From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753709Ab0KBAfM (ORCPT ); Mon, 1 Nov 2010 20:35:12 -0400 Received: from ozlabs.org ([203.10.76.45]:43376 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751995Ab0KBAfJ (ORCPT ); Mon, 1 Nov 2010 20:35:09 -0400 Subject: Re: [PATCH] drivers/char/hvc_console.c: reduce max idle timeout From: Michael Ellerman Reply-To: michael@ellerman.id.au To: Chris Metcalf Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org In-Reply-To: <201010271659.o9RGxrMc009847@farm-0002.internal.tilera.com> References: <201010271659.o9RGxrMc009847@farm-0002.internal.tilera.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-4k4D+9f+1rOX9vb6Ps6h" Date: Tue, 02 Nov 2010 11:35:08 +1100 Message-ID: <1288658108.16790.13.camel@concordia> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-4k4D+9f+1rOX9vb6Ps6h Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2010-10-27 at 12:54 -0400, Chris Metcalf wrote: > The tile architecture uses this framework for our serial console, > and our users complain that the delay of up to two seconds feels like > the machine has gone non-responsive and is disturbing. By contrast, > a delay of up to half a second feels like just the normal sort of > delay caused by swapping, network lag, etc. and is not noticeable. > The overhead is obviously not much greater. It's 4 times greater. We picked 2 seconds because it gave a reasonable trade off between responsiveness and load. I'm not convinced that half a second is a better number. cheers --=-4k4D+9f+1rOX9vb6Ps6h Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEABECAAYFAkzPXLwACgkQdSjSd0sB4dIPfwCdEiPhA3IsXqmoqmHBE/xKE7+3 YhwAoJC4YPrHS49jyJVGY4EmgyF5GCyG =Fa+n -----END PGP SIGNATURE----- --=-4k4D+9f+1rOX9vb6Ps6h--