From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rolf Eike Beer Subject: Re: [PATCH 2/2] Add UAS driver Date: Thu, 30 Sep 2010 08:04:05 +0200 Message-ID: <201009300804.11861.eike-kernel@sf-tec.de> References: <1285668896-6356-1-git-send-email-willy@linux.intel.com> <201009281513.53869.oliver@neukum.org> <20100929005413.GB4689@linux.intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1537717.PBWT9tSkvM"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail.sf-mail.de ([62.27.20.61]:35803 "EHLO mail.sf-mail.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753533Ab0I3GES (ORCPT ); Thu, 30 Sep 2010 02:04:18 -0400 In-Reply-To: <20100929005413.GB4689@linux.intel.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: Oliver Neukum , greg@kroah.com, linux-usb@vger.kernel.org, linux-scsi@vger.kernel.org, sarah.a.sharp@linux.intel.com, Matthew Wilcox --nextPart1537717.PBWT9tSkvM Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Matthew Wilcox wrote: > On Tue, Sep 28, 2010 at 03:13:53PM +0200, Oliver Neukum wrote: > > Am Dienstag, 28. September 2010, 12:14:56 schrieb Matthew Wilcox: > > > + cmnd->result =3D sense_iu->status; > > > + if (sdev->current_cmnd) > > > + sdev->current_cmnd =3D NULL; > >=20 > > the condition is absolutely senseless >=20 > That's not true. Avoiding dirtying a cacheline is important for > performance. Go and tell your processor division to only mark a cacheline as dirty if it= =20 was actually changed by a write. They are throwing so much resources on thi= ngs=20 like SSE9 and the hell that they can probably afford doing that sort of=20 optimizations. Or they already do and this condition is absolutely senseles= s=20 ;) Eike --nextPart1537717.PBWT9tSkvM Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) iEYEABECAAYFAkykKFsACgkQXKSJPmm5/E5D9ACfcb5puun7YL6sXOEPKCOX0N39 sN4An1n0/HIDXM0HlltX8w9UAf+YsbI3 =9bpN -----END PGP SIGNATURE----- --nextPart1537717.PBWT9tSkvM--