From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Thu, 28 May 2009 15:09:14 +0000 Subject: Re: [GIT] Experimental threaded udev Message-Id: List-Id: References: <4A1EA138.10400@tuffmail.co.uk> In-Reply-To: <4A1EA138.10400@tuffmail.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: linux-hotplug@vger.kernel.org On Thu, May 28, 2009 at 16:35, Alan Jenkins wrote: > Now available for your delight and/or horror. > > > > For now, I'm still treating this as a patch series.  That is, I may > publish future versions with a rewritten history.  I'll preserve the old > branches though. > > It turns out the MADV_DONTFORK hack I was so proud of is > implementation-dependant, i.e. a dirty hack.  However, I'm confident > that glibc can and should be modified to do it for all programs.  And it > is so worth it.  On my test machine, threading alone goes from 2s > boot-time coldplug to 1.3-ish.  MADV_DONTFORK takes it down to 0.7-ish. > The hack is contained in the last patch, "when forking a program, only > copy the stack of the _current_ thread". Is that a single or dual CPU box? With the threaded version, it's 0.18 (1.51 -> 1.33) seconds faster here for a full coldplug run on a: Intel(R) Core(TM)2 Duo CPU U9400 @ 1.40GHz. It might be that the threaded version will only behave that much better on a single CPU machine? Thanks, Kay