From: Ken Brown <kbrown@cornell.edu>
To: cygwin@cygwin.com
Subject: Re: Performance problems with emacs-X11 in current cygwin
Date: Thu, 14 Jun 2012 19:48:00 -0000 [thread overview]
Message-ID: <4FDA3FE1.6070604@cornell.edu> (raw)
In-Reply-To: <4FDA3917.20309@cs.utoronto.ca>
On 6/14/2012 3:18 PM, Ryan Johnson wrote:
> On 13/06/2012 5:40 PM, Christopher Faylor wrote:
>> On Wed, Jun 13, 2012 at 05:07:17PM -0400, Ken Brown wrote:
>>> On 6/13/2012 2:40 PM, Ken Brown wrote:
>>>> On 6/10/2012 8:45 PM, Ken Brown wrote:
>>>>> The bisection shows that the first problematic commit is this one:
>>>>>
>>>>> http://git.gnome.org/browse/glib/commit/?h=glib-2-32&id=7eae486179e2799c369ed9ffcea663bf9161ce79
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Author: Ryan Lortie<desrt@desrt.ca>
>>>>> Date: Wed Aug 31 22:07:02 2011 -0400
>>>>>
>>>>> GMain: simplify logic for g_wakeup_acknowledge()
>>>>>
>>>>> Instead of messing around with context->poll_waiting, just look at the
>>>>> GPollFD to see if the GWakeup needs to be acknowledged.
>>>> I think this commit contains a typo: "events" should be "revents".
>>>> (context->wake_up_rec.events is always nonzero at this point in the
>>>> code, so it makes no sense to test that.) As a result,
>>>> g_wakeup_acknowledge() is being called much more often than
>>>> necessary. I
>>>> think this could easily explain the performance problems that have been
>>>> reported, but I won't have a chance to test this on my (slow) XP system
>>>> for a while, and possibly not until tomorrow.
>>> I've confirmed that fixing the typo solves the problem on my XP system.
>>> I suspect that this issue is not specific to XP after all and has more
>>> to do with the slowness of the machine, so that the performance problem
>>> is more noticeable. In any case, it's clearly a glib bug.
>>>
>>> I've filed a bug report upstream:
>>>
>>> https://bugzilla.gnome.org/show_bug.cgi?id=678052
>> What incredible perseverence you've shown in tracking this down. Bravo!
> ++
>
> Amazing. This is one of the nastier kinds of bugs I've seen anybody
> track down...
Thanks. I actually enjoyed learning some new things, though it was
frustrating at times.
Ken
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next prev parent reply other threads:[~2012-06-14 19:48 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-31 21:02 Angelo Graziosi
2012-06-01 11:01 ` Performance problems with emacs-X11 in current cygwin (attn: glib and gvim maintainer) Ken Brown
2012-06-01 11:21 ` atelp
2012-06-01 11:57 ` Ken Brown
2012-06-01 16:23 ` Stephen L
2012-06-01 18:39 ` Ken Brown
2012-06-01 19:10 ` K Stahl
2012-06-02 14:15 ` Performance problems with emacs-X11 in current cygwin Angelo Graziosi
2012-06-02 15:09 ` Ken Brown
2012-06-02 19:03 ` Ken Brown
2012-06-03 9:08 ` Yaakov (Cygwin/X)
2012-06-03 12:11 ` Ken Brown
2012-06-03 17:01 ` Ken Brown
2012-06-06 11:05 ` Stephen L
2012-06-08 12:59 ` Ken Brown
2012-06-08 15:33 ` Achim Gratz
2012-06-08 16:46 ` Ken Brown
2012-06-08 19:35 ` Andrey Repin
2012-06-11 0:45 ` Ken Brown
2012-06-11 2:54 ` Yaakov (Cygwin/X)
2012-06-11 11:39 ` Ken Brown
2012-06-11 15:11 ` Ken Brown
2012-06-12 13:02 ` Ken Brown
2012-06-11 13:56 ` K Stahl
2012-06-11 14:54 ` Ken Brown
2012-06-11 16:15 ` K Stahl
2012-06-11 17:59 ` Ken Brown
2012-06-11 18:56 ` K Stahl
2012-06-13 18:40 ` Ken Brown
2012-06-13 21:07 ` Ken Brown
2012-06-13 21:40 ` Christopher Faylor
2012-06-14 19:19 ` Ryan Johnson
2012-06-14 19:48 ` Ken Brown [this message]
2012-06-13 23:58 ` K Stahl
-- strict thread matches above, loose matches on Subject: below --
2012-06-05 6:29 Pach Roman (DGS-EC/ESG2)
[not found] <AF5E26A9B961BF4681B5C1593D7D03C020AFDD6C1D@SI-MBX06.de.bosch.com>
2012-06-04 15:49 ` Ken Brown
2012-06-01 6:17 Pach Roman (DGS-EC/ESG2)
2012-06-01 23:14 ` Ken Brown
2012-05-25 8:26 Angelo Graziosi
2012-05-30 11:26 ` Stephen L
2012-05-30 14:39 ` Ken Brown
2012-05-31 11:09 ` Stephen L
2012-05-31 13:06 ` Ken Brown
2012-05-24 12:37 Berglund Magnus (SE)
2012-05-24 13:01 ` Ken Brown
2012-05-24 14:51 ` K Stahl
2012-05-25 14:35 ` Ken Jackson
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