From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1BPqOz-0006Jq-5p for user-mode-linux-devel@lists.sourceforge.net; Mon, 17 May 2004 15:16:05 -0700 Received: from mail.gmx.net ([213.165.64.20]) by sc8-sf-mx1.sourceforge.net with smtp (Exim 4.30) id 1BPqOy-0002e3-EH for user-mode-linux-devel@lists.sourceforge.net; Mon, 17 May 2004 15:16:04 -0700 Message-ID: <03ff01c43c5d$7db6e5e0$2000000a@schlepptopp> From: "roland" References: <20040229043549.GA8583@ccure.user-mode-linux.org> <02dc01c43c4a$bb7c0490$2000000a@schlepptopp> <1084831251.1230.4.camel@chartreuse> Subject: Re: [uml-devel] [PATCH] host context switch reduction MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Tue, 18 May 2004 00:22:45 +0200 Content-Transfer-Encoding: quoted-printable To: Laurent Vivier Cc: user-mode-linux-devel@lists.sourceforge.net, Jeff Dike > If someone think this patch is really useful for 2.6 I can make the > port. for my personal opinion, every attempt to improve the performance of uml is= useful. :) the question is: is the "real world" performance benefit, uml get`s from this patch worth ta= king your time and is it implemented in a way, so that uml maintainers are happy with that ? i cannot really estimate, what performance benefits your patch brings to um= l in detail, but what i have seen so far, this seems quite worth doing the work. reducing context switches by 1/3 is a LOT, imh= o - and reducing the execution time of the getpid-loop to nearly the half is quite impressive. are there any "con`s" that argue for that work _NOT_ being done ? i would be a happy tester of a patch for 2.6 :) regards roland ----- Original Message -----=20 From: "Laurent Vivier" To: "roland" Cc: Sent: Tuesday, May 18, 2004 12:00 AM Subject: Re: [uml-devel] [PATCH] host context switch reduction > Hi, > > find hereunder the measurements I sent to Jeff. > > If someone think this patch is really useful for 2.6 I can make the > port. > > Regards, > Laurent > Please CC: me, as I'm not in the mailing list. > > Le lun 17/05/2004 =E0 22:08, roland a =E9crit : > > hi ! > > has this / will this be ported to 2.6 ? > > have there been made further performance comparisons ? > > regards > > roland > > > > > > >Well, we just looked at the context switches. We started 3 UMLs which > > >were doing a make world for xfree. Without patches the number of > > >context switches per second was around 60k, with the patch it was arou= nd > > >40k - so it's noticeable, at least from the cs. > > >Sven > > > > ----- Original Message -----=20 > > From: "Jeff Dike" > > To: > > Sent: Sunday, February 29, 2004 6:35 AM > > Subject: [uml-devel] [PATCH] host context switch reduction > > > > > > > The patches below are from Laurent Vivier who didn't make them public= . They > > > add a new feature to ptrace on the host which cuts down on the number= of > > > context switches needed for a UML system call, plus makes UML use it. > > > > > > There's some interest in this, so I'm putting it out as-is. I haven'= t played > > > with it. > > > > > > Laurent did some performance testing and found ~40% speedup on a getp= id > > > loop, and a 3.5% speedup on a kernel build. > > > > > > Jeff > > > > > > > ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=3D2562&alloc_id=3D6184&op=3Dclick _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel