From: Greg KH <greg@kroah.com>
To: linux-hotplug@vger.kernel.org
Subject: Re: [UDEV, PATCH] Add profiling support to Makefile
Date: Tue, 15 Feb 2005 23:10:49 +0000 [thread overview]
Message-ID: <20050215231049.GB16991@kroah.com> (raw)
In-Reply-To: <200502131716.55756.mbuesch@freenet.de>
On Tue, Feb 15, 2005 at 10:12:56AM +0100, Kay Sievers wrote:
> On Tue, 2005-02-15 at 09:45 +0100, Michael Buesch wrote:
> >Quoting Greg KH <greg@kroah.com>:
> >> On Sun, Feb 13, 2005 at 05:16:51PM +0100, Michael Buesch wrote:
> >> > Hi,
> >> >
> >> > This patch adds an option to the Makefile to enable
> >> > profiling. Profiling is only enabled, when not building
> >> > against klibc, as klibc lacks support for mcount().
> >> >
> >> > Please apply. Thanks.
> >>
> >> You forgot to update the documentation about this option, so I'll hold
> >> off till you redo that :)
> >
> >Oops. :O Here it is.
> >
> >> Also, what has profiling information helped you out with in udev? Found
> >> anything interesting? Or are you just using it for coverage analysis
> >> (which is a flawed thing, but that's another topic...)
> >
> >I did not do much testing, yet, because of missing time.
> >But I will do that.
> >My first testrun showed that the namedev matchrule function and the udevdb
> >are the slowest parts of the whole executable. So maybe there's some
> >optimization possible. But I'll look closer at it later.
>
> The biggest part of it seems libsysfs. A replacement of the attribute
> reading functions with a simple open() gives ~20% speed increase for
> udevstart on my box.
As I doubt libsysfs will be fixed in this regard anytime soon, want to
add this to the tree? A 20% speed increase for such a simple change is
a very good thing to have :)
thanks,
greg k-h
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prev parent reply other threads:[~2005-02-15 23:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-13 16:16 [UDEV, PATCH] Add profiling support to Makefile Michael Buesch
2005-02-15 3:54 ` Greg KH
2005-02-15 8:45 ` Michael Buesch
2005-02-15 9:12 ` Kay Sievers
2005-02-15 23:10 ` Greg KH [this message]
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