce this without using BOINC.

I started two cmd.exe shells. In the first shell, I ran:

  sh -c 'nice -20 sh -c "while true; do :; done"'

Then, in the second cmd shell, I ran "sh" to start an ash shell I typed:

  echo hello | grep -v xyz

This takes several seconds to complete on a non-HT machine. It runs
quickly with 1.5.12.

I also noticed that if I ran

   sh -c 'echo hello | grep -v xyz'

from a cmd.exe shell, it completed quickly with 1.5.13.

The latest 20050303 snapshot fixed this problem for me. It also fixed
the problem I was having with BOINC.

-- 
David Rothenberger                spammer? -> spam@daveroth.dyndns.org
GPG/PGP: 0x7F67E734, C233 365A 25EF 2C5F C8E1 43DF B44F BA26 7F67 E734

To stand and be still,
At the Birkenhead drill,
Is a damned tough bullet to chew.
		-- Rudyard Kipling


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